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MAKI Teruya

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FacultyDepartment of Life Science
PositionProfessor
DegreePh.D
Commentator Guidehttps://www.kindai.ac.jp/meikan/2457-maki-teruya.html
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Last Updated :2020/09/02

Education and Career

Education

  •   1992 04  - 1996 03 , Kyoto University, Faculty of Agriculture

Research Activities

Research Areas

  • Environmental science/Agricultural science, Environmental impact assessment

Research Interests

  • bacteria environmental chemicals phytoplankton

Published Papers

  • Release of Highly Active Ice Nucleating Biological Particles Associated with Rain, Ayumi Iwata, Mayu Imura, Moeka Hama, Teruya Maki, Nozomu Tsuchiya, Ryota Kunihisa, Atsushi Matsuki, Atmosphere, Atmosphere, 10(10), 605, Oct. 2019 , Refereed
  • Freshwater phytoplankton: biotransformation of inorganic arsenic to methylarsenic and organoarsenic, Hasegawa Hiroshi, Papry Rimana Islam, Ikeda Eri, Omori Yoshiki, Mashio Asami S, Maki Teruya, Rahman M. Azizur, SCIENTIFIC REPORTS, SCIENTIFIC REPORTS, 9, Aug. 19 2019 , Refereed
  • Comparative biotransformation and detoxification potential of arsenic by three macroalgae species in seawater: Evidence from laboratory culture studies, Al Mamun, M. Abdullah, Omori Yoshiki, Miki Osamu, Rahman Ismail M. M, Mashio Asami S, Maki Teruya, Hasegawa Hiroshi, CHEMOSPHERE, CHEMOSPHERE, 228, 117 - 127, Aug. 2019 , Refereed
  • Arsenic biotransformation potential of six marine diatom species: effect of temperature and salinity, Papry Rimana Islam, Ishii Kento, Al Mamun, M. Abdullah, Miah Sohag, Naito Kanako, Mashio Asami S, Maki Teruya, Hasegawa Hiroshi, SCIENTIFIC REPORTS, SCIENTIFIC REPORTS, 9, Jul. 15 2019 , Refereed
  • Vertical distributions of airborne microorganisms over Asian dust source region of Taklimakan and Gobi Desert, Teruya Maki, Chen Bin, Kenji Kai, Kei Kawai, Kazuyuki Fujita, Kazuma Ohara, Fumihisa Kobayashi, Enkhbaatar Davaanyam, Jun Noda, Yuki Minamoto, Guangyu Shi, Hiroshi Hasegawa, Yasunobu Iwasaka, Atmospheric Environment, Atmospheric Environment, 214, 116848-1 - 116848-8, Jul. 2019 , Refereed
  • Aeolian Dispersal of Bacteria Associated With Desert Dust and Anthropogenic Particles Over Continental and Oceanic Surfaces, Maki Teruya, Lee Kevin C, Kawai Kei, Onishi Kazunari, Hong Chun Sang, Kurosaki Yasunori, Shinoda Masato, Kai Kenji, Iwasaka Yasunobu, Archer Stephen D. J, Lacap-Bugler Donnabella C, Hasegawa Hiroshi, Pointing Stephen B, JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 124(10), 5579 - 5588, May 27 2019 , Refereed
  • Arsenic speciation and biotransformation by the marine macroalga Undaria pinnatifida in seawater: A culture medium study, Al Mamun M. Abdullah, Rahman Ismail M. M, Datta Rakhi Rani, Kosugi Chika, Mashio Asami S, Maki Teruya, Hasegawa Hiroshi, CHEMOSPHERE, CHEMOSPHERE, 222, 705 - 713, May 2019 , Refereed
  • Aeolian dispersal of bacteria associated with desert dust and anthropogenic particles over continental and oceanic surfaces, Teruya Maki, Kevin C. Lee, Kei Kawai, Kazunari Onishi, Chun Sang Hong, Yasunori Kurosaki, Masato Shinoda, Kenji Kai, Yasunobu Iwasaka, Stephen D. J. Archer, Donnabella C. Lacap-Bugler, Hiroshi Hasegawa, Stephen B. Pointing, Journal of Geophysical Research: Atmospheres, Journal of Geophysical Research: Atmospheres, 124(10), 5579 - 5588, Apr. 2019 , Refereed
  • Determination of multiple chelator complexes in aqueous matrices using ultra-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry, Miah Sohag, Rahman Ismail M. M, Takemura Masashi, Fukiage Shohei, Mashio Asami S, Maki Teruya, Hasegawa Hiroshi, TALANTA, TALANTA, 194, 980 - 990, Mar. 01 2019 , Refereed
  • Fungal spore involvement in the resuspension of radiocaesium in summer, Yasuhito Igarashi, Kazuyuki Kita, Teruya Maki, Takashi Kinase, Naho Hay ashi, Kentaro Hosaka, Kouji Adachi, Mizuo Kajino, Masahide Ishizuka, Tsuyoshi Thomas Sekiyama, Yuji Zaizen, Chisato Takenaka, Kazuhiko Ninomiy, Hiroshi Okochi, Atsuyuki Sorimachi, Scientific Reports, Scientific Reports, 9(154), Feb. 2019 , Refereed
  • Effect of biodegradable chelating ligands on Fe uptake in and growth of marine microalgae, Hasegawa Hiroshi, Nozawa Ayumi, Papry Rimana Islam, Maki Teruya, Miki Osamu, Rahman M. Azizur, JOURNAL OF APPLIED PHYCOLOGY, JOURNAL OF APPLIED PHYCOLOGY, 30(4), 2215 - 2225, Aug. 2018 , Refereed
  • Potential of proteins and their expression level in marine phytoplankton (Prymnesium parvum) as biomarker of N, P and Fe conditions in aquatic systems, H. Hasegawa, M. M. Rahman, S. Kato, T. Maki, M. A. Rahman, Advances in Biological Chemistry, Advances in Biological Chemistry, 3, 338 - 346, Jun. 2013
  • Epifluorescent Microscopic Observation of Aerosol, MAKI Teruya, HARA Kazunori, YAMADA Maromu, KOBAYASHI Fumihisa, HASEGAWA Hiroshi, IWASAKA Yasunobu, Earozoru Kenkyu, Earozoru Kenkyu, 28(3), 201 - 207, 2013
    Summary:Epifluorescent microscopy, coupled with fluorescence staining techniques, is useful for observations and quantitative estimation of airborne microbial communities (bioaerosols). Irradiation of short-wavelength excitation light onto a specimen results in luminescence of longer-wavelength fluorescence from materials in the specimen. Various fluorescent chemicals are used as stains bound to specific biomaterials. DAPI staining enables detection of all microbial cells in aerosol samples. Live/Dead staining method can estimate concentrations of both living and dead cells among microbial assemblages. Fluorescence in situ hybridization (FISH method) can be used as nucleotide probes for specific microbial species among bioaerosols. Epifluorescent microscopic observations provide information essential for elucidation of ecological characteristics of bioaerosols in atmospheric environments.
  • Ecophysiological analysis of halobacteria in bioaerosol, T. Maki, S. Susuki, F. Kobayashi, M. Kakikawa, M. Yamada, T. Higashi, C. Hong, Y. Tobo, H. Hasegawa, K. Ueda, Y. Iwasaka, Jouranal of Ecotechnology Research, Jouranal of Ecotechnology Research, 13 309-313, 2008
  • Seasonal dynamics of bacterial population degrading dimethylarsenic acid in Lake Kahokugata, W. Hirota, T. Maki, K. Ueda, T. Shimada, H. Hasegawa, K. Ueda, Jouranal of Ecotechnology Research, Jouranal of Ecotechnology Research, 2008
  • Seasonal dynamics of dimethylarsinic acid (DMAA) decomposing bacteria dominated in Lake Kahokugata, Maki T, Hasegawa H, Ueda K, APPLIED ORGANOMETALLIC CHEMISTRY, APPLIED ORGANOMETALLIC CHEMISTRY, Mar. 2005
  • Determination of minor and trace elements in biogenic carbonate minerals of coccolitho-phores by high-resolution inductively coupled plasma mass spectrometry., BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, 17, 209 - 211, Oct. 2002
  • Heterocapsa circularisquamaと海洋細菌の関係, 日本プランクトン学会報, 日本プランクトン学会報, 46(2), 172 - 177, Aug. 1999
  • Chelator-assisted washing for the extraction of lead, copper, and zinc from contaminated soils: A remediation approach, Hiroshi Hasegawa, M. Abdullah Al Mamun, Yoshinori Tsukagoshi, K. Ishii, Hikaru Sawai, Zinnat A. Begum, Mashio S. Asami, Teruya Maki, Ismail M.M. Rahman, Applied Geochemistry, Applied Geochemistry, 109(109), 104397 - 104406, Oct. 2019 , Refereed
    Summary:© 2019 Elsevier Ltd Chelators have proven to be effective extractants in soil washing and represent a suitable remediation technology for potentially toxic elements (PTEs) from contaminated sites. In this paper, the extraction of lead (Pb), copper (Cu), and zinc (Zn) from contaminated real and reference soils using both biodegradable (EDDS and HIDS) and persistent (EDTA and DTPA) chelators was investigated. Different metal–chelator complex formation constants, pH, extraction temperature, and mechanochemical energy were tested. The PTEs were extracted at a relatively higher rate under acidic to neutral conditions (pH 5 and 7), with the greatest extraction being observed at pH 5. The metal extraction efficiencies of the chelators for the real sample at pH 5 were as follows: Pb – EDTA > DTPA > EDDS > HIDS; Cu – DTPA > EDTA > EDDS > HIDS; and Zn – DTPA > EDTA > HIDS > EDDS. The data suggested that EDDS was more effective than HIDS for Cu and Zn extraction in neutral to slightly alkaline solutions, as well as at raised temperature. Furthermore, EDTA washing using mechanochemical agitation was found to enhance the removal efficiency of Cu and Zn. Sequential chemical extraction showed that the apparent metal mobilities were reduced by soil washing. EDTA and DTPA appeared to offer greater potential than the biodegradable chelators in extracting metals from the relatively mobile carbonate- and Fe–Mn oxide-bound fractions. The residual fraction of Pb displayed considerable stability (≥70%), and was not entirely amenable under washing treatments, and hence could be considered non-bioavailable and non-toxic.
  • Bioaccumulation and biotransformation of arsenic by the brown macroalga Sargassum patens C. Agardh in seawater: effects of phosphate and iron ions, M. Abdullah Al Mamun, Yoshiki Omori, Rimana Islam Papry, Chika Kosugi, Osamu Miki, Ismail M.M. Rahman, Asami S. Mashio, Teruya Maki, Hiroshi Hasegawa, Journal of Applied Phycology, Journal of Applied Phycology, 31(4), 2669 - 2685, Aug. 01 2019 , Refereed
    Summary:© 2019, Springer Nature B.V. The toxicity and bioaccumulation and biotransformation potential of inorganic arsenic (IAs) species As(V) and As(III) were investigated using Sargassum patens under laboratory culture for 7 days. Algal chlorophyll fluorescence decreased with increasing As(V) and As(III) concentrations, being significantly affected by As(III) treatments. Higher As(III) concentration negatively affected growth rate, and P and Fe limitation greatly enhanced IAs toxicity. The extracellular, intracellular, and total bioaccumulation of As(III) and As(V) varied significantly depending on initial concentrations and addition of P and Fe. P and Fe availability suppressed intracellular As accumulation in As(V) medium but not in As(III) medium. In P-rich (10 μmol L−1) medium, intracellular As was reduced by 4.7% and 9.9% when As(V) in the medium was constant (4.0 μmol L−1), under Fe-limited (0 μmol L−1) and Fe-rich (10 μmol L−1) conditions, respectively. However, the Fe-rich condition positively affected extracellular As accumulation from both As source. Extracellular As increased by 43.5% and 38.8% in P-limited + Fe-rich cultures with 4.0 μmol L−1 of As(V) and As(III), respectively. Algae exhibited greater absorption and adsorption to As(V) than to As(III). The reduced metabolites of As(III) (3.5 to 4.9% of the total As) and oxidized metabolites of As(V) (2.0 to 3.7% of the total As) were recorded as biotransformed species from coexisting media containing As(V) and As(III) at a constant 4.0 μmol L−1, respectively. Both P and Fe had significant influences on the variation in behaviors of IAs. This information is vital in terms of As research in marine ecosystems.
  • On-site analysis of gold, palladium, or platinum in acidic aqueous matrix using liquid electrode plasma-optical emission spectrometry combined with ion-selective preconcentration, Suman Barua, Ismail M.M. Rahman, Maho Miyaguchi, Asami S. Mashio, Teruya Maki, Hiroshi Hasegawa, Sensors and Actuators, B: Chemical, Sensors and Actuators, B: Chemical, 272, 91 - 99, Nov. 01 2018 , Refereed
    Summary:© 2018 Elsevier B.V. A technique for the concurrent on-site quantitative analysis of gold (Au), palladium (Pd), or platinum (Pt) in the aqueous acidic matrix has been proposed. The Au, Pd, or Pt in the matrix was selectively concentrated in macrocycle-equipped solid-phase extraction (SPE) system, followed by analysis of the concentrates in a portable liquid electrode plasma-optical emission spectrometer (LEP-OES). The SPE-retention or recovery behavior towards Au, Pd, or Pt has been optimized for solution pH, sample-loading flow-rates, eluent-type or eluent-volume, and matrix components. The SPE-assisted pre-treatment minimized interfering impacts due to the competing ions in solution and limitations in LEP-OES sensitivity at low Au, Pd, or Pt content in the matrix. The preconcentration factor was 250 for Au, Pd, or Pt. The LEP-OES operating variables such as applied voltage, on-time, off-time, and pulse count for applied voltage have been optimized to obtain distinct peaks in spectra for Au (λmax, 274.826 nm), Pd (λmax, 267.958 nm), and Pt (λmax, 270.240 nm). The limit of detection (3σ) for Au, Pd, Pt determination using the technique were found, respectively, as 0.8, 3.1, 57.3 ng mL−1. The proposed method was applied to the analysis of Au, Pd, or Pt contents in the European Commission Joint Research Center certified reference material of wastewaters (ERM-CA713; recovery by the standard addition method, >96%), and real aqueous waste from the plating process (recovery, >95%). A relative standard deviation of ≤ 5% indicated a good precision in Au, Pd, or Pt analysis using the technique. The LEP-OES data-sets were also comparable with those obtained from the inductively coupled plasma optical emission spectrometric measurements for the same matrix.
  • Environmental hazards associated with open-beach breaking of end-of-life ships: a review, Suman Barua, Ismail M.M. Rahman, Mohammad Mosharraf Hossain, Zinnat A. Begum, Iftakharul Alam, Hikaru Sawai, Teruya Maki, Hiroshi Hasegawa, Environmental Science and Pollution Research, Environmental Science and Pollution Research, 25(31), 30880 - 30893, Nov. 01 2018 , Refereed
    Summary:© 2018, Springer-Verlag GmbH Germany, part of Springer Nature. End-of-life (EOL) ships contribute significantly to the flow of recycled industrial Fe and non-Fe metal materials in resource-poor developing countries. The ship scrapping (breaking) and recycling industry (SBRI) recycles 90–95% of the total weight of EOL ships and is currently concentrated in Bangladesh, India, Pakistan, Turkey, and China, due to the high demand for recyclable and reusable materials there, an abundance of low-cost labor, and lenient environmental regulations. However, the SBRI has long been criticized for non-compliance with standards relating to occupational health, labor safety, and to the management of hazardous materials. Among the different EOL recycling options, Bangladesh, India, and Pakistan use open beaching, a technique that exposes all spheres of the environment to the release of hazardous materials from EOL ships. This article summarizes the current state of knowledge on the environmental exposure of hazardous materials from SBRI, to judge the risks associated with the dismantling of EOL ships on open beaches. Our work includes an overview of the industry and its recent growth, compares available ship-breaking methods, provides an inventory of hazardous releases from EOL ships, and reviews their movement into different spheres of the environment. The economic dynamics behind openbeaching, and apportionment of responsibility for hazards related to it, are discussed, in order to generate policy and legal recommendations to mitigate the environmental harm stemming from this industry.
  • Chelator-induced recovery of rare earths from end-of-life fluorescent lamps with the aid of mechano-chemical energy, Hiroshi Hasegawa, Zinnat A. Begum, Ryuta Murase, Kento Ishii, Hikaru Sawai, Asami S. Mashio, Teruya Maki, Ismail M.M. Rahman, Waste Management, Waste Management, 80, 17 - 25, Oct. 2018 , Refereed
    Summary:© 2018 Elsevier Ltd Rare-earths (REs) are key components for the transition to a greener energy profile and low carbon society. The elements turn out to be of limited availability in the market, due to the supply-demand issues, exponential price rises, or geopolitics, which has led to a focus on the exploration of secondary sources for RE reclamation. End-of-life (EoL) nickel-metal hydride batteries, permanent magnets, and fluorescent lamps (FL) have been the primary sources for recyclable REs, while the recovery of REs in EoL FL (Ce, Eu, La, Tb, or Y) includes comparatively fewer processing steps than the other potential sources. In the current work, we proposed a simple, energy-efficient protocol for EoL FL processing, using chelators in combination with ball milling. The parameters for optimum chelator-assisted recovery (chelator concentration, solid-to-liquid ratio, solution pH), and milling variables (ball size, ball weight, milling speed, milling duration), were evaluated at room temperature (RT, 25 ± 2 °C). The dissolution of REs with ethylenediaminetetraacetic acid (EDTA), ethylenediaminedisuccinic acid, methylglycinediacetic Acid, or 3-hydroxy-2,2′-iminodisuccinic acid, was compared at RT, while EDTA was used as the reference chelator throughout. Increasing the system temperature from 25 to 135 °C achieved at least double Eu and Y recovery, relative to that at RT, whereas the recovery rate improvement for Ce, La or Tb was insignificant. Mechano-chemical treatment at RT, via wet milling of EoL FL, with chelators, yielded a five order of magnitude increase in Ce, La and Tb recovery, however, plus a two-order increase for Eu or Y, compared with non-abetted operating conditions. It was also found that higher impact energy achieved improved recovery over a reduced milling duration with this technique having the added advantage of minimal acid consumption and reduced effluent production.
  • Long-range-transported bioaerosols captured in snow cover on Mount Tateyama, Japan: impacts of Asian-dust events on airborne bacterial dynamics relating to ice-nucleation activities, Teruya Maki, Shogo Furumoto, Yuya Asahi, Kevin C. Lee, Koichi Watanabe, Kazuma Aoki, Masataka Murakami, Takuya Tajiri, Hiroshi Hasegawa, Asami Mashio, Yasunobu Iwasaka, Atmospheric Chemistry and Physics, Atmospheric Chemistry and Physics, 18(11), 8155 - 8171, Jun. 08 2018 , Refereed
    Summary:The westerly wind travelling at high altitudes over eastern Asia transports aerosols from the Asian deserts and urban areas to downwind areas such as Japan. These long-range-transported aerosols include not only mineral particles but also microbial particles (bioaerosols), that impact the ice-cloud formation processes as ice nuclei. However, the detailed relations of airborne bacterial dynamics to ice nucleation in high-elevation aerosols have not been investigated. Here, we used the aerosol particles captured in the snow cover at altitudes of 2450 m on Mt Tateyama to investigate sequential changes in the ice-nucleation activities and bacterial communities in aerosols and elucidate the relationships between the two processes. After stratification of the snow layers formed on the walls of a snow pit on Mt Tateyama, snow samples, including aerosol particles, were collected from 70 layers at the lower (winter accumulation) and upper (spring accumulation) parts of the snow wall. The aerosols recorded in the lower parts mainly came from Siberia (Russia), northern Asia and the Sea of Japan, whereas those in the upper parts showed an increase in Asian dust particles originating from the desert regions and industrial coasts of Asia. The snow samples exhibited high levels of ice nucleation corresponding to the increase in Asian dust particles. Amplicon sequencing analysis using 16S rRNA genes revealed that the bacterial communities in the snow samples predominately included plant associated and marine bacteria (phyla Proteobacteria) during winter, whereas during spring, when dust events arrived frequently, the majority were terrestrial bacteria of phyla Actinobacteria and Firmicutes. The relative abundances of Firmicutes (Bacilli) showed a significant positive relationship with the ice nucleation in snow samples. Presumably, Asian dust events change the airborne bacterial communities over Mt Tateyama and carry terrestrial bacterial populations, which possibly induce ice-nucleation activities, thereby indirectly impacting climate change.
  • Selective recovery of gold, palladium, or platinum from acidic waste solution, Hiroshi Hasegawa, Suman Barua, Tomoya Wakabayashi, Asami Mashio, Teruya Maki, Yoshiaki Furusho, Ismail M.M. Rahman, Microchemical Journal, Microchemical Journal, 139, 174 - 180, Jun. 2018 , Refereed
    Summary:© 2018 Elsevier B.V. End-of-life electrical and electronic equipment is the potential secondary resource for economically-viable precious metals (PMs), e.g., gold (Au), palladium (Pd), or platinum (Pt). The hydrometallurgical processes produce acidic leachates during the recovery of PMs from waste sources, while the selective recovery of Au, Pd, or Pt from such a matrix is challenging either due to the chemical similarities of elements or complexities in the sources and matrices. A total of nine solid-phase extraction (SPE) systems, all claimed to designed for separation of PMs from complex matrices, was evaluated at varying solution pH (≤2 to 10) based on the selectivity towards Au, Pd, or Pt. The observation was used to develop a technique for selective Au, Pd, or Pt separation from acidic waste solutions using a macrocycle-equipped SPE. The feed solution flow-rates, eluent-type or compositions has been optimized to achieve maximum separation efficiency of the target analytes. The relative affinity of the macrocycles in solid-phase towards the ions (Pd > Au > Pt) is the core phenomenon of the proposed technique, and the host-guest type interaction is expected to be more stable than the resin-based separation processes. Furthermore, application of the macrocycle-equipped SPE system is advantageous regarding economics as it minimizes the impact of coexisting ions in the matrix and provides unaltered separation performance for several loading-elution cycles.
  • Characterization of atmospheric bioaerosols along the transport pathway of Asian dust during the Dust-Bioaerosol 2016 Campaign, Kai Tang, Zhongwei Huang, Jianping Huang, Teruya Maki, Shuang Zhang, Atsushi Shimizu, Xiaojun Ma, Jinsen Shi, Jianrong Bi, Tian Zhou, Guoyin Wang, Lei Zhang, Atmospheric Chemistry and Physics, Atmospheric Chemistry and Physics, 18(10), 7131 - 7148, May 24 2018 , Refereed
    Summary:Previous studies have shown that bioaerosols are injected into the atmosphere during dust events. These bioaerosols may affect leeward ecosystems, human health, and agricultural productivity and may even induce climate change. However, bioaerosol dynamics have rarely been investigated along the transport pathway of Asian dust, especially in China where dust events affect huge areas and massive numbers of people. Given this situation, the Dust- Bioaerosol (DuBi) Campaign was carried out over northern China, and the effects of dust events on the amount and diversity of bioaerosols were investigated. The results indicate that the number of bacteria showed remarkable increases during the dust events, and the diversity of the bacterial communities also increased significantly, as determined by means of microscopic observations with 4,6- diamidino-2-phenylindole (DAPI) staining and MiSeq sequencing analysis. These results indicate that dust clouds can carry many bacteria of various types into downwind regions and may have potentially important impacts on ecological environments and climate change. The abundances of DAPI-stained bacteria in the dust samples were 1 to 2 orders of magnitude greater than those in the non-dust samples and reached 105-106 particlesm 3. Moreover, the concentration ratios of DAPI-stained bacteria to yellow fluorescent particles increased from 5.1%-6.3% (non-dust samples) to 9.8%-6.3%(dust samples). A beta diversity analysis of the bacterial communities demonstrated the distinct clustering of separate prokaryotic communities in the dust and non-dust samples. Actinobacteria, Bacteroidetes, and Proteobacteria remained the dominant phyla in all samples. As for Erenhot, the relative abundances of Acidobacteria and Chloroflexi had a remarkable rise in dust events. In contrast, the relative abundances of Acidobacteria and Chloroflexi in non-dust samples of R-DzToUb were greater than those in dust samples. Alphaproteobacteria made the major contribution to the increasing relative abundance of the phylum Proteobacteria in all dust samples. The relative abundance of Firmicutes did not exceed 5% in all the air samples, even though it is the predominant phylum in the surface sand samples from the Gobi Desert. These results illustrate that the bacterial community contained in dust aerosol samples has a different pattern compared with non-dust aerosol samples, and the relative abundances of airborne bacteria are different from those in the surface sand or soil and differ by location and transmitting vector
  • Variations in airborne bacterial communities at high altitudes over the Noto Peninsula (Japan) in response to Asian dust events, Teruya Maki, Kazutaka Hara, Ayumu Iwata, Kevin C. Lee, Kei Kawai, Kenji Kai, Fumihisa Kobayashi, Stephen B. Pointing, Stephen Archer, Hiroshi Hasegawa, Yasunobu Iwasaka, Atmospheric Chemistry and Physics, Atmospheric Chemistry and Physics, 17(19), 11877 - 11897, Oct. 09 2017 , Refereed
    Summary:Aerosol particles, including airborne microorganisms, are transported through the free troposphere from the Asian continental area to the downwind area in East Asia and can influence climate changes, ecosystem dynamics, and human health. However, the variations present in airborne bacterial communities in the free troposphere over downwind areas are poorly understood, and there are few studies that provide an in-depth examination of the effects of long-range transport of aerosols (natural and anthropogenic particles) on bacterial variations. In this study, the vertical distributions of airborne bacterial communities at high altitudes were investigated and the bacterial variations were compared between dust events and non-dust events. Aerosols were collected at three altitudes from ground level to the free troposphere (upper level: 3000 or 2500 m middle level: 1200 or 500 m and low level: 10 m) during Asian dust events and non-dust events over the Noto Peninsula, Japan, where westerly winds carry aerosols from the Asian continental areas. During Asian dust events, air masses at high altitudes were transported from the Asian continental area by westerly winds, and laser imaging detection and ranging (lidar) data indicated high concentrations of nonspherical particles, suggesting that dust-sand particles were transported from the central desert regions of Asia. The air samples collected during the dust events contained 10-100 times higher concentrations of microscopic fluorescent particles and optical particle counter (OPC) measured particles than in non-dust events. The air masses of non-dust events contained lower amounts of dust-sand particles. Additionally, some air samples showed relatively high levels of black carbon, which were likely transported from the Asian continental coasts. Moreover, during the dust events, microbial particles at altitudes of > 1200m increased to the concentrations ranging from 1:2×106 to 6:6×106 particlesm-3. In contrast, when dust events disappeared, the microbial particles at> 1200mdecreased slightly to microbial-particle concentrations ranging from 6:4×104 to 8:9×105 particlesm-3. High-throughput sequencing technology targeting 16S rRNA genes (16S rDNA) revealed that the bacterial communities collected at high altitudes (from 500 to 3000 m) during dust events exhibited higher diversities and were predominantly composed of natural-sand/terrestrial bacteria, such as Bacillus members. During non-dust periods, airborne bacteria at high altitudes were mainly composed of anthropogenic/terrestrial bacteria (Actinobacteria), marine bacteria (Cyanobacteria and Alphaproteobacteria), and plantassociated bacteria (Gammaproteobacteria), which shifted in composition in correspondence with the origins of the air masses and the meteorological conditions. The airborne bacterial structures at high altitudes suggested remarkable changes in response to air mass sources, which contributed to the increases in community richness and to the domination of a few bacterial taxa.
  • Variations in airborne bacterial communities at high altitudes over the Noto Peninsula (Japan) in response to Asian dust events, Teruya Maki, Kazutaka Hara, Ayumu Iwata, Kevin C. Lee, Kei Kawai, Kenji Kai, Fumihisa Kobayashi, Stephen B. Pointing, Stephen Archer, Hiroshi Hasegawa, Yasunobu Iwasaka, ATMOSPHERIC CHEMISTRY AND PHYSICS, ATMOSPHERIC CHEMISTRY AND PHYSICS, 17(19), 11877 - 11897, Oct. 2017 , Refereed
    Summary:Aerosol particles, including airborne microorganisms, are transported through the free troposphere from the Asian continental area to the downwind area in East Asia and can influence climate changes, ecosystem dynamics, and human health. However, the variations present in airborne bacterial communities in the free troposphere over downwind areas are poorly understood, and there are few studies that provide an in-depth examination of the effects of long-range transport of aerosols (natural and anthropogenic particles) on bacterial variations. In this study, the vertical distributions of airborne bacterial communities at high altitudes were investigated and the bacterial variations were compared between dust events and non-dust events. Aerosols were collected at three altitudes from ground level to the free troposphere (upper level: 3000 or 2500 m;middle level: 1200 or 500 m; and low level: 10 m) during Asian dust events and non-dust events over the Noto Peninsula, Japan, where westerly winds carry aerosols from the Asian continental areas. During Asian dust events, air masses at high altitudes were transported from the Asian continental area by westerly winds, and laser imaging detection and ranging (lidar) data indicated high concentrations of nonspherical particles, suggesting that dust-sand particles were transported from the central desert regions of Asia. The air samples collected during the dust events contained 10-100 times higher concentrations of microscopic fluorescent particles and optical particle counter (OPC) measured particles than in non-dust events. The air masses of non-dust events contained lower amounts of dust-sand particles. Additionally, some air samples showed relatively high levels of black carbon, which were likely transported from the Asian continental coasts. Moreover, during the dust events, microbial particles at altitudes of > 1200m increased to the concentrations ranging from 1 : 2 x 106 to 6 : 6 x 10(6) particlesm 3. In contrast, when dust events disappeared, the microbial particles at > 1200mdecreased slightly to microbial-particle concentrations ranging from 6 : 4 x 10(4) to 8 : 9 x10(5) particles m(-3). High-throughput sequencing technology targeting 16S rRNA genes (16S rDNA) revealed that the bacterial communities collected at high altitudes (from 500 to 3000 m) during dust events exhibited higher diversities and were predominantly composed of natural-sand/terrestrial bacteria, such as Bacillus members. During non-dust periods, airborne bacteria at high altitudes were mainly composed of anthropogenic/ terrestrial bacteria (Actinobacteria), marine bacteria (Cyanobacteria and Alphaproteobacteria), and plantassociated bacteria (Gammaproteobacteria), which shifted in composition in correspondence with the origins of the air masses and the meteorological conditions. The airborne bacterial structures at high altitudes suggested remarkable changes in response to air mass sources, which contributed to the increases in community richness and to the domination of a few bacterial taxa.
  • Liquid electrode plasma-optical emission spectrometry combined with solid phase preconcentration for on-site analysis of lead, Suman Barua, Ismail M. M. Rahman, Iftakharul Alam, Maho Miyaguchi, Hikaru Sawai, Teruya Maki, Hiroshi Hasegawa, JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES, JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES, 1060, 190 - 199, Aug. 2017 , Refereed
    Summary:A relatively rapid and precise method is presented for the determination of lead in aqueous matrix. The method consists of analyte quantitation using the liquid electrode plasma-optical emission spectrometry (LEP-OES) coupled with selective separation/preconcentration by solid-phase extraction (SPE). The impact of operating variables on the retention of lead in SPEs such as pH, flow rate of the sample solution; type, volume, flow rate of the eluent; and matrix effects were investigated. Selective SPE-separation/preconcentration minimized the interfering effect due to manganese in solution and limitations in lead-detection in low-concentration samples by LEP-OES. The LEP-OES operating parameters such as the electrical conductivity of sample solution; applied voltage; on-time, off-time, pulse count for applied voltage; number of measurements; and matrix effects have also been optimized to obtain a distinct peak for the lead at lambda(max) = 405.8 nm. The limit of detection (3 sigma) and the limit of quantification (10 sigma) for lead determination using the technique were found as 1.9 and 6.5 ng mL(-1), respectively. The precision, as relative standard deviation, was lower than 5% at 0.1 mu g mL(-1) Pb, and the preconcentration factor was found to be 187. The proposed method was applied to the analysis of lead contents in the natural aqueous matrix (recovery rate: > 95%). The method accuracy was verified using certified reference material of wastewaters: SPS-WW1 and ERM-CA713. The results from LEP-OES were in good agreement with inductively coupled plasma optical emission spectrometry measurements of the same samples. The application of the method is rapid (<= 5 min, without preconcentration) with a reliable detection limit at trace levels.
  • Global Diversity of Desert Hypolithic Cyanobacteria, Donnabella C. Lacap-Bugler, Kevin K. Lee, Stephen Archer, Len N. Gillman, Maggie C. Y. Lau, Sebastian Leuzinger, Charles K. Lee, Teruya Maki, Christopher P. McKay, John K. Perrott, Asuncion de los Rios-Murillo, Kimberley A. Warren-Rhodes, David W. Hopkins, Stephen B. Pointing, FRONTIERS IN MICROBIOLOGY, FRONTIERS IN MICROBIOLOGY, 8, May 2017 , Refereed
    Summary:Global patterns in diversity were estimated for cyanobacteria-dominated hypolithic communities that colonize ventral surfaces of quartz stones and are common in desert environments. A total of 64 hypolithic communities were recovered from deserts on every continent plus a tropical moisture sufficient location. Community diversity was estimated using a combined t-RFLP fingerprinting and high throughput sequencing approach. The t-RFLP analysis revealed desert communities were different from the single non-desert location. A striking pattern also emerged where Antarctic desert communities were clearly distinct from all other deserts. Some overlap in community similarity occurred for hot, cold and tundra deserts. A further observation was that the producer-consumer ratio displayed a significant negative correlation with growing season, such that shorter growing seasons supported communities with greater abundance of producers, and this pattern was independent of macroclimate. High-throughput sequencing of 16S rRNA and nifH genes from four representative samples validated the t-RFLP study and revealed patterns of taxonomic and putative diazotrophic diversity for desert communities from the Taklimakan Desert, Tibetan Plateau, Canadian Arctic and Antarctic. All communities were dominated by cyanobacteria and among these 21 taxa were potentially endemic to any given desert location. Some others occurred in all but the most extreme hot and polar deserts suggesting they were relatively less well adapted to environmental stress. The t-RFLP and sequencing data revealed the two most abundant cyanobacterial taxa were Phormidium in Antarctic and Tibetan deserts and Chroococcidiopsis in hot and cold deserts. The Arctic tundra displayed a more heterogenous cyanobacterial assemblage and this was attributed to the maritime-influenced sampling location. The most abundant heterotrophic taxa were ubiquitous among samples and belonged to the Acidobacteria, Actinobacteria, Bacteroidetes, and Proteobacteria. Sequencing using nitrogenase gene-specific primers revealed all putative diazotrophs were Proteobacteria of the orders Burkholderiales, Rhizobiales, and Rhodospirillales. We envisage cyanobacterial carbon input to the system is accompanied by nitrogen fixation largely from non-cyanobacterial taxa. Overall the results indicate desert hypoliths worldwide are dominated by cyanobacteria and that growing season is a useful predictor of their abundance. Differences in cyanobacterial taxa encountered may reflect their adaptation to different moisture availability regimes in polar and non-polar deserts.
  • Variations in the structure of airborne bacterial communities in Tsogt-Ovoo of Gobi desert area during dust events, Teruya Maki, Yasunori Kurosaki, Kazunari Onishi, Kevin C. Lee, Stephen B. Pointing, Dulam Jugder, Norikazu Yamanaka, Hiroshi Hasegawa, Masato Shinoda, AIR QUALITY ATMOSPHERE AND HEALTH, AIR QUALITY ATMOSPHERE AND HEALTH, 10(3), 249 - 260, Apr. 2017 , Refereed
    Summary:Asian dust events transport the airborne bacteria in Chinese desert regions as well as mineral particles and influence downwind area varying biological ecosystems and climate changes. However, the airborne bacterial dynamics were rarely investigated in the Gobi desert area, where dust events are highly frequent. In this study, air samplings were sequentially performed at a 2-m high above the ground at the sampling site located in desert area (Tsogt-Ovoo of Gobi desert; Mongolia 44.2304A degrees N, 105.1700A degrees E). During the dust event days, the bacterial cells and mineral particles increased to more than tenfold of concentrations. MiSeq sequencing targeting 16S ribosomal DNA revealed that the airborne bacteria in desert area mainly belonged to the classes Acidobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Bacilli, Alpha-proteobacteria, Beta-proteobacteria, and Gamma-proteobacteria. The bacterial community structures were different between dust events and non-dust events. The air samples collected at the dust events indicated high abundance rates of Alpha-proteobacteria, which were reported to dominate on the leaf surfaces of plants or in the saline lake environments. After the dust events, the members of Firmicutes (Bacilli) and Bacteroidetes, which are known to form endospore and attach with coarse particles, respectively, increased their relative abundances in the air samples. Presumably, the bacterial compositions and diversities in atmosphere significantly vary during dust events, which carry some particles from grassland (phyllo-sphere), dry lake, and sand surfaces, as well as some bacterial populations such as Firmicutes and Bacteroidetes maintain in the atmosphere for longer time.
  • Laboratory culture experiments to study the effect of lignite humic acid fractions on iron solubility and iron uptake rates in phytoplankton, Hiroshi Hasegawa, Yousuke Tate, Masashi Ogino, Teruya Maki, Zinnat A. Begum, Toshiharu Ichijo, Ismail M. M. Rahman, JOURNAL OF APPLIED PHYCOLOGY, JOURNAL OF APPLIED PHYCOLOGY, 29(2), 903 - 915, Apr. 2017 , Refereed
    Summary:The major fractions of dissolved iron in seawater exist as a complex with organic ligands. A high bioavailability of iron bound to humic acid (HA) compared to the other model ligands, such as desferrioxamine B or ferrichrome, has been reported, which implies the importance of HA to control the geochemical behavior and the transfer of Fe to marine phytoplankton, particularly in estuarine and coastal waters. In the current work, the effect of different HA fractions (> 100, 100-30, 30-10, 10-5, and 5-3 kDa), which were extracted from lignite, on the comparative solubility of iron in seawater and the corresponding influence on iron uptake and growth rate of the phytoplankton Prymnesium parvum (Haptophyta) was studied using laboratory cultures. The lower-molecular-weight (MW) HA fractions, such as 30-10, 10-5, and 5-3 kDa, remained soluble in the simulated seawater medium for a longer time span compared to the higher MW fractions. The lower MW fractions facilitated higher iron solubility and assisted in achieving a better phytoplankton growth rate. However, a reciprocal impact on phytoplankton growth rates was observed when the HA concentration increased to a higher range (0.18 to 18 mg-C L-1). The highest intracellular Fe uptake in phytoplankton occurred with 30-10 kDa HA in seawater, and the extracellular dissolved Fe concentrations were higher for smaller-sized HA fractions. In summary, our study showed that the controlled addition of lower MW fractions of HA (up to 30-10 kDa) in estuarine waters could ensure the accelerated uptake of Fe in phytoplankton as well as a better growth rate.
  • Atmospheric aerosol deposition influences marine microbial communities in oligotrophic surface waters of the western Pacific Ocean, Teruya Maki, Akira Ishikawa, Tomoki Mastunaga, Stephen B. Pointing, Yuuki Saito, Tomoaki Kasai, Koichi Watanabe, Kazuma Aoki, Amane Horiuchi, Kevin C. Lee, Hiroshi Hasegawa, Yasunobu Iwasaka, DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS, DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS, 118, 37 - 45, Dec. 2016 , Refereed
    Summary:Atmospheric aerosols contain particulates that are deposited to oceanic surface waters. These can represent a major source of nutrients, trace metals, and organic compounds for the marine environment. The Japan Sea and the western Pacific Ocean are particularly affected by aerosols due to the transport of desert dust and industrially derived particulate matter with aerodynamic diameter less than 2.5 mu m (PM2.5) from continental Asia. We hypothesized that supplementing seawater with aerosol particulates would lead to measurable changes in surface water nutrient composition as well as shifts in the marine microbial community. Shipboard experiments in the Pacific Ocean involved the recovery of oligotrophic oceanic surface water and subsequent supplementation with aerosol particulates obtained from the nearby coastal mountains, to simulate marine particulate input in this region. Initial increases in nitrates due to the addition of aerosol particulates were followed by a decrease correlated with the increase in phytoplankton biomass, which was composed largely of Bacillariophyta (diatoms), including Pseudo-nitzschia and Chaetoceros species. This shift was accompanied by changes in the bacterial community, with apparent increases in the relative abundance of heterotrophic Rhodobacteraceae and Colwelliaceae in aerosol particulate treated seawater. Our findings provide empirical evidence revealing the impact of aerosol particulates on oceanic surface water microbiology by alleviating nitrogen limitation in the organisms.
  • Effects of different temperature treatments on biological ice nuclei in snow samples, Kazutaka Hara, Teruya Maki, Makiko Kakikawa, Fumihisa Kobayashi, Atsushi Matsuki, ATMOSPHERIC ENVIRONMENT, ATMOSPHERIC ENVIRONMENT, 140, 415 - 419, Sep. 2016 , Refereed
    Summary:The heat tolerance of biological ice nucleation activity (INA) depends on their types. Different temperature treatments may cause varying degrees of inactivation on biological ice nuclei (IN) in precipitation samples. In this study, we measured IN concentration and bacterial INA in snow samples using a drop freezing assay, and compared the results for unheated snow and snow treated at 40 degrees C and 90 degrees C. At a measured temperature of -7 degrees C, the concentration of IN in untreated snow was 100-570 L-1, whereas the concentration in snow treated at 40 degrees C and 90 degrees C was 31-270 L-1 and 2.5-14 L-1, respectively. In the present study, heat sensitive IN inactivated by heating at 40 degrees C were predominant, and ranged 23-78% of IN at -7 degrees C compared with untreated samples. Ice nucleation active Pseudomonas strains were also isolated from the snow samples, and heating at 40 degrees C and 90 degrees C inactivated these microorganisms. Consequently, different temperature treatments induced varying degrees of inactivation on IN in snow samples. Differences in the concentration of IN across a range of treatment temperatures might reflect the abundance of different heat sensitive biological IN components. (C) 2016 Elsevier Ltd. All rights reserved.
  • Phylogenetic analysis of bacterial species compositions in sand dunes and dust aerosol in an Asian dust source area, the Taklimakan Desert, Findya Puspitasari, Teruya Maki, Guangyu Shi, Chen Bin, Fumihisa Kobayashi, Hiroshi Hasegawa, Yasunobu Iwasaka, AIR QUALITY ATMOSPHERE AND HEALTH, AIR QUALITY ATMOSPHERE AND HEALTH, 9(6), 631 - 644, Sep. 2016 , Refereed
    Summary:Airborne microorganisms (bioaerosol) from the China desert region, which are released into the atmosphere, disperse by the Asian dust event and affect ecosystems, human life, and atmospheric processes in downwind areas. However, the dynamics of airborne bacteria over the China desert regions have rarely been investigated. In this study, we analyzed bacterial communities in aerosols of the Asian dust source region (Taklimakan Desert) and compared them with the bacterial communities in sand dunes, for evaluating the mixtures from sand area to atmosphere. Air samples were collected at 10 m above the ground level from Dunhuang City during a dust event. The cell densities of airborne bacteria during a dust event were ten times more than that in non-dust periods. The 16S rDNA clone libraries from four air samples mainly belonged to two phyla, Firmicutes and Proteobacteria. During a dust event, the proportion of Proteobacteria clones decreased, whereas that of Firmicutes clones increased. Sand samples were collected from the sand dunes in four sampling sites of the Taklimakan Desert. The bacterial communities in sand samples comprised of the members of Firmicutes and Actinobacteria. The clones of Firmicutes in both air and sand samples included Bacillus species, constituting more than 10 % of total clones. Airborne bacterial communities would be carried by the dust events from sand dunes. Propionibacterium species from the class Actinobacteria that were dominant in sand samples were not detected in the air samples, suggesting that atmospheric stressors eliminate some bacterial species. Presumably, airborne bacterial communities in the Asian dust source region are composed of local environmental bacteria, and their dynamics depend on the occurrence of a dust event.
  • Decontamination of metal-contaminated waste foundry sands using an EDTA-NaOH-NH3 washing solution, Hikaru Sawai, Ismail M. M. Rahman, Mayuko Fujita, Naoyuki Jii, Tomoya Wakabayashi, Zinnat A. Begum, Teruya Maki, Satoshi Mizutani, Hiroshi Hasegawa, CHEMICAL ENGINEERING JOURNAL, CHEMICAL ENGINEERING JOURNAL, 296, 199 - 208, Jul. 2016 , Refereed
    Summary:Waste foundry sand (WFS), which is a hazardous byproduct from the foundry industry, is often contaminated with potentially toxic elements (PTEs), such as Cu, Pb and Zn, and widely re-utilized as a construction_ material. Therefore, the depollution of WFS has been suggested due to its environment friendly reprocessing to avoid potential long-term hazardous impacts. In the current study, a unique chemically induced technique has been proposed for the removal of PTEs from WFS. EDTA, NaOH and NH3 were used as extractants in combination or in succession. The optimum removal of PTEs was accomplished using a solid (WFS) to solution (50 mmol L-1 EDTA) ratio of 10 under strongly basic pH conditions, which was achieved with NaOH addition. The washing efficiency was further enhanced with the addition of NH3 to the solution. The complete process cycle duration was adjusted to 9 h with a washing sequence that was repeated three times for 3 h each. The ultimate efficiencies (%) for the removal of PTEs were as follows: Cu, 98; Pb, 81; Sn, 83; and Zn, 50. The leaching of residual PTEs (%) from the decontaminated WFS was also in compliance with the regulatory levels that are defined by the monitoring authorities. (C) 2016 Elsevier By. All rights reserved.
  • Atmospheric bioaerosols originating from Adelie penguins (Pygoscelis adeliae): Ecological observations of airborne bacteria at Hukuro Cove, Langhovde, Antarctica, Fumihisa Kobayashi, Teruya Maki, Makiko Kakikawa, Takuji Noda, Hiromichi Mitamura, Akinori Takahashi, Satoshi Imura, Yasunobu Iwasaka, POLAR SCIENCE, POLAR SCIENCE, 10(1), 71 - 78, Mar. 2016 , Refereed
    Summary:The relationship between atmospheric bioaerosols and ecosystems is currently of global importance. Antarctica has an extreme climate, meaning that ecosystem behavior in this region is relatively simple. Direct sampling of atmospheric bioaerosols was performed at an Adelie penguin (Pygoscelis adeliae) colony at Hukuro Cove, Langhovde, Antarctica on 22 January 2013. The aim of the sampling was to reveal the effect of the penguins on the Antarctic ecosystem within the atmospheric bioaerosols. Samples were bio-analyzed using a next-generation sequencing method. Biomass concentrations of Bacilli-class bacteria were 19.4 times higher when sampled leeward of the penguin colony compared with windward sampling. The source of these bacteria was the feces of the penguins. Predicted atmospheric trajectories indicate that the bacteria disperse towards the Southern Ocean. The largest biomass concentration in the windward bacteria was of the Gammaproteobacteria class, which decreased markedly with distance through the penguin colony, being deposited on soil, surface water, and ocean. It is concluded that bioaerosols and ecosystems near the penguin colony strongly influence each other. (C) 2015 Elsevier B.V. and NIPR. All rights reserved.
  • Evaluation of the toxicity of a Kosa (Asian duststorm) event from view of food poisoning: observation of Kosa cloud behavior and real-time PCR analyses of Kosa bioaerosols during May 2011 in Kanazawa, Japan, Fumihisa Kobayashi, Kana Iwata, Teruya Maki, Makiko Kakikawa, Tomomi Higashi, Maromu Yamada, Takamichi Ichinose, Yasunobu Iwasaka, AIR QUALITY ATMOSPHERE AND HEALTH, AIR QUALITY ATMOSPHERE AND HEALTH, 9(1), 3 - 14, Feb. 2016 , Refereed
    Summary:Kosa (Asian duststorm) is a well-known phenomenon where particles are transported from Mongolia and northwestern China via Eastern Asia to the American continent. Kosa bioaerosols (airborne microorganisms within Kosa) were frequently found during Kosa event, and there is concern that they may affect human health. For biological observation and evaluation of Kosa events, we made sampling of aerosols in Kosa events on May 2 (KOSA1) and May 13 (KOSA2), 2011, at Kanazawa, Japan. From the data of lidar from Toyama, SPRINTARS simulation model and the backward trajectories of air masses, both events were originated in desert area of Mongolia. KOSA episode 1 was stronger than KOSA episode 2 above the surface boundary layer, and KOSA episode 2 contained the particles from the local source such as soil, sea salt, and various particles formed in the polluted atmosphere. The DNA to total suspended particle matter (SPM) ratios in KOSA1 and KOSA2 were 0.012 and 0.00978, respectively. Bacterial species compositions were identified qualitatively. Many Gammaproteobacteria were cloned and identified from both KOSA. Quantitative toxicity observations to assess the risk of food poisoning were performed by real-time PCR of food poisoning bacteria, Bacillus and Staphylococcus spp. The ratios of the concentrations of Bacillus and Staphylococcus spp. relative to SPM in KOSA1 and KOSA2 were 33.1 and 43.1 copies mu g-SPM-1, respectively. The results of toxicity evaluations by the mathematical simulations suggested that compared with KOSA1, KOSA2 had a 1.35 times higher risk of causing food poisoning.
  • Variations of ice nuclei concentration induced by rain and snowfall within a local forested site in Japan, Kazutaka Hara, Teruya Maki, Fumihisa Kobayashi, Makiko Kakikawa, Masashi Wada, Atsushi Matsuki, ATMOSPHERIC ENVIRONMENT, ATMOSPHERIC ENVIRONMENT, 127, 1 - 5, Feb. 2016 , Refereed
    Summary:Biological ice nuclei (IN) such as certain species of bacteria and fungi are believed to have impacts on ice nucleation in mixed-phase clouds at temperatures warmer than -15 degrees C. Recent studies have indicated that rain is closely related to increases of biological IN in the near-surface atmosphere. However, variations of IN concentrations during rain and snowfall have not been compared. In the present study, field measurements of atmospheric IN were carried out under fine, cloudy, rain and snow at a local forested site in Japan. IN concentrations at -7 degrees C in spring were dramatically increased by rain, and concentrations associated with rain (0.86-2.2 m(-3)) were greater than 2.6 times higher than the mean concentration during fine weather (0.33 m(-3)). In winter, concentrations associated with rain (1.6 to >5.7 m(-3)) were also higher than those under cloudy sky (1.1 m(-3)), but increases were not observed during snowfall (0.21-0.4 m(-3)). Detectable IN concentrations associated with rain considerably decreased after heat treatment at 90 degrees C, indicating that IN increased during rain were likely biological substances such as heat-sensitive ice nucleation active proteins. Consequently, different types of precipitation may have varying effects on IN concentration associated with biological substances. (C) 2015 Elsevier Ltd. All rights reserved.
  • Silica-carrying particulate matter enhances Bjerkandera adusta-induced murine lung eosinophilia, Miao He, Takamichi Ichinose, Boying Liu, Yuan Song, Yasuhiro Yoshida, Fumihisa Kobayashi, Teruya Maki, Seiichi Yoshida, Masataka Nishikawa, Hirohisa Takano, Guifan Sun, ENVIRONMENTAL TOXICOLOGY, ENVIRONMENTAL TOXICOLOGY, 31(1), 93 - 105, Jan. 2016 , Refereed
    Summary:Bjerkandera adusta (B. adusta) causes fungus-associated chronic cough. However, the inflammatory response is not yet fully understood. Recently, B. adusta was identified in Asian sand dust (ASD) aerosol. This study investigated the enhancing effects of ASD on B. adusta-induced lung inflammation. B. adusta was inactivated by formalin. ASD was heated to remove toxic organic substances. ICR mice were intratracheally instilled with saline, B. adusta 0.2 mu g, or B. adusta 0.8 mu g with or without heated ASD 0.1 mg (H-ASD), four times at 2-week intervals. Two in vitro experiments were conducted to investigate any enhancing effects using bone marrow-derived macrophages (BMDM) from Toll-like receptor (TLR) knockout mice and ICR mice. Co-exposure to H-ASD and B. adusta, especially at high doses, caused eosinophil infiltration, proliferation of goblet cells in the airway, and fibrous thickening of the subepithelial layer, and remarkable increases in expression of Th2 cytokines and eosinophil-related cytokine and chemokine expression in bronchoalveolar lavage fluid. In the in vitro study using BMDM from wild-type, TLR2-/-, and TLR4-/- mice, the TLR-signaling pathway for cytokine production caused by B. adusta was predominantly TLR2 rather than TLR4. H-ASD increased the expression of NF-B and cytokine production by B. adusta in BMDM from ICR mice. The results suggest that co-exposure to H-ASD and B. adusta caused aggravated lung eosinophilia via remarkable increases of pro-inflammatory mediators. The aggravation of inflammation may be related, at least in part, to the activation of the TLR2-NF-B signaling pathway in antigen presenting cells by H-ASD. (c) 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 93-105, 2016.
  • Selective recovery of indium from lead-smelting dust, Hikaru Sawai, Ismail M. M. Rahman, Yoshinori Tsukagoshi, Tomoya Wakabayashi, Teruya Maki, Satoshi Mizutani, Hiroshi Hasegawa, CHEMICAL ENGINEERING JOURNAL, CHEMICAL ENGINEERING JOURNAL, 277, 219 - 228, Oct. 2015 , Refereed
    Summary:Non-ferrous smelting dust, especially lead-smelting dust (LSD), contains percent levels of indium and thus constitutes a novel indium resource. The main difficulty in recovering indium from LSD is the coexisting presence of lead and zinc. In this study, a unique indium separation process was designed, combining techniques that involve washing with a chelant, leaching with acid and precipitation as hydroxide. The majority of the Pb in the LSD was selectively separated during chelant-assisted washing with ethylenediaminedisuccinate (EDDS), while the residual Pb was diminished through an acid leaching treatment with a mixed solution of sulfuric acid and hydrochloric acid. The chelant washing step also ensures a decrease in the raw LSD weight at a ratio of approximately 82% due to the removal of lead and counterions such as sulfate, and the washing step also minimizes the consumption of corrosive acids in the subsequent step. Selective indium separation from LSD is further complicated by the similarity of the behavior of zinc during the acid leaching step. Therefore, hydroxide precipitation at pH 5 has been introduced as the final step, ensuring the maintenance of zinc as a soluble species in the supernatant and the selective separation of indium (similar to 88%) as a hydroxide precipitate. (C) 2015 Elsevier B.V. All rights reserved.
  • Vertical distribution of airborne bacterial communities in an Asian-dust downwind area, Noto Peninsula, Teruya Maki, Kazutaka Hara, Fumihisa Kobayashi, Yasunori Kurosaki, Makiko Kakikawa, Atsushi Matsuki, Bin Chen, Guangyu Shi, Hiroshi Hasegawa, Yasunobu Iwasaka, ATMOSPHERIC ENVIRONMENT, ATMOSPHERIC ENVIRONMENT, 119, 282 - 293, Oct. 2015 , Refereed
    Summary:Bacterial populations transported from ground environments to the atmosphere get dispersed throughout downwind areas and can influence ecosystem dynamics, human health, and climate change. However, the vertical bacterial distribution in the free troposphere was rarely investigated in detail. We collected aerosols at altitudes of 3000 m, 1000 m, and 10 m over the Noto Peninsula, Japan, where the westerly winds carry aerosols from continental and marine areas. During the sampling period on March 10, 2012, the air mass at 3000 m was transported from the Chinese desert region by the westerly winds, and a boundary layer was formed below 2000 m. Pyrosequencing targeting 16S rRNA genes (16S rDNA) revealed that the bacterial community at 3000 m was predominantly composed of terrestrial bacteria, such as Bacillus and Actinobacterium species. In contrast, those at 1000 m and 10 m included marine bacteria belonging to the classes Cyanobacteria and Alphaproteobacteria. The entire 16S rDNA sequences in the clone libraries were identical to those of the terrestrial and marine bacterial species, which originated from the Chinese desert region and the Sea of Japan, respectively. The origins of air masses and meteorological conditions contribute to vertical variations in the bacterial communities in downwind atmosphere. (C) 2015 Elsevier Ltd. All rights reserved.
  • Bioprocess of Kosa bioaerosols: Effect of ultraviolet radiation on airborne bacteria within Kosa (Asian dust), Fumihisa Kobayashi, Teruya Maki, Makiko Kakikawa, Maromu Yamada, Findya Puspitasari, Yasunobu Iwasaka, JOURNAL OF BIOSCIENCE AND BIOENGINEERING, JOURNAL OF BIOSCIENCE AND BIOENGINEERING, 119(5), 570 - 579, May 2015 , Refereed
    Summary:Kosa (Asian dust) is a well-known weather phenomenon in which aerosols are carried by the westerly winds from inland China to East Asia. Recently, the frequency of this phenomenon and the extent of damage caused have been increasing. The airborne bacteria within Kosa are called Kosa bioaerosols. Kosa bioaerosols have affected ecosystems, human health and agricultural productivity in downwind areas. In order to develop a new and useful bacterial source and to identify the source region of Kosa bioaerosols, sampling, isolation, identification, measurement of ultraviolet (UV) radiation tolerance and experimental simulation of UV radiation conditions were performed during Kosa bioaerosol transportation. We sampled these bioaerosols using a Cessna 404 airplane and a bioaerosol sampler at an altitude of approximately 2900 m over the Noto Peninsula on March 27, 2010. The bioaerosol particles were isolated and identified as Bacillus sp. BASZHR 1001. The results of the UV irradiation experiment showed that the UV radiation tolerance of Kosa bioaerosol bacteria was very high compared with that of a soil bacterium. Moreover, the UV radiation tolerance of Kosa bioaerosol spores was higher than that of soil bacterial spores. This suggested that Kosa bioaerosols are transported across the atmosphere as living spores. Similarly, by the experimental simulation of IN radiation conditions, the limited source region of this Kosa bioaerosol was found to be southern Russia and there was a possibility of transport from the Kosa source area. (C) 2014, The Society for Biotechnology, Japan. All rights reserved.
  • Temporal variations of accumulated cesium in natural soils after an uncharacteristic external exposure, Hikaru Sawai, Ismail M. M. Rahman, Chao Lu, Yoshinori Tsukagoshi, Zinnat A. Begum, Teruya Maki, Hiroshi Hasegawa, MICROCHEMICAL JOURNAL, MICROCHEMICAL JOURNAL, 118, 158 - 165, Jan. 2015 , Refereed
    Summary:The accumulation behaviors and solid phase partitioning patterns of stable cesium, which have been recognized as an indicator of the long-term movement of radioactive cesium (Cs-137 or Cs-134) in ecosystems, were studied in typical and natural soils of Japanese origin, namely, red clay, leaf-mold and andosol soils. The retention and migration of soil-phase cesium have been explained relative to various factors, such as soil organic matter contents, competitive cation concentrations and the adsorption ratio of Cs to the solid phase. Cesium was adsorbed nearly quantitatively in the leaf-mold type soil, and the rate of Cs absorption increased as the particle size decreased in the red clay and andosol soils. The distributions of Cs within the soil solid phases were defined using the selective sequential extraction scheme and were used to explain its relative incorporation in the soil fractions. Solid phase fractionation indicated that nearly half of the total cesium concentrations in the soils were in the 'residual' fraction (representing the metal that was incorporated within the crystalline lattice of the soil and was difficult to extract). These findings are expected to provide information regarding suitable conditions for remediation, immobilization or the recovery of cesium from contaminated soils with excess cesium concentrations. (C) 2014 Elsevier B.V. All rights reserved.
  • The Role of Toll-Like Receptors and Myeloid Differentiation Factor 88 in Bjerkandera adusta-Induced Lung Inflammation, Miao He, Takamichi Ichinose, Yuan Song, Yasuhiro Yoshida, Fumihisa Kobayashi, Teruya Maki, Seiichi Yoshida, Hirohisa Takano, Takayuki Shibamoto, Guifan Sun, INTERNATIONAL ARCHIVES OF ALLERGY AND IMMUNOLOGY, INTERNATIONAL ARCHIVES OF ALLERGY AND IMMUNOLOGY, 168(2), 96 - 106, 2015 , Refereed
    Summary:Background: Recently, a cluster of patients with an intractable allergic fungal cough who were characterized by sensitization to Bjerkandera adusta was reported. In the present study, the role of Toll-like receptors and myeloid differentiation factor 88 (MyD88) in B. adusta-induced lung inflammation was investigated. Methods: Wild-type (WT), TLR2(-/-), TLR4(-/-), and MyD88(-/-) BALB/c mice were intratracheally challenged with B. adusta 4 times at 2-week intervals. Lung pathology, bronchoalveolar lavage fluid (BALF) cytological profiles, and inflammatory mediators in BALF were investigated. Bone marrow-derived macrophages (BMDM) from TLR2(-/-), TLR4(-/-), TLR2/4(-/-), TLR7/9(-/-), MyD88(-/-), and WT C57BL/6J mice were stimulated with B. adusta for 12 h, and inflammatory mediators in the culture medium were measured. Results: B. adusta caused lung inflammation along with Th2 cytokine [interleukin (IL)-5 and IL-13] and eosinophil-related chemokine [eotaxin and monocyte chemotactic protein (MCP-3)] production, an increase in eosinophils in BALF, and eosinophil infiltration in the airways in WT and TLR4(-/-) mice. However, Th2 and eosinophil-related responses in TLR2(-/-) and MyD88(-/-) mice were low or undetectable. The induction of neutrophils and IL-6, IL-12, IL-17A, and MCP-1 in the BALF of MyD88(-/-) mice was attenuated compared to that in WT mice. The induction of IL-6, TNF-alpha, MCP1, and macrophage inflammatory protein-1 alpha was reduced or undetectable in B. adusta-stimulated BMDM from TLR7/9(-/-) and MyD88(-/-) mice compared to WT mice. Conclusions: These results suggest that TLR2 and the adapter protein MyD88 may play an important role in the induction of eosinophils by B. adusta. However, TLR7/9-MyD88 might be important in the induction of neutrophils and the relevant inflammatory mediators, especially IL-17A. (C) 2015 S. Karger AG, Basel
  • Recovery of the Rare Metals from Various Waste Ashes with the Aid of Temperature and Ultrasound Irradiation Using Chelants, Hiroshi Hasegawa, Ismail M. M. Rahman, Yuji Egawa, Hikaru Sawai, Zinnat A. Begum, Teruya Maki, Satoshi Mizutani, WATER AIR AND SOIL POLLUTION, WATER AIR AND SOIL POLLUTION, 225(9), Sep. 2014 , Refereed
    Summary:The incineration fly ash (IFA), molten fly ash (MFA), thermal power plant fly ash (TPP-FA), and nonferrous metal processing plant ash (MMA) have been screened in terms of the following rare-termed metal contents: B, Ce, Co, Dy, Eu, Ga, Gd, Hf, In, Li, Lu, Mn, Nb, Nd, Ni, Pr, Rb, Sb, Se, Sm, Sr, Ta, Tb, Te, Ti, Tm, V, W, Y, and Yb. The pseudo-potential for recycling of the waste ashes, as compared to the cumulative concentration in the crust (mg kg(-1)), was determined as follows: MMA>IFA>MFA>TPP-FA. The comparison with the crude ore contents indicates that the MMA is the best resource for reprocessing. The recovery of the target metals using aminopolycarboxylate chelants (APCs) has been attempted at varying experimental conditions and ultrasound-induced environment. A better APC-induced extraction yield can be achieved at 0.10 mol L-1 concentration of chelant, or if the system temperature was maintained between 60 to 80 degrees C. Nevertheless, the mechanochemical reaction induced by the ultrasound irradiation has been, so far, the better option for rare metal dissolution with chelants as it can be conducted at a minimum chelant concentration (0.01 mol L-1) and at room temperature (25 +/- 0.5 degrees C).
  • Variations in the structure of airborne bacterial communities in a downwind area during an Asian dust (Kosa) event, Teruya Maki, Findya Puspitasari, Kazutaka Hara, Maromu Yamada, Fumihisa Kobayashi, Hiroshi Hasegawa, Yasunobu Iwasaka, SCIENCE OF THE TOTAL ENVIRONMENT, SCIENCE OF THE TOTAL ENVIRONMENT, 488, 75 - 84, Aug. 2014 , Refereed
    Summary:Asian dust (Rosa) events transport airborne microorganisms that significantly impact biological ecosystems, human health, and ice-cloud formation in downwind areas. However, the composition and population dynamics of airborne bacteria have rarely been investigated in downwind areas during Kosa events. In this study, air samplings were sequentially performed at the top of a 10-m high building within the Rosa event arrival area (Kanazawa City, Japan) from May 1 to May 7, 2011, during a Rosa event. The particle concentrations of bacterial cells and mineral particles were ten-fold higher during the Rosa event than on non-Rosa event days. A 16S ribosomal DNA clone library prepared from the air samples primarily contained sequences from three phyla: Cyanobacteria, Firmicutes, and Alphaproteobacteria. The clones from Cyanobacteria were mainly from a marine type of Synechococcus species that was dominant during the first phase of the Rosa event and was continuously detected throughout the Rosa event. The clones from Alphaproteobacteria were mainly detected at the initial and final periods of the Rosa event, and phylogenetic analysis showed that their sequences clustered with those from a marine bacterial clade (the SAR clade) and Sphingomonas spp. During the middle of the Rosa event, the Firmicutes species Bacillus subtilis and Bacillus pumilus were predominant; these species are known to be predominant in the atmosphere above the Chinese desert, which is the source of the dust during Rosa events. The clones obtained after the Rosa event had finished were mainly from Bacillus megaterium, which is thought to originate from local terrestrial areas. Our results suggest that airborne bacterial communities at the ground level in areas affected by Rosa events change their species compositions during a Rosa event toward those containing terrestrial and pelagic bacteria transported from the Sea of Japan and the continental area of China by the Rosa event. (C) 2014 Elsevier B.V. All rights reserved.
  • Distribution of trace element in Japanese red coral Paracorallium japonicum by mu-XRF and sulfur speciation by XANES: Linkage between trace element distribution and growth ring formation, Luan Trong Nguyen, Mohammad Azizur Rahman, Teruya Maki, Yusuke Tamenori, Toshihiro Yoshimura, Atsushi Suzuki, Nozomu Iwasaki, Hiroshi Hasegawa, GEOCHIMICA ET COSMOCHIMICA ACTA, GEOCHIMICA ET COSMOCHIMICA ACTA, 127, 1 - 9, Feb. 2014 , Refereed
    Summary:This study investigated the distribution of magnesium (Mg), phosphorus (P), sulfur (S) and strontium (Sr) using micro Xray fluorescence (mu-XRF), and the speciation of S using X-ray absorption near edge spectroscopy (XANES) along the annual growth rings in the skeleton of Japanese red coral Paracorallium japonicum. The Mg, P and S distribution in mu-XRF mapping images correspond to the dark and light bands along the annual growth rings in microscopic images of the coral skeleton. The mu-XRF mapping data showed a positive correlation (r = 0.6) between P and S distribution in the coral skeleton. A contrasting distribution pattern of S and Mg along the axial skeleton of P. japonicum indicates a weak negative correlation (r = -0.2) between these two elements. The distribution pattern of S, P and Mg in the axial skeleton of P. japonicum reveals linkage between the trace element distribution and the formation of dark/light bands along the annual growth rings. Sulfur and P were distributed in the organic matrix rich dark bands, while Mg was distributed in the light bands of the annual growth rings. XANES analysis showed that inorganic sulfate is the major species of S in the skeleton of P. japonicum with a ratio of 1: 20 for organic and inorganic sulfate. (C) 2013 Elsevier Ltd. All rights reserved.
  • Lung inflammation by fungus, Bjerkandera adusta isolated from Asian sand dust (ASD) aerosol and enhancement of ovalbumin-induced lung eosinophilia by ASD and the fungus in mice, Boying Liu, Takamichi Ichinose, Miao He, Fumihisa Kobayashi, Teruya Maki, Seiichi Yoshida, Yasuhiro Yoshida, Keiichi Arashidani, Hirohisa Takano, Masataka Nishikawa, Guifan Sun, Takayuki Shibamoto, ALLERGY ASTHMA AND CLINICAL IMMUNOLOGY, ALLERGY ASTHMA AND CLINICAL IMMUNOLOGY, 10, Feb. 2014 , Refereed
    Summary:Background: Bjerkandera adusta (B. adusta) is one of the most important etiological fungi associated with chronic cough. However, precise details of the inflammatory response to exposure are not well understood yet. B. adusta was recently identified in Asian sand dust (ASD) aerosol. Therefore, in the present study the exacerbating effects of ASD on B. adusta-induced lung inflammation and B. adusta + ASD on ovalbumin (OVA)-induced murine lung eosinophilia were investigated using experimental mice. Methods: In order to prepare testing samples, B. adusta obtained from ASD aerosol was inactivated by formalin and ASD collected from the atmosphere was heated to remove toxic organic substances (H-ASD). CD-1 mice were instilled intratracheally with 12 different samples prepared with various combinations of B. adusta, H-ASD, and OVA in a normal saline solution. The lung pathology, cytological profiles in bronchoalveolar lavage fluid (BALF), and the levels of inflammatory cytokines/chemokines in BALF were investigated. Results: H-ASD aggravated the lung eosinophilia induced by B. adusta alone, which also aggravated the lung eosinophilia induced by OVA. The mixture of OVA, H-ASD, and B. adusta caused serious fibrous thickening of the subepithelial layer, eosinophil infiltration, and proliferation of goblet cells in the airways along with remarkable increases of IL-13, eotaxin, IL-5, and MCP-3 in BALF. Conclusions: The results of the present study demonstrated that B. adusta isolated from ASD aerosol induces allergic lung diseases. H-ASD enhanced allergic reactions caused by OVA or B. adusta. A mixture of B. adusta, H-ASD, and OVA caused the most remarkable exacerbation to the allergic airway inflammation via remarkable increases of pro-inflammatory mediators.
  • Selective recovery of indium from the etching waste solution of the flat-panel display fabrication process, Hiroshi Hasegawa, Ismail M. M. Rahman, Yoshihiro Umehara, Hikaru Sawai, Teruya Maki, Yoshiaki Furusho, Satoshi Mizutani, MICROCHEMICAL JOURNAL, MICROCHEMICAL JOURNAL, 110, 133 - 139, Sep. 2013 , Refereed
    Summary:The waste byproducts from the indium-consuming fabrication processes are considered as the viable resource for indium due to the unique preference to the element in designing optoelectronic devices. The present work introduces a new technique for the selective recovery of indium from the etching waste, which produced during the patterning of indium tin oxide (ITO) layer on the flat-panel displays. The process includes the application of a solid phase extraction (SPE) assembly, known as molecular recognition technology (MRT) gel, consisting of a metal-selective ligand immobilized to silica gel or polymer substrates. The samples were the real solution of etching waste from the liquid-crystal display fabrication process, and the simulated waste solution prepared using the commercially available etching solution composition containing ethanedioic acid. The retention and the corresponding indium recovery rate (%) were the key characteristics for the appraisal of MRT-SPE types: AnaLig TE 02 (TE 02), AnaLig TE 03, AnaLig TE 07, AnaLig TE 13 and AnaLig PM 02. The other conclusive factors were the influence of ion intensity in solution and the interfering effects from tin, the co-content element in the ITO-formulation. The TE 02 MRT-SPE came across all the requisite aspects for the selective recovery of indium from the etching effluent. The indium retention or recovery with TE 02 MRT-SPE from the real etching waste solution was in the range of 97 to 99% with the relative standard deviation of <4.4%. The separation of the ITO co-element tin from the waste mixture was successively selective, and thereby minimizes the possibility of interference. A three-step elution with 03 mol L-1HNO3, 6 mol L-1 HCl and 1 mol L-1 HCl/10 mmol L-1 EDTA was required to accomplish the sequential selectivity in the process. The indium retention capacity of the TE 02 MRT-SPE was 0.147 mmol g(-1). (C) 2013 Elsevier B.V. All rights reserved.
  • NaCl-amendment assay targeting airborne bacteria in tropospheric bioaerosols transported by westerly wind over Noto Peninsula, Teruya Maki, Fumihisa Kobayashi, Maromu Yamada, Hiroshi Hasegawa, Yasunobu Iwasaka, AEROBIOLOGIA, AEROBIOLOGIA, 29(3), 341 - 354, Sep. 2013 , Refereed
    Summary:Bioaerosol particles including bacteria, fungi, and virus are originated from marine and terrestrial environments. The airborne microorganisms are transported for long distance through the free troposphere and are thought to influence the downwind ecosystems and human life. However, microbial communities in the free troposphere have not been understood in detail because the direct sampling of microbial cells at high altitude requires sophisticated sampling techniques. In this study, for the investigation of microbial species compositions in the free troposphere, air sampling using an aircraft was performed over the Noto Peninsula in Japan, where the tropospheric winds carry aerosol particles from continental areas. Two air samples were collected at 3,000 m on March 27, 2010, when air mass was carried from the Gobi Desert to Japan area. Microorganisms from one air sample grew in culture media containing up to 15 % NaCl, suggesting that halotolerant bacteria maintain their viabilities in the free troposphere. DGGE analysis revealed that the amended cultures were dominated by Bacillus subtilis, and the isolates obtained from the amended cultures were identical to B. subtilis. Furthermore, the 16S rDNA clone library (culture-independent survey) of the other air sample grew was composed of three phylotypes belonging to Firmicutes, Bacteroidetes, and Proteobacteria with the sequences of Firmicutes phylotype corresponding to that of the cultured B. subtilis sequence. Microscopic observation using FISH method indicated that B. subtilis particles occupied 80 % of total eubacterial particles on the mineral particles. The halotolerant bacteria identical to B. subtilis would dominate at high altitudes over Noto Peninsula where the prevailing westerly wind was blowing.
  • Ultrasonic inactivation of Microcystis aeruginosa in the presence of TiO2 particles, Kazuaki Ninomiya, Chiaki Ogino, Shinya Kawabata, Kentaro Kitamura, Teruya Maki, Hiroshi Hasegawa, Nobuaki Shimizu, JOURNAL OF BIOSCIENCE AND BIOENGINEERING, JOURNAL OF BIOSCIENCE AND BIOENGINEERING, 116(2), 214 - 218, Aug. 2013 , Refereed
    Summary:This is the first study to demonstrate that Microcystis aeruginosa, a typical algal bloom-forming cyanobacterium, can be effectively inactivated by ultrasound (US) irradiation in the presence of titanium dioxide (TiO2) particles as a sonocatalyst. When a culture broth of M. aeruginosa was ultrasonically irradiated for 15 min in the presence of 0.5 g/mL of TiO2 particles 2 mm in diameter, the cell survival ratio was 0.13, which was significantly lower than that in the case of US irradiation alone (0.87). Moreover, regrowth of M. aeruginosa in the culture was also inhibited for 10 days following ultrasonic disinfection in the presence of TiO2 particles for 15 min. (c) 2013, The Society for Biotechnology, Japan. All rights reserved.
  • Assessment of composition and origin of airborne bacteria in the free troposphere over Japan, Teruya Maki, Makiko Kakikawa, Fumihisa Kobayashi, Maromu Yamada, Atsushi Matsuki, Hiroshi Hasegawa, Yasunobu Iwasaka, ATMOSPHERIC ENVIRONMENT, ATMOSPHERIC ENVIRONMENT, 74, 73 - 82, Aug. 2013 , Refereed
    Summary:Long-range transport of airborne microorganisms through the free troposphere significantly impacts biological ecosystems, human life, and atmospheric processes in downwind areas. However, microbial communities in the free troposphere have rarely been investigated because the direct collection of microbial cells at high altitudes requires sophisticated sampling techniques. In this study, tropospheric air sampling was performed using a balloon and an aircraft at 800 m and 3000 m, respectively, over the Noto Peninsula in Japan (37.5 degrees N, 137.4 degrees E) where free tropospheric winds carry aerosols from continental areas. The air samples were collected during four different sampling periods when air masses came from desert regions of Asian continent (west samples) and from Siberia of Russia North Asia (north samples). The west samples contained higher levels of aerosols, and bacteria from the west samples grew in culture media containing up to 15% NaCl. In contrast, bacteria from the north samples could not be cultured in the same media. All isolates obtained from the NaCl-amended cultures were similar to Bacillus subtilis and classified as Firmicutes. A 16S rDNA clone library prepared from the west samples was mainly composed of one phylotype of Firmicutes that corresponded to the cultured B. subtilis sequence. A clone library prepared from the north samples consisted primarily of two phyla, i.e., Actinobacteria and Proteobacteria, which are known to dominantly inhabit low-temperature environments of North Asia. Our results suggest that airborne bacterial communities at high altitudes include several species that vary by the direction and interaction of free tropospheric winds. (C) 2013 Elsevier Ltd. All rights reserved.
  • Effect of Iron (Fe2+) Concentration in Soil on Arsenic Uptake in Rice Plant (Oryza sativa L.) when Grown with Arsenate [As(V)] and Dimethylarsinate (DMA), M. Azizur Rahman, H. Hasegawa, M. Mamunur Rahman, T. Maki, Richard P. Lim, WATER AIR AND SOIL POLLUTION, WATER AIR AND SOIL POLLUTION, 224(7), art.no.1623, Jul. 2013
    Summary:Being predominant inorganic arsenicals, methylarsenicals also occur in anaerobic paddy soils. Therefore, this study investigated the influence of Fe2+ concentrations and arsenic speciation [arsenate (As(V)) and dimethylarsinate (DMA)] in paddy soils on arsenic uptake in rice plant. Rice seedlings were grown in soil irrigated with a Murashige and Skoog (MS) growth solution containing As(V) or DMA with or without 1.8 mM Fe2+ in excess to the background concentration of total iron (0.03 mM) in the soil. Arsenic concentration in rice roots increased initially and then decreased gradually when the seedlings were grown with excess Fe2+ and As(V). In contrast, arsenic concentration in the roots increased steadily (P<0.01) when the seedlings were grown without excess Fe2+ and As(V). When the form of the arsenic was DMA, total arsenic (tAs) concentration in rice roots increased gradually (P<0.01) and was not affected by the addition of excess Fe2+ in the soil. When rice seedlings were grown with As(V), tAs concentration in rice roots and shoots increased steadily (P<0.01) for gradual increase of Fe2+ concentrations in soil. However, tAs concentration in roots and shoots was independent of Fe2+ concentrations in soil when the form of arsenic was DMA. The tAs concentrations in rice shoots also increased significantly (P<0.01) with increasing exposure time for both As(V) and DMA. Thus, Fe2+ concentrations in soil affect arsenic uptake in rice plant depending on the speciation of arsenic.
  • Decontamination of spent iron-oxide coated sand from filters used in arsenic removal, Ismail M. M. Rahman, Zinnat A. Begum, Hikaru Sawai, Teruya Maki, Hiroshi Hasegawa, CHEMOSPHERE, CHEMOSPHERE, 92(2), 196 - 200, Jun. 2013 , Refereed
    Summary:Sand filters devised with iron-rich adsorbents are extensively promoted and deployed in the arsenic-prone south and south-east Asian countries (e.g., Bangladesh). The approach offers superior performance in removing arsenic while the spent sludge from the sand filters is an issue of concern due to the possibility of toxic releases after being discarded. In this work, a new technique is proposed for the treatment of spent iron-oxide coated sand (IOCS) from filters used in arsenic removal. Chelant-washing of the arsenic-loaded IOCS is combined with the solid phase extraction treatment to accomplish the objective. The unique point of the proposed process is the cost-effective scheme, which includes the option of recycling of the washing solvent beside the decontamination of the spent arsenic-rich sludge. (C) 2013 Elsevier Ltd. All rights reserved.
  • Chelant-induced reclamation of indium from the spent liquid crystal display panels with the aid of microwave irradiation, Hiroshi Hasegawa, Ismail M. M. Rahman, Yuji Egawa, Hikaru Sawai, Zinnat A. Begum, Teruya Maki, Satoshi Mizutani, JOURNAL OF HAZARDOUS MATERIALS, JOURNAL OF HAZARDOUS MATERIALS, 254, 10 - 17, Jun. 2013 , Refereed
    Summary:Indium is a rare metal that is mostly consumed as indium tin oxide (ITO) in the fabrication process of liquid crystal display (LCD) panels. The spent LCD panels, termed as LCD-waste hereafter, is an increasing contributor of electronic waste burden worldwide and can be an impending secondary source of indium. The present work reports a new technique for the reclamation of indium from the unground LCD-waste using aminopolycarboxylate chelants (APCs) as the solvent in a hyperbaric environment and at a high-temperature. Microwave irradiation was used to create the desired system conditions, and a substantial abstraction of indium (>= 80%) from the LCD-waste with the APCs (EDTA or NTA) was attained in the acidic pH region (up to pH 5) at the temperature of >= 120 degrees C and the pressure of similar to 50 bar. The unique point of the reported process is the almost quantitative recovery of indium from the LCD-waste that ensured via the combination of the reaction facilitatory effect of microwave exposure and the metal extraction capability of APCs. A method for the selective isolation of indium from the extractant solution and recycle of the chelant in solution is also described. (C) 2013 Elsevier B.V. All rights reserved.
  • A silica gel-bound macrocycle system for the selective separation of toxic cadmium from metal-affluent aqueous matrix, Hiroshi Hasegawa, Ismail M. M. Rahman, Zinnat A. Begum, Yoshihiro Umehara, Teruya Maki, Yoshiaki Furusho, Satoshi Mizutani, CENTRAL EUROPEAN JOURNAL OF CHEMISTRY, CENTRAL EUROPEAN JOURNAL OF CHEMISTRY, 11(3), 341 - 347, Mar. 2013 , Refereed
    Summary:Selective separation of cadmium(II) on a macrocycle immobilized solid phase extraction (SPE) system namely AnaLig Cd-01, and commonly known as molecular recognition technology (MRT) gel, have been examined. The MRT-SPE able to retain the cadmium from the metal-affluent aqueous matrix at the pH range of 2 to 8, and the captured species can be recovered via elution with 1 and 6 M HNO3. Besides the effects of solution pH and eluent concentration, the impacts of sample loading flow rates and coexisting matrix ions were also investigated and optimized. The Cd(II) retention capacity of the MRT-SPE was 0.26 mmol g-1, and it can be reused for more than 100 loading and elution cycles. The Cd(II) recovery attained from the metal-spiked natural waters was satisfactory (95.3-98.1%). However, the Cd(II) retention ability of the MRT-SPE was significantly decreased when excess of chelant remain in the aqueous waste matrix.
  • Growth characteristics and growth rate estimation of Japanese precious corals, Nguyen Trong Luan, M. Azizur Rahman, Teruya Maki, Nozumu Iwasaki, Hiroshi Hasegawa, JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY, JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY, 441, 117 - 125, Mar. 2013 , Refereed
    Summary:The petrographic method has been a popular technique for estimating the ages and growth rates of corals based on growth ring density in their axial skeleton. The organic matrix staining (OMS) method, a modified method of petrographic method, has also been used for measuring age and growth rate of the Mediterranean red coral (Corallium rubrum) by staining the organic matrix (OM) in the calcite skeleton. Since the OMS method is based on the concentration of OM in the coral skeleton, this method may not be suitable for coral species with low OM content. In the presnt study, growth characteristics and growth rates of three Japanese precious corals (JPCs; Paracorallium japonicum, Corallium elatius and Corallium konojoi) were determined based on the principles of the petrographic method using a high resolution VHX-1000 digital microscope, termed as VIX-1000 hereafter, without staining the OM in the axial skeleton. Compared to the OM-stained cross-sections (slabs), growth rings in un-stained slabs of the Japanese red coral (P. japonicum) were more clearly visible with the VHX-1000. This may be due to low concentration of OM in the coral skeleton. Growth rate of JPCs differ significantly depending on coral species, habitat, and environmental conditions. Diametric and linear growth rates of the Japanese red coral (P. japonicum) were slower (0.20 +/- 0.08-027 +/- 0.01 and 2.22 +/- 0.82-6.66 +/- 5.52 mm yr(-1), respectively) than the Japanese pink (C elatius; 0.30 +/- 0.04 and 2.76 +/- 2.09 mm yr(-1), respectively) and white (C konojoi; 0.44 +/- 0.04 and 7.60 +/- 0.75 mm yr(-1), respectively) corals. In addition, the diametric growth rate of the Japanese red coral (P. japonicum) is slower (0.24 +/- 0.05-0.44 +/- 0.04 mm yr(-1)) than the Mediterranean red coral (C rubrum; 0.20-0.62 +/- 0.19 mm yr(-1)). (C) 2013 Elsevier B.V. All rights reserved.
  • Effect of Extraction Variables on the Biodegradable Chelant-Assisted Removal of Toxic Metals from Artificially Contaminated European Reference Soils, Zinnat A. Begum, Ismail M. M. Rahman, Hikaru Sawai, Satoshi Mizutani, Teruya Maki, Hiroshi Hasegawa, WATER AIR AND SOIL POLLUTION, WATER AIR AND SOIL POLLUTION, 224(3), Mar. 2013 , Refereed
    Summary:Development of aminopolycarboxylate chelants (APCs) having enhanced biodegradability is gaining increasing focus to replace the EDTA and its homologs with those used widely for the ex situ treatment of contaminated soils and are potential eco-threats. The paper reports the chelant-assisted extraction of the toxic metals (Cd, Cu, Pb, and Zn) from the metal-spiked European reference soils (Eurosoil 1 and Eurosoil 4) using biodegradable APCs, namely EDDS, GLDA, and HIDS. The effects of chelant-to-metal molar ratio, solution pH, and metal/chelant stability constants were evaluated, and compared with that of EDTA. The selectivity aptitude of the biodegradable chelants towards the toxic metals was assumed from the speciation calculations, and a proportionate correlation was observed at neutral pH. Pre- and post-extractive solid phase distributions of the target metals were defined using the sequential extraction procedure and dissolution of metals from the theoretically immobilized fraction was witnessed. The effect of competing species (Al, Ca, Fe, Mg, and Mn) concentrations was proven to be minimized with an excess of chelant in solution. The highlight of the outcomes is the superior decontamination ability of GLDA, a biodegradable APC, at minimum chelant concentration in solution and applicability at a wide range of pH environments.
  • Selective separation of Tri- and pentavalent arsenic in aqueous matrix with a macrocycle-immobilized solid-phase extraction system, Ismail M. M. Rahman, Zinnat A. Begum, Yoshiaki Furusho, Satoshi Mizutani, Teruya Maki, Hiroshi Hasegawa, Water, Air, and Soil Pollution, Water, Air, and Soil Pollution, 224(5), 2013 , Refereed
    Summary:A simple flow-based method was developed for the selective separation of arsenic species (+3 and +5) using a macrocycle-immobilized solid phase extraction (SPE) system, commonly known as molecular recognition technology (MRT) gel. Arsenic species in solution or in the eluent were subsequently quantified with graphite furnace atomic absorption spectrometry. The separation behaviors of As(III) and As(V) on MRT-SPE were investigated. It was found that As(V) can be selectively collected on the SPE system within the range of pH 4 to 9, while As(III) was passed through the MRT-SPE. The retention capacity of the MRT-SPE material for As(V) was found to be 0.25 ± 0.04 mmol g -1. The detection limit of the method for As(V) was 0.06 μg L -1, and the relative standard deviation was 2.9 % (n = 10, C = 1 μmol L-1). Interference from the matrix ions was studied. In order to validate the developed method, certified reference materials of effluent wastewater and groundwater samples were analyzed, and the determined values were in good agreement with the certified values. The proposed method was successfully applied to the speciation analysis of tri- and pentavalent arsenic in natural water samples showing satisfactory recoveries (≥ 98.7 %). © 2013 Springer Science+Business Media Dordrecht.
  • Analysis of airborne-bacterial compositions using 16S rDNA clone library technique, Teruya Maki, Rie Fukushima, Fumihisa Kobayashi, Maromu Yamada, Hiroshi Hasegawa, Yasunobu Iwasaka, Bunseki Kagaku, Bunseki Kagaku, 62(12), 1095 - 1104, 2013 , Refereed
    Summary:Microbial communities transported by Asian desert dust (KOSA) events have attracted much attention as bioaerosols, because the transported microorganisms are thought to influence biological ecosystems, and human life as well as atmospheric processes in downwind areas. However, the microbial dynamics in Japan during a KOSA dust event are unclear. In this study, sequential air sampling was performed on the top of a building (10 m altitude) within the KOSA arrival area (Kanazawa City, Japan: 36.6°N, 136.7°E) from May 1 to May 7, 2013, when a dust event occurred. A 16S rDNA clone library prepared from air samples mainly belonged to three phyla, such as Firmicutes, Cyanobacteria, and Alpha-proteobacteria. Some clones of Firmicutes appeared specifically during the midst of a dust event, and consisted primarily of Bacillus subtilis and B. pumilus, which are known to dominantly inhabit atmospheric area in the KOSA source area (Chinese desert). The clones belonging to Cyanobacteria and Alphaproteobacteria were mainly detected at the initial and last periods of dust events they are relatives to marine bacterial species. Our results suggest that airborne bacterial communities on the surface of ground during a dust event are composed of terrestrial and pelagic bacterial populations, and that the dust event influences the dynamics of airborne bacterial communities on the ground surface of a downwind area. © 2013 The Japan Society for Analytical Chemistry.
  • Recovery of indium from end-of-life liquid-crystal display panels using aminopolycarboxylate chelants with the aid of mechanochemical treatment, Hiroshi Hasegawa, Ismail M. M. Rahman, Yuji Egawa, Hikaru Sawai, Zinnat A. Begum, Teruya Maki, Satoshi Mizutani, MICROCHEMICAL JOURNAL, MICROCHEMICAL JOURNAL, 106, 289 - 294, Jan. 2013 , Refereed
    Summary:The metal indium termed as 'rare' in recent days due to its increasing demand in the formulations of electronic and energy-related gadgets and scarce supply resources. Hence, the attempts to recover indium from the secondary resources, such as recycling of the indium abundant waste materials, received increasing research focus. The major indium consumption happens in the form of indium tin oxide (ITO) that used for the fabrication of liquid-crystal displays (LCD). The end-of-life LCD screens, termed as ITO-glass hereafter, are an emerging contributor to the global e-waste load and can be an impending secondary source of indium. The present work introduces a new technique for the treatment of waste ITO-glass using aminopolycarboxylate chelants (APCs) in combination with a mechanochemical treatment process. APCs are capable of forming stable complexes with the indium deposited on the ITO-glass, whereas the rate of recovery was not substantial. The mechanochemical treatment induces the destruction of crystalline structure with which the ITO fragments are attached and facilitate the increased indium dissolution with the chelants. The increase was more prominent followed by a decrease in the cumulative processing time from 24 to 6 h when the vitrified ITO-glass was simultaneously crushed and washed with the chelants. The extraction of indium was better at the acidic pH condition, and it was further intensified when the operating temperature was raised to >= 120 degrees C. (C) 2012 Elsevier B.V. All rights reserved.
  • Formation and Stability of Binary Complexes of Divalent Ecotoxic Ions (Ni, Cu, Zn, Cd, Pb) with Biodegradable Aminopolycarboxylate Chelants (DL-2-(2-Carboxymethyl)Nitrilotriacetic Acid, GLDA, and 3-Hydroxy-2,2 '-Iminodisuccinic Acid, HIDS) in Aqueous Solutions, Zinnat A. Begum, Ismail M. M. Rahman, Yousuke Tate, Yuji Egawa, Teruya Maki, Hiroshi Hasegawa, JOURNAL OF SOLUTION CHEMISTRY, JOURNAL OF SOLUTION CHEMISTRY, 41(10), 1713 - 1728, Nov. 2012 , Refereed
    Summary:The protonation and complex formation equilibria of two biodegradable aminopolycarboxylate chelants {dl-2-(2-carboxymethyl)nitrilotriacetic acid (GLDA) and 3-hydroxy-2,2'-iminodisuccinic acid (HIDS)} with Ni2+, Cu2+, Zn2+, Cd2+ and Pb2+ ions were investigated using the potentiometric method at a constant ionic strength of I = 0.10 mol center dot dm(-3) (KCl) in aqueous solutions at 25 +/- A 0.1 A degrees C. The stability constants of the proton-chelant and metal-chelant species for each metal ion were determined, and the concentration distributions of various complex species in solution were evaluated for each ion. The stability constants (log(10) K (ML)) of the complexes containing Ni2+, Cu2+, Zn2+, Cd2+ and Pb2+ ions followed the identical order of log(10) K (CuL) > log(10) K (NiL) > log(10) K (PbL) > log(10) K (ZnL) > log(10) K (CdL) for either GLDA (13.03 > 12.74 > 11.60 > 11.52 > 10.31) or HIDS (12.63 > 11.30 > 10.21 > 9.76 > 7.58). In each case, the constants obtained for metal-GLDA complexes were larger than the corresponding constants for metal-HIDS complexes. The conditional stability constants (log(10) ) of the metal-chelant complexes containing GLDA and HIDS were calculated in terms of pH, and compared with the stability constants for EDTA and other biodegradable chelants.
  • Stability Constants of Fe(III) and Cr(III) Complexes with DL-2-(2-Carboxymethyl)nitrilotriacetic Acid (GLDA) and 3-Hydroxy-2,2 '-iminodisuccinic acid (HIDS) in Aqueous Solution, Zinnat A. Begum, Ismail M. M. Rahman, Hikaru Sawai, Yousuke Tate, Teruya Maki, Hiroshi Hasegawa, JOURNAL OF CHEMICAL AND ENGINEERING DATA, JOURNAL OF CHEMICAL AND ENGINEERING DATA, 57(10), 2723 - 2732, Oct. 2012 , Refereed
    Summary:The complex formation equilibria of Cr3+ and Fe3+ ions in aqueous solution with two biodegradable amino-polycarboxylate chelants (DL-2-(2-carboxymethyl)nitrilotriacetic acid (GLDA) and 3-hydroxy-2,2'-iminodisuccinic acid (HIDS)) were investigated. The potentiometric data obtained at the constant ionic strengths (I) of (0.1 and 1.0) mol.dm(-3) KCl and at (25 +/- 0.1) degrees C was processed with the aid of the computer program HYPERQUAD 2008. The formation constants of the proton-chelant and metal-chelant (log K-ML) species (M = Fe3+ or Cr3+; L = GLDA or HIDS) were determined, and the concentration distributions of complex species in solution were evaluated for both metal ions. In various pH conditions, the interaction between the chelants (L = GLDA or HIDS) and the metal ions (M = Fe3+ or Cr3+) leads to the formation of different complexes formulated as MH2L+, MHL, ML-, M(OH)L2-, and M(OH)(2)L3-. The log K-ML values at I = 0.1 mol.dm(-3) KCl (T = (25 +/- 0.1) degrees C) were 15.27 (log KFe-GLDA), 14.96 (log KFe-HIDS), 13.77 (log KCr-GLDA), 12.67 (log KCr-HIDS), and at I = 1.0 mol.dm(-3) KCl (T = (25 +/- 0.1) degrees C) were 14.79 (log KFe-GLDA), 14,34 (log KFe-HIDS)) 12.90 (log KCr-GLDA), 12.09 (log KCr-HIDS). The e conditional stability constants (log K'(ML)) of the ML complexes were calculated in terms of pH in the range of 2 to 12 and compared with the same for EDTA and other biodegradable chelants (NTA and EDDS).
  • Significance of the concentration of chelating ligands on Fe3+-solubility, bioavailability, and uptake in rice plant, Hiroshi Hasegawa, M. Mamunur Rahman, Kouta Kadohashi, Yui Takasugi, Yousuke Tate, Teruya Maki, M. Azizur Rahman, PLANT PHYSIOLOGY AND BIOCHEMISTRY, PLANT PHYSIOLOGY AND BIOCHEMISTRY, 58, 205 - 211, Sep. 2012 , Refereed
    Summary:Present study investigated the significance of the concentration of chelating ligand on Fe3+-solubility in growth medium and its influence on Fe bioavailability and uptake in rice plant. Rice seedlings were grown in modified Murashige and Skoog (MS) hydroponic growth medium with moderate (250 mu M) and high (500 mu M) concentrations of ethylenediaminetetraacetate (EDTA) and hydroxyiminodisuccinate (HIDS) under sterile and non-sterile conditions. Concentrations of soluble Fe in the growth medium increased with increasing ligand concentrations, and the growth of rice seedlings was higher at moderate ligand concentration than at control (without chelant) and high ligand concentration. This explains the relationship between Fe solubility and bioavailability in the growth medium, and its effect on Fe uptake in rice plant. Fe exists in the growth medium predominantly as particulate (insoluble) forms at low ligand concentration, and as soluble [Fe(OH)(2+), Fe(OH)(2)(+), Fe-L complex] and apparently soluble (colloidal) forms at moderate ligand concentration. At high ligand concentration, most of the Fe3+ in the growth medium forms soluble Fe L complex, however, the bioavailability of Fe from Fe L complex decreased due to lopsided complex formation equilibrium reaction (CFER) between Fe and the ligands. Also, Fe is solubilized forming stable and soluble Fe-L complex, which is then detached as less stable, but soluble and bioavailable substance(s) after (time-dependent) biodegradation. Therefore- i) ligand concentration and stability constant of Fe-L complex (KFe-L) influence Fe bioavailability and uptake in rice plant, and ii) the biodegradable ligands (e.g., HIDS) would be more effective Fe fertilizer than the environmentally persistent and less biodegradable ligands (e.g., EDTA). (C) 2012 Elsevier Masson SAS. All rights reserved.
  • Remediation of toxic metal contaminated soil by washing with biodegradable aminopolycarboxylate chelants, Zinnat A. Begum, Ismail M. M. Rahman, Yousuke Tate, Hikaru Sawai, Teruya Maki, Hiroshi Hasegawa, CHEMOSPHERE, CHEMOSPHERE, 87(10), 1161 - 1170, Jun. 2012 , Refereed
    Summary:Ex situ soil washing with synthetic extractants such as, aminopolycarboxylate chelants (APCs) is a viable treatment alternative for metal-contaminated site remediation. EDTA and its homologs are widely used among the APCs in the ex situ soil washing processes. These APCs are merely biodegradable and highly persistent in the aquatic environments leading to the post-use toxic effects. Therefore, an increasing interest is focused on the development and use of the eco-friendly APCs having better biodegradability and less environmental toxicity. The paper deals with the results from the lab-scale washing treatments of a real sample of metal-contaminated soil for the removal of the ecotoxic metal ions (Cd, Cu, Ni, Pb, and Zn) using five biodegradable APCs, namely [S,S]-ethylenediaminedisuccinic acid, imminodisuccinic acid, methylglycinediacetic acid. DL-2-(2-carboxymethyl) nitrilotriacetic acid (GLDA), and 3-hydroxy-2,2'-iminodisuccinic acid. The performance of those biodegradable APCs was evaluated for their interaction with the soil mineral constituents in terms of the solution pH and metal-chelant stability constants, and compared with that of EDTA. Speciation calculations were performed to identify the optimal conditions for the washing process in terms of the metal-chelant interactions as well as to understand the selectivity in the separation ability of the biodegradable chelants towards the metal ions. A linear relationship between the metal extraction capacity of the individual chelants towards each of the metal ions from the soil matrix and metal-chelant conditional stability constants for a solution pH greater than 6 was observed. Additional considerations were derived from the behavior of the major potentially interfering cations (Al, Ca, Fe, Mg, and Mn), and it was hypothesized that use of an excess of chelant may minimize the possible competition effects during the single-step washing treatments. Sequential extraction procedure was used to determine the metal distribution in the soil before and after the extractive decontamination using biodegradable APCs, and the capability of the APCs in removing the metal ions even from the theoretically immobilized fraction of the contaminated soil was observed. GLDA appeared to possess the greatest potential to decontaminate the soil through ex situ washing treatment compared to the other biodegradable chelants used in the study. (C) 2012 Elsevier Ltd. All rights reserved.
  • Biodegradation of phenol in seawater using bacteria isolated from the intestinal contents of marine creatures, Fumihisa Kobayashi, Teruya Maki, Yoshitoshi Nakamura, INTERNATIONAL BIODETERIORATION & BIODEGRADATION, INTERNATIONAL BIODETERIORATION & BIODEGRADATION, 69, 113 - 118, Apr. 2012 , Refereed
    Summary:For the bioremediation of pollutants in seawater, the degradation of phenol using novel marine bacteria isolated from the intestinal contents of marine creatures was investigated. Twenty samples of marine creatures were collected, and bacteria in their intestinal contents were incubated in an artificial seawater agar medium containing phenol. Two colonies (EBR01 and EBR02) were observed from Dendrodoris fumata, and one colony (EBR04) was observed from Suggrundus meerdervoortii. Analysis of the bacterial properties, gene sequencing, similarities, and phylogenetic characteristics showed that strains EBR01 and EBR02 were Acinetobacter species and strain EBR04 was Cobetia marina. Acinetobacter spp. EBR01, EBR02, and C. marina EBR04 degraded almost 100 mg l(-1) phenol in seawater. The maximum phenol degradation rate using Acinetobacter sp. EBR01 was the highest value, and it was 2.7-fold higher than that using activated sludge. (C) 2011 Elsevier Ltd. All rights reserved.
  • Trace elements in Corallium spp. as indicators for origin and habitat, Hiroshi Hasegawa, M. Azizur Rahman, Nguyen Trong Luan, Teruya Maki, Nozumu Iwasaki, JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY, JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY, 414, 1 - 5, Mar. 2012 , Refereed
    Summary:Precious corals have been commercially exploited for many centuries around the world. The skeletons of these corals consist of calcium carbonate, and have been used as amulets or gemstones since ancient times. Different Corallium species of Coralidae family (e.g.. Corallium rubrum, Corallium elatus, Corallium konojoi, and Paracorellium japonicum) were collected from different locations of the Mediterranean Sea (off Italy) and Pacific Ocean (off Japan and off Midway Island), and trace elements in their skeletons were analyzed. Results show that trace element concentrations in the skeletons of Corallium spp. were attributable to their habitat and origin. In particular, Mg/Ca and Ba/Ca ratios in the skeletons of Corallium spp. from the Mediterranean Sea and Japanese and the Midway Islands' waters were found to be habitat-specific. This study also reveals that trace elements in the skeletons can be used as ecological indicator of the coral's origin, and are expected to play an important part in the cultural study and sustainable management of precious corals. Findings of this study will also be of great relevance to the coral industry to authenticate and identify the habitat and origin of the corals. (C) 2012 Elsevier B.V. All rights reserved.
  • Selective separation of some ecotoxic transition metal ions from aqueous solutions using immobilized macrocyclic material containing solid phase extraction system (vol 9, pg 1019, 2011), Ismail M. M. Rahman, Yoshiaki Furusho, Zinnat A. Begum, Akhmad Sabarudin, Shoji Motomizu, Teruya Maki, Hiroshi Hasegawa, CENTRAL EUROPEAN JOURNAL OF CHEMISTRY, CENTRAL EUROPEAN JOURNAL OF CHEMISTRY, 10(1), 277 - 277, Feb. 2012 , Refereed
    Summary:The original version of the article was published in Cent. Eur. J. Chem. 9(6) (2011), pp 1019-1026. Unfortunately, the original version of this article contains mistakes in the body of Fig. 1. Here we display the corrected version of the Fig. 1.
  • Selective separation of some ecotoxic transition metal ions from aqueous solutions using immobilized macrocyclic material containing solid phase extraction system, Ismail M. M. Rahman, Yoshiaki Furusho, Zinnat A. Begum, Akhmad Sabarudin, Shoji Motomizu, Teruya Maki, Hiroshi Hasegawa, CENTRAL EUROPEAN JOURNAL OF CHEMISTRY, CENTRAL EUROPEAN JOURNAL OF CHEMISTRY, 9(6), 1019 - 1026, Dec. 2011 , Refereed
    Summary:A simple flow-based method was developed for the simultaneous separation of certain transition metal ions (Co, Ni, Cu, Zn, Cd) from aqueous systems, which ions show ecotoxic effects when present at elevated concentrations. A silica-gel-bonded macrocycle system, commonly known as molecular recognition technology (MRT) gel, was used for solid phase extraction (SPE) of the target analytes. The collection behavior of the MRT-SPE system was studied based on pH. Fortified deionized water samples containing 250 mu g L(-1) of each of the elements were treated at the flow rate of 1 mL min(-1). The collected analytes were then eluted by 3 M HNO(3) and analyzed using inductively coupled plasma spectrometry. Detection limits of the proposed technique were in the range of 0.004-0.040 mu g L(-1) for the studied metal ions. The validity of this separation technique was checked with spiked 'real' water samples, which produced satisfactory recoveries of 96-102%. The non-destructive nature and highly selective ion-extraction capability of the SPE material are the most important aspects of the proposed method and they are the main focus of this paper.
  • Characterization of halotolerant and oligotrophic bacterial communities in Asian desert dust (KOSA) bioaerosol accumulated in layers of snow on Mount Tateyama, Central Japan, Teruya Maki, Kazuma Aoki, Fumihisa Kobayashi, Makiko Kakikawa, Yutaka Tobo, Atsushi Matsuki, Hiroshi Hasegawa, Yasunobu Iwasaka, AEROBIOLOGIA, AEROBIOLOGIA, 27(4), 277 - 290, Dec. 2011 , Refereed
    Summary:Microbial particles transported by Asian desert dust (KOSA) possibly impact ecosystems and human health in downwind environments and are commonly called "bioaerosols." The microbial communities associated with KOSA mineral particles (KOSA bioaerosol), which were collected from the snow cover on Mt. Tateyama, were investigated by means of a culture-amendment technique combined with denaturing gradient gel electrophoresis (DGGE) analysis using 16S rRNA genes. After the stratigraphy of the snow layer formed on the walls of a snow pit on Mt. Tateyama, samples were collected from 2 layers, which included KOSA particles and one which did not. The snow samples with KOSA particles indicated microbial growth in the 10 0 and 10(-1) dilution media and in the medium with NaCl below 10%, while the snow sample without KOSA particles showed no microbial growth in the culture media. The PCR-DGGE analysis revealed that the bacterial compositions in the snow samples including KOSA mineral particles were mainly composed of the members of the phyla Actinobacteria, Firmicutus, and Proteobacteria. In particular, the 2 phylotypes appeared in the microbial cultures were similar to the members of the B. subtilis group, which has been detected in bioaerosol samples collected from the atmosphere over KOSA arrival (Suzu City) and source (Dunhuang City) regions. Presumably, halo-tolerant and oligotrophic bacterial communities are associated with the KOSA particles that descend to the snow cover on Mt. Tateyama.
  • Recovery of toxic metal ions from washing effluent containing excess aminopolycarboxylate chelant in solution, Hiroshi Hasegawa, Ismail M. M. Rahman, Masayoshi Nakano, Zinnat A. Begum, Yuji Egawa, Teruya Maki, Yoshiaki Furusho, Satoshi Mizutani, WATER RESEARCH, WATER RESEARCH, 45(16), 4844 - 4854, Oct. 2011 , Refereed
    Summary:Aminopolycarboxylate chelants (APCs) are extremely useful for a variety of industrial applications, including the treatment of toxic metal-contaminated solid waste materials. Because non-toxic matrix elements compete with toxic metals for the binding sites of APCs, an excess of chelant is commonly added to ensure the adequate sequestration of toxic metal contaminants during waste treatment operations. The major environmental impacts of APCs are related to their ability to solubilize toxic heavy metals. If APCs are not sufficiently eliminated from the effluent, the aqueous transport of metals can occur through the introduction of APCs into the natural environment, increasing the magnitude of associated toxicity. Although several techniques that focus primarily on the degradation of APCs at the pre-release step have been proposed, methods that recycle not only the processed water, but also provide the option to recover and reuse the metals, might be economically feasible, considering the high costs involved due to the chelants used in metal ion sequestration. In this paper, we propose a separation process for the recovery of metals from effluents that contain an excess of APCs. Additionally, the option of recycling the processed water using a solid phase extraction (SPE) system with an ion-selective immobilized macrocyclic material, commonly known as a molecular recognition technology (MRT) gel, is presented. Simulated effluents containing As(V), Cd(II), Cr(III), Pb(II) or Se(IV) in the presence of APCs at molar ratios of 1:50 in H(2)O were studied with a flow rate of 0.2 mL min(-1). The 'captured' ions in the SPE system were quantitatively eluted with HNO(3). The effects of solution pH, metal-chelant stability constants and matrix elements were assessed. Better separation performance for the metals was achieved with the MRT-SPE compared to other SPE materials. Our proposed technique offers the advantage of a non-destructive separation of both metal ions and chelants compared to conventional treatment options for such effluents. (C) 2011 Elsevier Ltd. All rights reserved.
  • Transport of DMAA and MMAA into rice (Oryza sativa L.) roots, M. Azizur Rahman, K. Kadohashi, T. Maki, H. Hasegawa, ENVIRONMENTAL AND EXPERIMENTAL BOTANY, ENVIRONMENTAL AND EXPERIMENTAL BOTANY, 72(1), 41 - 46, Aug. 2011
    Summary:Arsenate (As(V)) transport into plant cells has been well studied. A study on rice (Oryza sativa L) showed that arsenite is transported across the plasma membrane via glycerol transporting channels. Previous studies reported that the dimethylarsinic acid (DMAA) and monomethylarsonic acid (MMAA) uptake in duckweed (Spirodela polyrhiza L) differed from that of As(V), and was unaffected by phosphate (H(2)PO(4)). This article reports the transport mechanisms of DMAA and MMAA in rice roots. Linear regression analysis showed that the DMAA and MMAA uptake in rice roots increased significantly (p <= 0.0002 and <= 0.0001 for DMAA and MMAA, respectively) with the increase of exposure time. Concentration-dependent influx of DMAA and MMAA showed that the uptake data were well described by Michaelis-Menten kinetics. The MMAA influx was higher than that of DMAA. The DMAA and MMAA uptake in rice roots were decreased significantly (p <= 0.0001 and <= 0.0077 for DMAA and MMAA, respectively) with the increase of glycerol concentration indicating that DMAA and MMAA were transported into rice roots using the same mechanisms of glycerol. Glycerol is transported into plant cells by aquaporins, and DMAA and MMAA are transported in a dose-dependent manner of glycerol which reveals that DMAA and MMAA are transported into rice roots through glycerol transporting channels. The DMAA and MMAA concentration in the solution did not affect the inhibition of their uptake rate by glycerol. (C) 2010 Elsevier B.V. All rights reserved.
  • Influence of aggregated particles on biodegradation activities for dimethylarsinic acid (DMA) in Lake Kahokugata, Teruya Maki, Wakana Hirota, Hiroyuki Motojima, Hiroshi Hasegawa, Mohammad Azizur Rahman, CHEMOSPHERE, CHEMOSPHERE, 83(11), 1486 - 1492, Jun. 2011 , Refereed
    Summary:Aquatic arsenic cycles mainly depend on microbial activities that change the arsenic chemical forms and influence human health and organism activities. The microbial aggregates degrading organic matter are significantly related to the turnover between inorganic arsenic and organoarsenic compounds. We investigated the effects of microbial aggregates on organoarsenic mineralization in Lake Kahokugata using lake water samples spiked with dimethylarsinic acid (DMA). The lake water samples converted 1 mu mol L(-1) of DMA to inorganic arsenic for 28 d only under anaerobic and dark conditions in the presence of microbial activities. During the DMA mineralization process, organic aggregates > 5.0 mu m with bacterial colonization increased the densities. When the organic aggregates > 5.0 mu m were eliminated from the lake water samples using filters, the degradation activities were reduced. DMA in the lake water would be mineralized by the microbial aggregates under anaerobic and dark conditions. Moreover, DMA amendment enhanced the degradation activities in the lake water samples, which mineralized 50 mu mol L(-1) of DMA. The DMA-amended aggregates > 5.0 mu m completely degraded 1 mu mol L(-1) of DMA with a shorter incubation time of 7 d. The supplement of KNO(3) and NaHCO(3) to lake water samples also shortened the DMA-degradation period. Presumably, the bacterial aggregates involved in the chemical heterotrophic process would contribute to the DMA-biodegradation process in Lake Kahokugata, which is induced by the DMA amendment. (c) 2011 Elsevier Ltd. All rights reserved.
  • Separation of dissolved iron from the aqueous system with excess ligand, Hiroshi Hasegawa, Ismail M. M. Rahman, Sanae Kinoshita, Teruya Maki, Yoshiaki Furusho, CHEMOSPHERE, CHEMOSPHERE, 82(8), 1161 - 1167, Feb. 2011 , Refereed
    Summary:A new technique for the separation and pre-concentration of dissolved Fe(III) from the ligand-rich aqueous system is proposed. A solid phase extraction (SPE) system with an immobilized macrocyclic material, commonly known as molecular recognition technology (MRT) gel and available commercially, was used. Synthetic Fe(III) solution in aqueous matrices spiked with a 100-fold concentration of EDTA was used. Dissolved iron that was 'captured' by the MRT gel was eluted using hydrochloric acid and subsequently determined by graphite furnace atomic absorption spectrometry. The effect of different variables, such as pH, reagent concentration, flow rate and interfering ions, on the recovery of analyte was investigated. Quantitative maximum separation (similar to 100%) of the dissolved Fe(III) from synthetic aqueous solutions at a natural pH range was observed at a flow rate of 0.2 mL min(-1). The extraction efficiency of the MRT gel is largely unaltered by the coexisting ions commonly found in natural water. When compared with different SPE materials, the separation performance of MRT gel is also much higher. (C) 2010 Elsevier Ltd. All rights reserved.
  • Selective separation of arsenic species from aqueous solutions with immobilized macrocyclic material containing solid phase extraction columns, Ismail M. M. Rahman, Zinnat A. Begum, Masayoshi Nakano, Yoshiaki Furusho, Teruya Maki, Hiroshi Hasegawa, CHEMOSPHERE, CHEMOSPHERE, 82(4), 549 - 556, Jan. 2011 , Refereed
    Summary:A combination of solid phase extraction (SPE) columns was used for selective separation of water-soluble arsenic species: arsenite, arsenate, monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA). The SPE columns, namely AnaLig TE-01 (TE-01), AnaLig AN-01 Si (AN-01) and AnaLig As-01 PA (As-01), contain immobilized macrocyclic material as the sorbent and commonly known as molecular recognition technology (MRT) gel. The retention, extraction and recovery behavior of the MRT gel SPE columns were studied at pH 4-10. Fortified deionized water spiked with 100 mu M of arsenic species were treated at the flow rate of 0.2 mL min(-1). HNO(3) (1.0 and 6.0 M) was used as eluent to recover the retained arsenic species from TE-01 and AN-01 SPE columns. Arsenic species retained in the As-01 column were eluted with HNO(3) (0.1 M) followed by NaOH (2.0 M). Likely interference from the various coexisting ions (Na(+), K(+), Ca(2+), Mg(2+), Cl(-), NO(3)(-), CH(3)COO(-), PO(4)(3-), SO(4)(2-), ClO(4)(-)) (10 mm) were negligible. Quantitative separation of As(III), As(V), MMA and DMA was achieved based on the differences in extraction and recovery behavior of the MRT gel SPE columns with pH for different arsenic species. Complexation between arsenic species and MRT gel is the core phenomenon of the proposed technique as the complexation of MRT gels is expected to be stronger than the resin-based separation processes. MRT gel SPE columns are advantageous as compared with other reported SPE columns in terms of its performance with As(III). Effortless regeneration and unaltered separation performance of the sorbent materials for more than 100 loading and elution cycles are other sturdy characteristics to consider the MRT gel SPE columns for sensitive and selective arsenic species separation. (C) 2010 Elsevier Ltd. All rights reserved.
  • Phylogenetic analysis of atmospheric halotolerant bacterial communities at high altitude in an Asian dust (KOSA) arrival region, Suzu City, Teruya Maki, Shinzi Susuki, Fumihisa Kobayashi, Makiko Kakikawa, Yutaka Tobo, Maromu Yamada, Tomomi Higashi, Atsushi Matsuki, Chunsang Hong, Hiroshi Hasegawa, Yasunobu Iwasaka, SCIENCE OF THE TOTAL ENVIRONMENT, SCIENCE OF THE TOTAL ENVIRONMENT, 408(20), 4556 - 4562, Sep. 2010 , Refereed
    Summary:The microbial communities transported by Asian desert dust (KOSA) events have attracted much attention as bioaerosols because the transported microorganisms are thought to influence the downwind ecosystems in Korea and Japan. However, the atmospheric microbial community has not been investigated at high altitude in the KOSA arrival area. In this study, to estimate the viability and diversity of atmospheric halotolerant bacteria, which are expected to resist to various environmental stresses as well as high salinities, bioaerosol samples were collected at 10 and 600 m above the ground within the KOSA arrival area, Suzu City, Japan, during KOSA events. During the sampling period, the particle numbers at 600 m were higher than those at 10 m, suggesting that large particles of aerosol fall from the high altitude of 600 m to the ground surface. The microorganisms in bioaerosol samples grew in media containing up to 15% NaCl concentrations demonstrating the viability of the halotolerant bacteria in bioaerosol samples. The PCR-DGGE analysis using 16S rDNA revealed that the bacterial species in NaCl-amended cultures were similar to the bacteria detected from the genomic DNA directly extracted from the bioaerosol samples. The 16S rDNA sequences of bacterial communities in bioaerosol samples were classified into 4 phylotypes belonging to the Bacillus cereus or Bacillus subtilis group. The bioaerosol samples collected at 600 m included 2 phylotypes belonging to B. subtilis. and one phylotype among all 4 phylotypes was identical between the samples at 10 and 600 m. In the atmosphere at 600 m, the halotolerant bacterial community was expected to remain viable, and the species composition was expected to include a few species of the genus Bacillus. During this investigation period, these atmospheric bacteria may have been vertically transported to the ground surface, where the long-range KOSA particle transport from China is frequently observed. (C) 2010 Elsevier B.V. All rights reserved.
  • Distributions of Trace Elements in Biogenic Carbonate Minerals of Precious Corals by X-ray Fluorescence Analysis, Hiroshi Hasegawa, Nozomu Iwasaki, Atsushi Suzuki, Teruya Maki, Shinjiro Hayakawa, BUNSEKI KAGAKU, BUNSEKI KAGAKU, 59(6), 521 - 530, Jun. 2010 , Refereed
    Summary:Precious coral is one of the natural resources of which Japan is a major supplier. Since the concentrations of trace elements in the skeletons are less than 1 ppm, it is difficult to determine the behavior of trace elements other than Ca, Mg and Sr using conventional instruments for mapping analysis at a laboratory scale. In this study, the distributions of trace elements in the skeletons of precious corals were analysed with XRF mapping employing synchrotron radiation at a large circular accelerator in SPring-8. Using 37.6 keV X-rays with a beam size of 50 mu m (horizontally) x 50 mu m (vertically), Ba, I, Mo, Sn, Mn, Zn, Cd and Br, as well as the major element of Ca and Sr, were detected in the skeletons. Two-dimensional maps of the trace element distribution showed that those of Ba, I and Mo concentrations form fine granular structure in the skeletons of precious corals, while Ca and Sr are almost homogeneously distributed. As compared with the element composition in the skeletons of Corallium rubrum from the Mediterranean Sea, Corallium japonicum from Japanese waters, and deep sea corals from Ogasawara and Midway Islands, relatively high contents of Cd and Ba were detected in the deep corals, which suggested that Cd and Ba are incorporated in proportion to the concentrations in the surrounding seawater. These elements are expected to be good marker elements for identifying species and harvest areas.
  • Seasonal changes of arsenic speciation in lake waters in relation to eutrophication, H. Hasegawa, M. Azizur Rahman, K. Kitahara, Y. Itaya, T. Maki, K. Ueda, SCIENCE OF THE TOTAL ENVIRONMENT, SCIENCE OF THE TOTAL ENVIRONMENT, 408(7), 1684 - 1690, Mar. 2010
    Summary:In this study, the influence of eutrophication on arsenic speciation in lake waters was investigated. Surface water samples (n = 1-10) were collected from 18 lakes in Japan during July 2007 and February 2008. The lakes were classified into mesotrophic (7 lakes) and eutrophic (11 lakes) based on the total phosphate (T-P) and chlorophyll-a (Chl-a) concentrations in water column. Inorganic, methylated and ultraviolet-labile fractions of arsenic species were determined by combining hydride generation atomic absorption spectrometry with ultraviolet irradiation. Organoarsenicals (mainly methylated and ultraviolet-labile fractions) comprised 30-60% of the total arsenic in most lakes during summer. On the other hand, inorganic arsenic species (As(III + V)) dominates (about 60-85%) during winter. The occurrence of ultraviolet-labile fractions of arsenic was higher in eutrophic lakes than those in mesotrophic lakes in both seasons. The concentration of dimethyl arsenic (DMAA) was high in eutrophic lakes during winter; and in mesotrophic lakes during summer. The results suggest that the conversion of As(III + V) to more complicated organoarsenicals occurred frequently in eutrophic lakes compared to that in mesotrophic lakes, which is thought to be the influence of biological activity in the water column. The distribution of arsenic species were well correlated with phosphate concentrations than those of Chl-a. This might be due to the competitive uptake of As(V) and phosphate by phytoplankton. The organoarsenicals (OrgAs)/As(V) ratio was higher at low phosphate concentration indicating that conversion of As(V) to OrgAs species was more active in phosphate-exhausted lakes with high phytoplankton density. (C) 2009 Elsevier B.V. All rights reserved.
  • Non-destructive separation of metal ions from wastewater containing excess aminopolycarboxylate chelant in solution with an ion-selective immobilized macrocyclic material, Hiroshi Hasegawa, Ismail M. M. Rahman, Sanae Kinoshita, Teruya Maki, Yoshiaki Furusho, CHEMOSPHERE, CHEMOSPHERE, 79(2), 193 - 198, Mar. 2010 , Refereed
    Summary:Although the excellent metal-binding capacities of aminopolycarboxylate chelants (APCs) facilitate their extensive use, pre- and post-toxicity of APCs and their high persistence in aquatic environments evoke concerns. Several treatment techniques with a principal focus on the degradation of APCs at the pre-release step have been proposed. Here, we report a technique for the separation of metal ions from waste solution containing excess APCs using a solid phase extraction system with an ion-selective immobilized macrocyclic material, commonly known as a molecular recognition technology (MRT) gel. Synthetic metal solutions with 100-fold chelant content housed in H(2)O matrices were used as samples. The MRT gel showed a higher recovery rate compared with other SPE materials at 20 degrees C using a flow rate of 0.2 mL min(-1). The effects of solution pH, metal-chelant stability constants and ionic radii were assessed for 32 metals. Compared to the conventional treatment options for such waste solutions, our proposed technique has the advantage of non-destructive separation of both metal ions and chelants. (C) 2010 Elsevier Ltd. All rights reserved.
  • Hydroxyiminodisuccinic acid (HIDS): A novel biodegradable chelating ligand for the increase of iron bioavailability and arsenic phytoextraction, M. Azizur Rahman, H. Hasegawa, K. Kadohashi, T. Maki, K. Ueda, CHEMOSPHERE, CHEMOSPHERE, 77(2), 207 - 213, Sep. 2009
    Summary:The influence of biodegradable chelating ligands on arsenic and iron uptake by hydroponically grown rice seedlings (Oryza sativa L.) was investigated. Even though the growth solution contained sufficient Fe, the growth of rice seedlings gradually decreased up to 76% with the increase of pH of the solution from 7 to 11. Iron forms insoluble ferric hydroxide complexes at neutral or alkaline pH in oxic condition. Chelating ligands produce soluble 'Fe-ligand complex' which assist Fe uptake in plants. The biodegradable chelating ligand hydroxyiminodisuccinic acid (HIDS) was more efficient then those of ethylenediaminetetraacetic acid (EDTA), ethylenediaminedisuccinic acid (EDDS), and iminodisuccinic acid (IDS) in the increase of Fe uptake and growth of rice seedling. A total of 79 +/- 20, 87 +/- 6, 116 +/- 15, and 63 +/- 18 mg dry biomass of rice seedlings were produced with the addition of 0.5 mM of EDDS, EDTA, HIDS, and IDS in the nutrient solution, respectively. The Fe concentrations in rice tissues were 117 +/- 15, 82 +/- 8. 167 +/- 25, and 118 +/- 22 mu mol g(-1) dry weights when 0.25 mM of EDDS, EDTA, HIDS, and IDS were added to the nutrient solution, respectively. Most of the Fe accumulated in rice tissues was stored in roots after the addition of chelating ligands in the solution. The results indicate that the HIDS would be a potential alternative to environmentally persistent EDTA for the increase of Fe uptake and plant growth. The HIDS also increased As uptake in rice root though its translocation from root to shoot was not augmented. This study reports HIDS for the first time as a promising chelating ligand for the enhancement of Fe bioavailability and As phytoextraction. (C) 2009 Elsevier Ltd. All rights reserved.
  • Seasonal dynamics of biodegradation activities for dimethylarsinic acid (DMA) in Lake Kahokugata, Teruya Maki, Wakana Hirota, Kaori Ueda, Hiroshi Hasegawa, Mohammad Azizur Rahman, CHEMOSPHERE, CHEMOSPHERE, 77(1), 36 - 42, Sep. 2009 , Refereed
    Summary:The microbial activities in aquatic environments significantly influence arsenic cycles such as the turnover between inorganic arsenic and organoarsenic compounds. In Lake Kahokugata, inorganic arsenic was detected at concentrations ranging from 2.8 to 23 nM in all seasons, while the concentrations of dimethylarsinic acid (DMA) produced by microorganisms such as phytoplankton changed seasonally and showed a peak in winter. The changes in the concentrations of methylarsenic species did not correlate with the changes in phytoplankton abundance (chlorophyll a contents), suggesting that DMA-degradation is related to this inconsistency. DMA (1 mu M) added into the lake water was converted to inorganic arsenic at 20 degrees C only under anaerobic and dark conditions, while DMA degradation was diminished under aerobic or light conditions. Moreover, DMA added to the lake water samples collected through four seasons was degraded at the same rates under anaerobic and dark conditions at 20 degrees C. However, at 30 degrees C, 1 mu M of DMA in the summer lake water samples was rapidly degraded in 7 and 21 d. In contrast, DMA degradation was diminished in the winter lake water samples at 4 degrees C of incubation. Presumably, DMA-biodegradation activities are mainly controlled by changes in the water temperature in Lake Kahokugata, where the arsenic concentrations change seasonally. (C) 2009 Elsevier Ltd. All rights reserved.
  • Mixture of Kosa (Asian dust) and bioaerosols detected in the atmosphere over the Kosa particles source regions with balloon-borne measurements: possibility of long-range transport, Y. Iwasaka, G. -Y. Shi, M. Yamada, F. Kobayashi, M. Kakikawa, T. Maki, T. Naganuma, B. Chen, Y. Tobo, C. S. Hong, AIR QUALITY ATMOSPHERE AND HEALTH, AIR QUALITY ATMOSPHERE AND HEALTH, 2(1), 29 - 38, Mar. 2009
    Summary:Long-range transport of atmospheric microbiota with Asian dust (Kosa) particles is of great concern in Northeast Asia in view of the health effect of Kosa particles on human being, disturbance of ecosystems caused through invasion of new microbe, contribution of microorganisms to biogeochemical cycle on global/regional scales, and others. Information on atmospheric microbes over the desert areas has been desired for a long time. Detection of atmospheric microbiota on the desert regions, on the base of balloon-borne measurements, has been made at Dunhuang, China (40 degrees 00' N, 94 degrees 30' E; east end of Taklamakan desert) in the summer of 2007. The measurements showed that microbiota mixed internally with Kosa particles were frequently floating from the ground to about 2-km heights (above sea level), and possible long-range transport of atmospheric microbiota with dust particles taking local circulations is strongly suggested, causing active mixing of atmospheric dust over the Taklamakan desert from the ground to the free troposphere where westerly jet dominates (Iwasaka et al. in J Geophys Res 108:8652, 2003a, J Geophys Res 108:8644, b). The concentration of the mixed particles of Kosa and microbiota having a size larger than about 1 mu m in diameter is estimated to be about 1 particle/cm(3) at those heights on the basis of measurements of particle concentration with an optical particle counter and analysis of particles having fluorescence light due to dye of DAPI (4'6-diamidino-2 phenylindole) with an epifluorescence microscope. The mixing situation of microbiota and Kosa particles is the important factor controlling atmospheric lifetime of floating microbiota, since the mixing state certainly can protect microbiota from stressful environments [dryness, solar ultraviolet (UV) radiation, low temperature] in the atmosphere, and therefore, it is useful to discuss the data of the first description of microbiota in the atmosphere on the Taklamakan desert.
  • Effect of eutrophication on the distribution of arsenic species in eutrophic and mesotrophic lakes, H. Hasegawa, M. Azizur Rahman, T. Matsuda, T. Kitahara, T. Maki, K. Ueda, SCIENCE OF THE TOTAL ENVIRONMENT, SCIENCE OF THE TOTAL ENVIRONMENT, 407(4), 1418 - 1425, Feb. 2009
    Summary:Effects of eutrophication on arsenic speciation were studied in eutrophic Lake Kiba and mesotrophic Lake Biwa, Japan. By combining hydride generation atomic absorption spectrometry with ultraviolet irradiation, inorganic, methyl and ultraviolet-labile fractions of arsenic were determined. In both Lakes, inorganic species (As(V + III)) dominated over other forms of arsenic all the year round. Most of methylarsenic fraction was dimethylarsinic acid (DMAA), and the concentration of monomethylarsonic acid (MMAA) was below the detection limit. Measurements of size-fractioned arsenic concentrations in water column indicate that most of the DMAA was distributed in truly dissolved fraction (< 10 kDa), while ultraviolet-labile fractions were distributed in particulate (> 0.45 mu m) and colloidal (10 kDa-0.45 mu m) fractions. Arsenic speciation in eutrophic Lake Kiba fluctuated greatly with season. The ultraviolet-labile fractions were observed with the increase of DMAA from May to October, and they disappeared with the decrease of DMAA in January. In mesotrophic Lake Biwa, the ultraviolet-labile fractions of arsenic were not influenced as much as those in eutrophic Lake Kiba. On the other hand DMAA concentration was higher in Lake Biwa compared to that in Lake Kiba. The results suggest that the biosynthesis of complex organoarsenicals was enhanced by eutrophication, and the arsenic speciation would be influenced by the balance of biological processes in natural waters. (C) 2008 Elsevier B.V. All rights reserved.
  • Composition of halophilic bacteria survived in bioaerosol, Teruya Maki, Shinzi Susuki, Fumihisa Kobayashi, Makiko Kakikawa, Maromu Yamada, Tomomi Higashi, Chunsang Hong, Yutaka Tobo, Hiroshi Hasegawa, Kazumasa Ueda, Yasunobu Iwasaka, CURRENT RESEARCH TOPICS IN APPLIED MICROBIOLOGY AND MICROBIAL BIOTECHNOLOGY, CURRENT RESEARCH TOPICS IN APPLIED MICROBIOLOGY AND MICROBIAL BIOTECHNOLOGY, 193 - +, 2009 , Refereed
    Summary:The Asian dust phenomena, Kosa, have possibility to carry the microbial particles (Kosa bioaerosol) influencing the microbial habitats and the human health in Japan. In this study the bioacrosol were collected at 600 m and 2 in above ground in Kanazawa city at the Kosa coming season, April in 2007. In the culture media based on seawater and lake water, the bioaerosol at 600 m indicated the microbial growth only in the seawater medium, but no growth in the lake water medium. The bioaerosol at 2 m grew in the both media. The halophilic bacteria would maintain viable activities in the atmosphere. Furthermore, the microorganisms in the bioaerosol at 2 m indicated the better growth in this order of 0%, 3%, and 10% of NaCl concentration, and no growth was detected in the 20% NaCl medium. According to the PCR-DGGE (denaturing gradient gel electrophoresis) analysis, same bacterial species were detected in the every NaCl concentration of culture medium, and other bacterial species could grow only in the culture media with 3% or 10% NaCl concentrations. Therefore, the halophilic or halotolerant bacteria would survive in the aerosol at 2 m above ground, and may be related to the microbial transport across the ground-atmosphere.
  • Seasonal dynamics of bacterial population degrading dimethylarsenic acid in Lake Kahokugata, Wakana Hirota, Teruya Maki, Tastuya Kakimoto, Takashi Shimada, Hiroshi Hasegawa, Kazumasa Ueda, CURRENT RESEARCH TOPICS IN APPLIED MICROBIOLOGY AND MICROBIAL BIOTECHNOLOGY, CURRENT RESEARCH TOPICS IN APPLIED MICROBIOLOGY AND MICROBIAL BIOTECHNOLOGY, 333 - 337, 2009 , Refereed
    Summary:The degradation processes of organoarsenic compounds in aquatic environments would depend on the bioactivities of microorganisms and significantly influence the cycles of the arsenic Species. The concentrations of arsenic species were determined in Lake Kahokugata. During the all season, the inorganic arsenic was detected. while the dimethylarsinic acid (DMAA) appeared in only winter seasons, and MMAA was not detected. Moreover, when DMAA was added to the water samples of Lake Kahokugata collected at every month from June in 2005 to November in 2006, the DMAA in the sample water of all seasons decreased and was converted to inorganic arsenic until the 28th day Of incubation. According to the Most Probable Number (MPN) procedure, the DMAA-degrading bacteria were detected at cell densities ranged from 120 cells/mL to 2 100 cells/mL during the all season. These facts Suggested that the lake water Of all season in Lake Kahokugata possessed the microbial activities for DMAA decomposition. To determine the composition of DMAA-degrading bacteria, the total 352 isolates obtained as dominated bacterial species were analyzed by the restriction-fragment-length polymorphism (RFLP) analysis of 16S rDNA genes. As a result, total 352 isolates were classified into 10 types of which the rates of total isolate numbers indicated seasonal changes. The diverse compositions of DMAA-degrading bacteria would seasonally change and control the organoarsenic degradation contributing 10 the seasonal arsenic cycles in Kahokugata.
  • Influence of phosphate and iron ions in selective uptake of arsenic species by water fern (Salvinia natans L.), M. Azizur Rahman, H. Hasegawa, K. Ueda, T. Maki, M. Mahfuzur Rahman, CHEMICAL ENGINEERING JOURNAL, CHEMICAL ENGINEERING JOURNAL, 145(2), 179 - 184, Dec. 2008
    Summary:In the present Study, the effect of phosphate ion anti iron hydroxides (Fe-plaques) on the selective uptake of arsenic species by water fern (Salvinia natans L.) was investigated. The plants were grown for 5 days it) aqueous Murashige and Skoog (MS) culture media modified in arsenic and phosphate concentrations. Arsenic accumulations in S. natans L. increased with the increase of arsenate and DMAA concentrations in the culture solutions. Compared to the control treatment, S. natans L. accumulated significantly higher amount of arsenic from phosphate-deficient solutions, when the source was arsenate. However, arsenic uptake was not affected significantly by phosphate, when the source was dimethylarsinic acid (DMAA). From solutions containing 100 p M of phosphate and 4.0 mu M of either arsenate or DMAA, the S. natans L. accumulated 0.14 +/- 0.02 and 0.02 +/- 0.00 mu mol (g dry weight)(-1) of arsenic, respectively. In contrast, plants accumulated 0.24 +/- 0.06 and 0.03 +/- 0.00 mu mol (g dry weight)(-1) of arsenic from solutions containing 4.0 mu M of either arsenate and DMAA in phosphate deficient conditions, respectively. Thus, it is reasonable to state that increasing phosphate concentration in culture solutions decreased the arsenic uptake into the water fern significantly, when the source was arsenate. Moreover, arsenic and phosphate content in plant tissue correlated significantly (r=-0.66; p<0.05). when initial source was arsenate while there were no correlation between arsenic and phosphate, where initial source was DMAA (r=-0.077; p>0.05). Similarly, significant correlation was observed between arsenic anti iron content in plant tissues (r=0.66; p<0.05). when initial source was arsenate while the correlation was not significant (r=0.23; p<0.05), when initial source was DMAA. The results indicate the adsorption of arsenate on Fe-plagues of aquatic plant surfaces. Furthermore, the study demonstrates that the DMAA uptake mechanisms into the water fern are deferent from those of arsenate. (C) 2008 Elsevier B.V. All rights reserved.
  • Arsenic uptake by aquatic macrophyte Spirodela polyrhiza L.: Interactions with phosphate and iron, M. Azizur Rahman, H. Hasegawa, K. Ueda, T. Maki, M. Mahfuzur Rahman, JOURNAL OF HAZARDOUS MATERIALS, JOURNAL OF HAZARDOUS MATERIALS, 160(2-3), 356 - 361, Dec. 2008
    Summary:The uptake of arsenate (As(V)) and dimethylarsinic acid (DMAA) by aquatic macrophyte Spirodela polyrhiza L was investigated to determine the influence of arsenic interaction with PO(4)(3-) and Fe ions. Plants were grown hydroponically on standard Murashige and Skoog (MS) culture solutions. Arsenic concentrations in Fe-oxide (Fe-plaque) on plant surfaces were determined by citrate-bicarbonate-ethylenediaminetetraacetic acid (CBE) technique. S. polyrhiza L. accumulated 51-fold arsenic from arsenate solution compared to that from DMAA solution with initial concentrations of 4.0 and 0.02 mu M of arsenic and phosphate, respectively. The arsenate uptake was negatively (p < 0.001) correlated with phosphate uptake and positively (p < 0.05) correlated with iron uptake. About 56% of the total arsenic was accumulated into the plant tissues while 44% was adsorbed on Fe-plaque (CBE-extract), when the plants were grown on arsenate solution. The DMAA uptake into the plant was neither affected by the phosphate concentrations nor correlated (p > 0.05) with iron accumulation. The results suggest that adsorption of arsenate on Fe-plaque of the surface of S. polyrhiza L contributes to the arsenic uptake significantly. Thus, arsenate uptake in S. polyrhiza L. occurred through the phosphate uptake pathway and by physico-chemical adsorption on Fe-plaques of plant surfaces as well. The S. polyrhiza L uses different mechanisms for DMAA uptake. (C) 2008 Elsevier B.V. All rights reserved.
  • Dustborne microorganisms in the atmosphere over an Asian dust source region, Dunhuang, Makiko Kakikawa, Fumihisa Kobayashi, Teruya Maki, Maromu Yamada, Tomomi Higashi, Bin Chen, Guangyu Shi, Chunsang Hong, Yutaka Tobo, Yasunobu Iwasaka, AIR QUALITY ATMOSPHERE AND HEALTH, AIR QUALITY ATMOSPHERE AND HEALTH, 1(4), 195 - 202, Dec. 2008 , Refereed
    Summary:The dust event injects microorganisms into the atmosphere and could facilitate the dispersal of biological particles affecting leeward ecosystem and human health. In this study, the dustborne microorganisms in the atmosphere over the Taklimakan Desert, Asian dust source, were identified by culture-independent method. Dusts were collected using a balloon at about 800 m above the ground in an Asian dust source region, Dunhuang. After DNA were directly extracted from the dusts collected filters, 16S and 18S rRNA genes of microorganisms were amplified, cloned, and sequenced. The rDNA sequence data indicated that dust particles include fungi closely related to Rickenella fibula, Ceriporiopsis gilvescens, and bacteria belonging to the genus Brevibacillus, Staphylococcus, Rhodococcus, Delftia, Pseudomonas, and Agrobacterium tumefaciens. These results suggest that dust particles in the atmosphere over Dunhuang could carry these many fungi and bacteria and might play a significant role in leeward ecosystem.
  • Phylogenetic diversity and vertical distribution of a halobacterial community in the atmosphere of an Asian dust (KOSA) source region, Dunhuang City, Teruya Maki, Shinzi Susuki, Fumihisa Kobayashi, Makiko Kakikawa, Maromu Yamada, Tomomi Higashi, Bin Chen, Guangyu Shi, Chunsang Hong, Yutaka Tobo, Hiroshi Hasegawa, Kazumasa Ueda, Yasunobu Iwasaka, AIR QUALITY ATMOSPHERE AND HEALTH, AIR QUALITY ATMOSPHERE AND HEALTH, 1(2), 81 - 89, Oct. 2008 , Refereed
    Summary:The microbial communities transported by Asian desert dust (KOSA) events have attracted much attention as bioaerosols because the transported microorganisms are thought to influence the downwind ecosystems in Korea and Japan. We have analyzed bioaerosol samples collected at 10 and 800 m above the ground within the KOSA source area, Dunhuang City, China. The samples were studied by epifluorescent microscopy, revealing the presence of bacterial cells attached to mineral particles. The microorganisms in the bioaerosol samples were able to grow in media containing up to 20% NaCl, suggesting that bacteria tolerant to high salinities remain viable in the atmosphere. Phylogenetic analysis using 16S rDNA sequences revealed that halobacterial communities in the bioaerosol samples collected at both 10 and 800 m above the ground comprised a few bacterial species related to Bacillus pumilus and Staphylococcus spp. The active mixing processes of the boundary layer presumably transports viable halotolerant bacteria into the free atmosphere, where the long-range atmospheric transport of desert dust is frequently observed.
  • Influence of chelating ligands on arsenic uptake by hydroponically grown rice seedlings (Oryza sativa L.): A preliminary study, Mohammad Azizur Rahman, Hiroshi Hasegawa, Kazumasa Ueda, Teruya Maki, M. Mahfuzur Rahman, CLEAN-SOIL AIR WATER, CLEAN-SOIL AIR WATER, 36(5-6), 521 - 527, Jun. 2008 , Refereed
    Summary:Ferric (oxyhydro-)oxides (FeOx) precipitate in the rhizosphere at neutral or alkaline pH and are adsorbed on the plant root surfaces. Consequently, the higher binding affinity of arsenate to FeOx and the low iron phytoavailability of the precipitated FeOx make the phytoremediation of arsenic difficult. In the present study, the influence of chelating ligands on arsenic and iron uptake by hydroponically grown rice seedlings (Oryza sativa L.) was investigated. When chelating ligands were not treated to the growth medium, about 63 and 71% of the total arsenic and iron were distributed in the root extract (outer root surfaces) of rice, respectively. On the other hand, ethylenediaminetetraacetic acid (EDTA), ethylenediaminedisuccinic acid (EDDS) and hydroxyiminodisuccinic acid (HIDS) desorbed a significant amount of arsenic from FeOx of the outer root surfaces. Therefore, the uptake of arsenic and iron into the roots and their subsequent translocation to the shoots of the rice seedlings increased significantly. The order of increasing arsenic uptake by chelating ligands was HIDS > EDTA > EDDS. Methylglycinediacetic acid (MGDA) and iminodisuccinic acid (IDS) might not be effective in arsenic solubilization from FeOx. The results suggest that EDDS and HIDS would be a good and environmentally safe choice to accelerate arsenic phytoavailability in the phytoremediation process because of their biodegradability and would be a competent alternative to the widely used non-biodegradable and environmentally persistent EDTA.
  • Adsorption of gold(III), platinum(W) and palladium(II) onto glycine modified crosslinked chitosan resin, A. Ramesh, H. Hasegawa, W. Sugimoto, T. Maki, K. Ueda, BIORESOURCE TECHNOLOGY, BIORESOURCE TECHNOLOGY, 99(9), 3801 - 3809, Jun. 2008
    Summary:The adsorption of Au(III), Pt(IV) and Pd(II) onto glycine modified crosslinked chitosan resin (GMCCR) has been investigated. The parameters studied include the effects of pH, contact time, ionic strength and the initial metal ion concentrations by batch method. The optimal pH for the adsorption of Au(III), Pt(IV) and Pd(II) was found to range from 1.0 to 4.0 and the maximum uptake was obtained at pH 2.0 for Au(III), Pt(IV) and Pd(II). The results obtained from equilibrium adsorption studies are fitted in various adsorption models such as Langmuir and Freundlich and the model parameters have been evaluated. The maximum adsorption capacity of GMCCR for Au(III), Pt(IV) and Pd(II) was found to be 169.98, 122.47 and 120.39 mg/g, respectively. The kinetic data was tested using pseudo-first-order and pseudo-second-order kinetic models and an intraparticle diffusion model. The correlation results suggested that the pseudo-second-order model was the best choice among all the kinetic models to describe the adsorption behavior of Au(III), Pt(IV) and Pd(II) onto GMCCR. Various concentrations of HCl, thiourea and thiourea-HCl solutions were used to desorb the adsorbed precious metal ions from GMCCR. It was found that 0.7 M thiourea-2 M HCl solution provided effectiveness of the desorption of Au(III), Pt(IV) and Pd(II) from GMCCR. The modification of glycine on crosslinked chitosan resin (CCR) was studied by Fourier transform infrared spectrometry (FTIR) and scanning electron microscopy (SEM). (c) 2007 Elsevier Ltd. All rights reserved.
  • Influence of EDTA and chemical species on arsenic accumulation in Spirodela polyrhiza L. (duckweed), M. Azizur Rahman, H. Hasegawa, K. Ueda, T. Maki, M. M. Rahman, ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY, ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY, 70(2), 311 - 318, Jun. 2008
    Summary:The influence of ethylenediaminetetraacetic acid (EDTA) and chemical species on arsenic accumulation in aquatic floating macrophyte Spirodela polyrhiza L. (duckweed) was investigated. The uptake of inorganic arsenic species (arsenate; As(V) and arsenite; As(111)) into the plant tissue and their adsorption on iron plaque of plant surfaces were significantly (p < 0.05) higher than those of organic species (monomethylarsonic acid (MMAA) and dimethylarsinic acid (DMAA)). The addition of EDTA to the culture media increased the uptake of As(V) and As(III) into the plant tissue though the MMAA and DMAA uptake were not affected. About 4-6% of the inorganic arsenic species were desorbed or mobilized from iron plaque by EDTA. Desorption of organic arsenic species was not affected by EDTA addition because the co-precipitation occurs only with inorganic species. Phosphate uptake was not affected by EDTA though its concentration in citrate-bicarbonate-EDTA (CBE)-extract was much higher than that of plant tissue. Iron uptake into the plant increased significantly (p > 0.05) by EDTA addition to the culture media while its concentration in CBE-extract decreased significantly (p < 0.05). The As (inorganic)/ Fe ratios in plant were higher than those of CBE-extract which indicate the increased uptake of these arsenic species into the plant relative to the iron. The lower As(organic)/Fe ratios in plant and on CBE-extract suggest the reduction of accumulation of these arsenic species relative to the iron. (c) 2007 Elsevier Inc. All rights reserved.
  • Arsenic accumulation in duckweed (Spirodela polyrhiza L.): A good option for phytoremediation, M. Azizur Rahman, Hiroshi Hasegawa, Kazumasa Ueda, Teruya Maki, Chikako Okumura, M. Mahfuzur Rahman, CHEMOSPHERE, CHEMOSPHERE, 69(3), 493 - 499, Sep. 2007 , Refereed
    Summary:Some unavoidable drawbacks of traditional technologies have made phytoremediation a promising alternative for removal of arsenic from contaminated soil and water. In the present study, the potential of an aquatic macrophyte Spirodela polyrhiza L. for phytofiltration of arsenic, and the mechanism of the arsenic uptake were investigated. The S. polyrhiza L. were grown in three test concentrations of arsenate and dimethylarsinic acid (DMAA) (i.e. 1.0, 2.0 and 4.0 mu M) with 0 (control), 100 or 500 mu M of phosphate. One control treatment was also set for each test concentrations of arsenic. The PO43- concentration in control treatment was 0.02 mu M. When S. polyrhiza L. was cultivated hydroponically for 6 d in culture solution containing 0.02 mu M phosphate and 4.0 mu M arsenate or DMAA, the arsenic uptake was 0.353 +/- 0.003 mu mol g(-1) and 7.65 +/- 0.27 nmol g(-1), respectively. Arsenic uptake into S. polyrhiza L. was negatively (p < 0.05) correlated with phosphate uptake when arsenate was applied to the culture solutions owing to similar in the sorption mechanism between AsO43- and PO43-, and positively (p < 0.05) correlated with iron uptake due to adsorption of AsO43- onto iron oxides. Thus, the S. polyrhiza L. accumulates arsenic by physico-chemical adsorption and via the phosphate uptake pathway when arsenate was added to the solutions. These results indicate that S. polyrhiza L. would be a good arsenic phytofiltrator. In contrast, DMAA accumulation into S. polyrhiza L. was neither affected by the phosphate concentration in the culture nor correlated (p > 0.05) with iron accumulation in plant tissues, which indicates that S. polyrhiza L. uses different mechanisms for DMAA uptake. (C) 2007 Elsevier Ltd. All rights reserved.
  • Adsorption of inorganic and organic arsenic from aqueous solutions by polymeric Al/Fe modified montmorillonite, A. Ramesh, H. Hasegawa, T. Maki, K. Ueda, SEPARATION AND PURIFICATION TECHNOLOGY, SEPARATION AND PURIFICATION TECHNOLOGY, 56(1), 90 - 100, Aug. 2007
    Summary:Adsorption of arsenite [As(III)], arsenate [As(V)] and dimethylarsinate (DMA) from aqueous solutions onto polymeric Al/Fe modified montmorillonite was studied. Batch adsorption studies were carried out on the adsorption of As(III), As(V) and DMA as a function of contact time, pH, adsorbent dose and initial metal concentration. Fourier transform infrared spectrometry (FT-IR) and scanning electron microscopy (SEM) were used to analyze the functional groups and surface morphology of the montmorillonite or polymeric Al/Fe modified montmorillonite, respectively. SEM images show that modification with polymeric Al/Fe species reduces the clay particle size and aggregation. The results indicate that the maximum adsorption of polymeric Al/Fe modified montmorillonite was obtained in the pH range 3.0-6.0 for As(V), 7.0-9.0 for As(III) and 3.0-7.0 for DMA. The adsorption data was analyzed by both Freundlich and Langmuir isotherm models and the data was well fit by the Freundlich isotherm model. Kinetic data correlated well with the pseudo-second-order kinetic model, suggesting that the adsorption process might be chemical sorption. Thermodynamic studies showed that the adsorption process was endothermic and spontaneous in nature. The presence of phosphate and iron reduced the adsorption efficiency of arsenic, whereas other common coexisting ions had no significant effect on arsenic adsorption. The desorption studies were carried out using dilute NaCl solution. (c) 2007 Elsevier B.V. All rights reserved.
  • Adsorption of platinum(IV), palladium(II) and gold(III) from aqueous solutions onto L-lysine modified crosslinked chitosan resin, Kensuke Fujiwara, Attinti Ramesh, Teruya Maki, Hiroshi Hasegawa, Kazumasa Ueda, JOURNAL OF HAZARDOUS MATERIALS, JOURNAL OF HAZARDOUS MATERIALS, 146(1-2), 39 - 50, Jul. 2007 , Refereed
    Summary:Crosslinked chitosan resin chemically modified with L-lysine has been used to investigate the adsorption of Pt(IV), Pd(II) and Au(III) from aqueous solutions. Batch adsorption studies were carried out with various parameters, such as initial metal ion concentration, contact time, pH and temperature. The maximum adsorption capacity was found at pH 1.0 for Pt(IV), at pH 2.0 for Au(III) and Pd(II). Langmuir and Freundlich isotherm models were applied to analyze the experimental data. The best interpretation for the experimental data was given by the Langmuir isotherm and the maximum adsorption capacity was found to be 129.26 mg/g for Pt(IV), 109.47 mg/g for Pd(II) and 70.34 mg/g for Au(III). The kinetic data was tested using pseudo-first-order and pseudo-second-order kinetic models. Kinetic data correlated well with the pseudo-second-order kinetic model, indicating that the chemical sorption was the rate-limiting step. Thermodynamic parameters like Gibbs free energy (Delta G degrees), enthalpy (Delta H degrees) and entropy (Delta S degrees) were evaluated by applying the Van't Hoff equation. The thermodynamic study indicated that the adsorption process is spontaneous and exothermic in nature. The desorption studies were carried out using various reagents. The maximum percent desorption of precious metal ions were obtained when the reagent 0.7 M thiourea-2 M HCl was used. (C) 2006 Elsevier B.V. All rights reserved.
  • Nanometer-sized alumina coated with chromotropic acid as solid phase metal extractant from environmental samples and determination by inductively coupled plasma atomic emission spectrometry, Attinti Ramesh, Bobba Aparna Devi, Hiroshi Hasegawa, Teruya Maki, Kazumasa Ueda, MICROCHEMICAL JOURNAL, MICROCHEMICAL JOURNAL, 86(1), 124 - 130, Jun. 2007 , Refereed
    Summary:A method for solid phase extraction of trace metals such as Cd(2+), Cr(6+), Cu(2+), Fe(3+), Mn(2+), Ni(2+), Pb(2+) and Zn(2+) using nanometer coated with chromotropic acid prior to determination by inductively coupled plasma atomic emission spectrometry (ICP-AES) has been developed. Various influencing parameters on the separation and preconcentration of trace metals, pH, flow rate, sample volume, amount of adsorbent, concentration of eluent and sorption kinetics have been studied. The detection limits for Cd(2+), Cr(6+), Cu(2+), Fe(3+), Mn(2+), Ni(2+), Pb(2+) and Zn(2+) were found to be 0.14, 0.62, 0.22, 0.54, 0.27, 0.28, 0.53 and 0.38 ng ml-(1), respectively. The adsorption capacity of the solid phase adsorption material is 10.3, 11.3, 14.5, 16.4, 15.1, 11.7, 15.4 and 16.8 mg g(-1) for Cd(2+), Cr(6+), Cu(2+), Fe(3+), Mn(2+), Ni(2+), Pb(2+) and Zn(2+), respectively. The preconcentration factor was obtained in the range of 50-100 for all studied metal ions. Coexisting ions over a high concentration range have not shown any significant effects on the determination of aforesaid metal ions. The accuracy of the proposed method was tested by standard reference materials (NIST 1643e: water, NIST 1573a: tomato leaves and NIST 1568a rice flour) and natural waters and the results obtained were in good agreement with the certified values. (C) 2007 Elsevier B.V. All rights reserved.
  • Isolation of monomethylarsonic acid-mineralizing bacteria from arsenic contaminated soils of Ohkunoshima Island, Teruya Maki, Noriko Takeda, Hiroshi Hasegawa, Kazumasa Ueda, APPLIED ORGANOMETALLIC CHEMISTRY, APPLIED ORGANOMETALLIC CHEMISTRY, 20(9), 538 - 544, Sep. 2006 , Refereed
    Summary:Chemical warfare agents, composed of harmful organoarsenic compounds have contaminated the soils of Ohkunoshima Island with high levels of arsenic. As a basic research establishing useful bioremediation techniques, environmental factors such as arsenic concentrations and bacterial biomass in the soils were investigated. Among the five stations of Ohkunoshima Island, the soils of four stations were contaminated by high levels of arsenic compounds at concentrations of 125, 12.7, 3.29 and 0.504 g/kg soil, while the other station with low arsenic concentrations of 0.007 g/kg soil was considered an uncontaminated area. The distribution of arsenic compounds originating from the chemical weapon agent differs among the various areas of Ohkunoshima Island. The cell densities of arsenate-resistant bacteria also varied among the five stations, ranging from 10(6) to 10(8) cells/g soil. In an attempt to isolate bacteria that strongly mineralize the organoarsenic compounds, the mineralization activities for monomethylarsonic acid [MMAA(V)] of 48 isolates of arsenate-resistant bacteria were determined. Only nine isolates reduced 140 mu g/l of MMAA(V), giving decreasing percentages ranging from 5 to 100% within 14 days. Among the nine isolates, two remarkably converted 140 mu g/l of MMAA to more than 71 mu g/l of inorganic arsenic. Presumably only specific members of the environmental bacterial population have strong mineralization activities for MMAA. Phylogenetic analysis using 16S rDNA sequences showed that the two isolates belonged to the Pseudomonas putida strains, which are known to have strong mineralization activity for various organic compounds. In the soil contaminated by arsenic at a high level, few bacteria in the arsenate-resistant bacterial group would significantly mineralize orgartoarsenic compounds. Copyright (c) 2006 John Wiley & Sons, Ltd.
  • Bacterial degradation of antibiotic residues in marine fish farm sediments of Uranouchi Bay and phylogenetic analysis of antibiotic-degrading bacteria using 16S rDNA sequences, Teruya Maki, Hiroshi Hasegawa, Hiroyuki Kitami, Kyoko Fumoto, Yukihiro Munekage, Kazumasa Ueda, FISHERIES SCIENCE, FISHERIES SCIENCE, 72(4), 811 - 820, Aug. 2006 , Refereed
    Summary:Antibiotic residues in marine sediments of fish farms negatively influence microbial ecologic systems. The microbial degradation of antibiotic residues was experimentally examined in the marine sediments of Uranouchi Bay, to which one of five antibiotics was added. After incubation reducing physical factors, ampicillin, doxycycline, oxytetracycline, and thiamphenicol were significantly degraded, while josamycin maintained most of the initial amounts. The isolates resistant to ampicillin, josamycin, oxytetracycline, or thiamphenicol degraded each antibiotic in wide ranges of degrees, whereas the isolates degrading doxycycline were not obtained. Microbial degradation may contribute to the disappearance of ampicillin, doxycycline, oxytetracycline, and thiamphenicol in the fish farm. In contrast, the disappearance of josamycin would depend on physical factors, but the bacteria degrading josamycin at least exist in the marine sediments. Phylogenetic analysis using 16S rDNA sequences demonstrated that the antibiotic-resistant isolates formed several clusters in the Gram-positive bacterial group, the Flavobacterium-Cytophaga-Bacteroides group, and the proteobacteria subdivisions. The antibiotic-resistant bacterial population would be composed of various species including ubiquitous coastal bacterial groups. Several species of antibiotic resistant bacteria show antibiotic degradation activities, and appear to contribute to the disappearance of antibiotics in Uranouchi Bay.
  • Seasonal dynamics of dimethylarsenic acid degrading bacteria dominated in Lake Kibagata, Teruya Maki, Hiroshi Watarai, Tatsuya Kakimoto, Makoto Takahashi, Hiroshi Hasegawa, Kazumasa Ueda, GEOMICROBIOLOGY JOURNAL, GEOMICROBIOLOGY JOURNAL, 23(5), 311 - 318, Jul. 2006 , Refereed
    Summary:Degradation processes of organoarsenic compounds significantly influence arsenic cycles in aquatic environments and would depend on the bacterial activities. The bacterial population involving dimethylarsinic acid (DMAA) degradation was investigated in Lake Kibagata from April to December in 2003. During the experimental period, the methylated arsenic was not detected, although the inorganic arsenic concentration ranged from 3.4 nM to 9.2 nM. Moreover, in the sample water of Lake Kibagata to which DMAA added, DMAA decreased while inorganic arsenic increased for 25 days. These facts suggested that the bacteria remineralized methylate arsenic species to inorganic arsenic. In fact, monitoring the use of Most Probable Number (MPN) procedure demonstrated that the DMAA-degrading bacteria exist at cell densities ranged from 41 cells/ml to 510 cells/ml. To determine the composition of DMAA-degrading bacteria, the total 110 isolates obtained as dominated bacterial species were analyzed by the restriction-fragment-length polymorphism (RFLP) analysis of 16S rDNA. As a result, total 110 isolates were classified into 12 types, of which 4 types dominated during the spring and/or fall seasons, and the rest 8 types dominated during summer season. DMAA degrading activities of the 110 isolates ranged at various degrees. Especially, the some isolates of fall season tend to show high degradation activities. The phylogenetic analysis using 16S rDNA revealed that the representative isolates formed several clusters in the gram-positive bacterial group and the proteobacteria subdivision. The diverse compositions of DMAA-degrading bacteria would seasonally change to control the rates of organoarsenic degradation in Kibagata.
  • Determination of Cu, Pb, Fe, and Zn in plant component polymers of a hyperaccumulating plant, Fumihisa Kobayashi, Teruya Maki, Yoshitoshi Nakamura, Kazumasa Ueda, Analytical Sciences, Analytical Sciences, 21(12), 1553 - 1556, Dec. 2005
    Summary:Phytoremediation is an innovative technology that utilizes the natural properties of plants to remediate hazardous waste sites. For more cost-effective phytoremediation, it is important to utilize a hyperaccumulating plant after phytoremediation, i.e. the recovery of valuable metals and the production of useful materials. In this work, the determination of metals in plant component polymers in a fern, Athyrium yokoscense, as a hyper-accumulating plant was established using steam explosion, Wayman's extraction method, and ICP emission spectrometry. After A. yokoscense plants were treated by steam explosion, the steam-exploded A. yokoscense were separated into four plant component polymers, i.e. water-soluble material fraction, holocellulose fraction, methanol-soluble lignin fraction, and residual lignin fraction. The concentrations of Cu, Pb, Fe, and Zn in these plant component polymers and the dry weights of plant component polymers were measured. These analytical process determining metals in the plants will contribute to not only the evaluation and the efforts of phytoremediation using a hyperaccumulating plant, but also to the development of more effective phytoremediation. 2005 © The Japan Society for Analytical Chemistry.
  • Phylogenetic analysis of intracellular bacteria of a harmful marine microalga, Heterocapsa circularisquama (Dinophyceae), T Maki, Yoshinaga, I, N Katanozaka, Imai, I, AQUATIC MICROBIAL ECOLOGY, AQUATIC MICROBIAL ECOLOGY, 36(2), 123 - 135, Jul. 2004
    Summary:Heterocapsa circularisquama, a noxious marine dinoflagellate, has frequently caused red tides and killed cultured bivalves in western Japanese embayments. Observations by electron and epifluorescence microscopy revealed that many bacterial particles were detected inside the H. circularisquama cells. To elucidate the identity and origin of the intracellular bacteria associated with H, circularisquama, bacterial 16S ribosomal RNA genes (16S rDNA) were directly amplified by polymerase chain reaction from 5 clonal cultures of the algal strains that had been isolated from different localities. After cloning, randomly selected clones including the bacterial 16S rDNA fragments were sequenced. The results showed that intracellular bacterial populations consisted of only 2 ribotypes of bacteria, even though the algal strains were established from different localities. One ribotype (bac-G), which was dominant in the intracellular bacterial population, belonged to the gamma-proteobacteria group, and the other (bac-F) clustered with the Flexibacter-Cytophaga-Bacteroides group, Both of these are novel species of endosymbiotic bacteria because of their unique 16S rDNA sequences. Furthermore, the populations of extracellularly associated bacteria were also composed of bac-G and bac-F, indicating that they originated from the intracellular bacteria. Fluorescence in situ hybridization targeting 16S rRNA indicated that bac-G appeared to localize on the algal nuclear surface, while bac-F was distributed in the cytoplasmic space of algal cells. These results strongly suggest that only a few species of specific bacteria reside and share their habitat in the H. circularisquama cells as endosymbionts.
  • Detection of Iron(III)-Binding Ligands Originating from Marine Phytoplankton Using Cathodic Stripping Voltammetry, Hiroshi Hasegawa, Teruya Maki, Kohnosuke Asano, Kentaro Ueda, Kazumasa Ueda, Analytical Sciences, Analytical Sciences, 20(1), 89 - 93, Jan. 2004
    Summary:The sample preparation and analytical methodology are described for detecting biologically produced iron(III)-binding ligands in laboratory cultures of coastal marine phytoplankton. The iron (III)-binding ligands from the culture media were purified by passage through a column packing with a hydrophobic absorbent. The concentrations and stability constants of the ligands were determined by adsorptive cathodic stripping voltammetry with competitive ligand equilibration. The analytical results of the cultivated cultures suggest that eukaryotic phytoplankton would produce iron(III)-binding ligands in analogy with other microorganisms.
  • Classification for dimethylarsenate-decomposing bacteria using a restrict fragment length polymorphism analysis of 16S rRNA genes, T Maki, H Hasegawa, H Watarai, K Ueda, ANALYTICAL SCIENCES, ANALYTICAL SCIENCES, 20(1), 61 - 68, Jan. 2004
    Summary:A new monitoring system for bacterial communities involving dimethylarsinic acid (DMAA) decomposition was provided by combining the MPN (Most Probable Number) method and RFLP (restriction-fragment-length polymorphism analysis). The abundance of DMAA decomposing bacteria was estimated by the MPN method using a bacterial culture medium, which included DMAA as the sole carbon source, indicating bacterial cell densities of 1700 cells/ml in Lake Kahokugata and 330 cells/ml in Lake Kibagata. After isolating the dominant bacteria using agar plates, the isolates were classified into some genotype groups by RFLP analysis using 16S rDNA sequences. Classification of the RFLP analysis indicated that 14 isolates of Lake Kahokugata were classified into 6 types, which included 2 dominant types related to genus Pseudomonas, while 8 isolates of Lake Kibagata displayed 6 types including one or two isolates. Moreover, the RFLP types were unique for each lake, suggesting that DMAA decomposing bacteria were specific for the aquatic environment related to the arsenic cycle. The activities of DMAA decomposition mostly matched with the RFLP type category of the isolates. Accordingly, combining the MPN method with the RFLP analysis will play an important role in elucidating the distributions and dynamics of the DMAA-decomposing bacterial community.
  • Relationships between intracellular bacteria and the bivalve killer dinoflagellate Heterocapsa circularisquama (Dinophyceae), T Maki, Imai, I, FISHERIES SCIENCE, FISHERIES SCIENCE, 67(5), 794 - 803, Oct. 2001
    Summary:Relationships between the growths of five different clonal strains of Heterocapsa circularisquama and intracellular bacteria were investigated using culture experiments. Although each H. circularisquama strain culture was established from one cell by repeated and careful washings with micropipettes, intracellular and extracellular bacteria in each strain culture were still observed under a epifluorescence microscope using the DAPI (4 ' ,6-diamidino-2-phenylindole) staining technique. The extracellular bacteria are derived, presumably, from the inside of algal cells after the death and collapse of algal cells in culture. Using an electron microscope, bacteria were constantly observed in the cytoplasm and food vacuoles of H. circularisquama cells. The growth of five algal strains containing bacteria was compared with that of a bacteria-free strain using culture experiments under combined conditions of five different light intensities and five different strengths of culture medium. Bacteria showed no significant effect on the growth or survival of the algal cells. During the algal exponential growth phase, the intracellular bacterial cell numbers per algal cell decreased, whereas the total bacterial cell density in each algal culture increased. Final cell yield (total number) of the intracellular and extracellular bacteria varied considerably according to the algal strains. These results suggest that the intracellular bacteria of H. circularisquama grow or survive depending on the host alga, and that the alga can grow independently.
  • Effects of Harmful Dinoflagellate Heterocapsa circularisquama Cells on the Growth of Intracellular Bacteria, Teruya Maki, Ichiro Imai, Microbes and Environments, Microbes and Environments, 16(4), 234 - 239, 2001
    Summary:The red tide dinoflagellate Heterocapsa circularisquama Horiguchi has intracellular bacteria. The isolation and cultivation of these bacteria were attempted for three-clonal strains of H. circularisquama (HY9423, HA92-1, and HU9433) using various culture media containing cell components of the host alga prepared by homogenization and heat killing, in addition to different organic materials (peptone and extracts). Only one intracellular bacterium of the bacterial population UBb in H. circularisquama strain HU9433 was successfully cultivated on many kinds of culture media. The intracellular bacterial populations of Yb and Ab in the algal clones HY9423 and HA92-1, respectively, could not grow in the culture media used. The presence of live algal cells is thought to be essential for the growth and survival of the bacterial populations Yb and Ab. These results indicate that the degree of dependence of the intracellular bacteria on the host algal cells differs greatly among the algae-bacteria sets of strains. © 2001, Japanese Society of Microbial Ecology & The Japanese Society of Soil Microbiology. All rights reserved.

Works

  • Sampling of KOSA particles

Misc

  • 超分子固相抽出材を用いた環境水中のセレンの価数別分離濃縮法, 宮口真帆, 澤井光, 古庄義明, 牧輝弥, 長谷川浩, 分析化学討論会講演要旨集, 77th, 210,   2017 05 13 , http://jglobal.jst.go.jp/public/201702211182370950
  • As汚染土壌に対するキレート洗浄と抽出メカニズムの解明, 齋藤誠, 澤井光, 山崎将義, 石渡寛之, RAHMAN Ismail M. M, 牧輝弥, 長谷川浩, 分析化学討論会講演要旨集, 77th, 212,   2017 05 13 , http://jglobal.jst.go.jp/public/201702219074181852
  • 電位差滴定法による腐植様物質と金属イオンの安定度定数の決定, 澤井光, 齋藤誠, BEGUM Zinnat Ara, RAHMAN Ismail, Md. Mofizur, 牧輝弥, 一條利治, 長谷川浩, 分析化学討論会講演要旨集, 77th, 93,   2017 05 13 , http://jglobal.jst.go.jp/public/201702246062625973
  • キレート剤水溶液中における有害金属イオンの鉱物表面への吸脱着挙動, 澤井光, 齋藤誠, 牧輝弥, 山崎将義, 石渡寛之, 長谷川浩, 分析化学討論会講演要旨集, 77th, 152,   2017 05 13 , http://jglobal.jst.go.jp/public/201702272525166028
  • 原子間力顕微鏡を用いた個別黄砂粒子の物性評価, 松木篤, 水島悠希, 岩田歩, 渡邊誠, 牧輝弥, 柿川真紀子, 小林史尚, エアロゾル科学・技術研究討論会(CD-ROM), 33rd, ROMBUNNO.F06,   2016 08 31 , https://jglobal.jst.go.jp/detail?JGLOBAL_ID=201602214305873413
  • 汚染土壌中有害金属に対する生分解性キレート剤による湿式分離法の実試料への適用, 地井直行, 澤井光, 牧輝弥, 山崎将義, 石渡寛之, 長谷川浩, 日本分析化学会年会講演要旨集, 65th, 240,   2016 08 31 , http://jglobal.jst.go.jp/public/201602286253069994
  • 土壌中ヒ素のキレート抽出と後処理法の検討, 地井直行, 澤井光, 橋本有未, 牧輝弥, 石渡寛之, 長谷川浩, 分析化学討論会講演要旨集, 76th, 180,   2016 05 14 , http://jglobal.jst.go.jp/public/201602212515892140
  • キレート洗浄を用いた土壌スラッジ中鉛含有量の低減化, 長谷川浩, 澤井光, 地井直行, 牧輝弥, RAHMAN Ismail, Md. Mofizur, 釜本英一, 分析化学討論会講演要旨集, 76th, 151,   2016 05 14 , http://jglobal.jst.go.jp/public/201602232547945387
  • 超分子型固相抽出剤を用いたメッキ廃液中貴金属の抽出分離, 若林友弥, 澤井光, 地井直行, 古庄義明, 牧輝弥, 長谷川浩, 日本分析化学会年会講演要旨集, 64th, 315,   2015 08 26 , http://jglobal.jst.go.jp/public/201502208365019193
  • 湿式キレート洗浄と電解還元を組み合わせた固体廃棄物中の有価金属の回収, 澤井光, 藤田真悠子, 地井直行, 若林友弥, 牧輝弥, 水谷聡, 長谷川浩, 日本分析化学会年会講演要旨集, 64th, 124,   2015 08 26 , http://jglobal.jst.go.jp/public/201502214347645117
  • 生分解性キレート剤を用いた放射性セシウム含有土壌の湿式洗浄の検討, 澤井光, RAHMAN Ismail, Md. Mofizur, 地井直行, 若林友弥, 牧輝弥, 長谷川浩, 日本分析化学会年会講演要旨集, 64th, 316,   2015 08 , http://jglobal.jst.go.jp/public/201502219424973337
  • キレート洗浄を利用した鋳物廃砂中重金属の分離に対するメカノケミカル効果, 澤井光, 藤田真悠子, 地井直行, 若林友弥, 牧輝弥, 水谷聡, 長谷川浩, 分析化学討論会講演要旨集, 75th, 34,   2015 05 09 , http://jglobal.jst.go.jp/public/201502202245813505
  • 汚染土壌中におけるPb及びAsのキレート抽出と逐次抽出法による化学形態解析, 地井直行, 池邊祐哉, 塚越義則, 若林友弥, 澤井光, 牧輝弥, 石渡寛之, 長谷川浩, 分析化学討論会講演要旨集, 75th, 153,   2015 05 09 , http://jglobal.jst.go.jp/public/201502210711978245
  • LC‐MSを用いた生分解性キレート剤の金属イオンの分離分析, 竹村匡史, 澤井光, 工藤寿馬, RAHMAN Ismail, Md. Mofizur, RAHMAN Ismail, Md. Mofizur, 牧輝弥, 長谷川浩, 分析化学討論会講演要旨集, 75th, 157,   2015 05 09 , http://jglobal.jst.go.jp/public/201502215680930577
  • 化学的湿式抽出法に基づいた非鉄製錬ダスト中金属元素の相互分離, 澤井光, 若林友弥, 塚越義則, 牧輝弥, 水谷聡, 長谷川浩, 日本分析化学会年会講演要旨集, 63rd, 45,   2014 09 03 , http://jglobal.jst.go.jp/public/201402254668966776
  • 土壌中セシウムの化学形態解析とキレート剤による湿式洗浄の適用, 澤井光, 盧超, 塚越義則, 若林友弥, 牧輝弥, 長谷川浩, 日本分析化学会年会講演要旨集, 63rd, 262,   2014 09 03 , http://jglobal.jst.go.jp/public/201402288625719670
  • キレート洗浄による汚染土壌中鉛の抽出分離, 塚越義則, 澤井光, 牧輝弥, 水谷聡, 長谷川浩, 日本分析化学会年会講演要旨集, 63rd, 51,   2014 09 03 , http://jglobal.jst.go.jp/public/201402288839224309
  • 有害金属汚染土壌に対するキレート洗浄効果と化学形態の関係, 塚越義則, 澤井光, 池邊祐哉, 地井直行, 牧輝弥, 長谷川浩, 日本分析化学会年会講演要旨集, 63rd, 264,   2014 09 03 , http://jglobal.jst.go.jp/public/201402294417765501
  • アミノポリカルボン酸を洗浄剤に用いた鋳物廃砂の重金属除去と再資源化, 澤井光, 若林友弥, 塚越義則, 叶艶, 牧輝弥, 水谷聡, 長谷川浩, 分析化学討論会講演要旨集, 74th, 63,   2014 05 10 , http://jglobal.jst.go.jp/public/201402216948784097
  • 超分子型固相抽出剤を用いたセシウムの抽出分離, 叶艶, 澤井光, 塚越義則, 若林友弥, 牧輝弥, 長谷川浩, 分析化学討論会講演要旨集, 74th, 144,   2014 05 10 , http://jglobal.jst.go.jp/public/201402227364998860
  • Decontamination of Heavy-Metal-Laden Waste Foundry Sand using Chelant-Assisted Washing Treatment, Sawai Hikaru, Fujita Mayuko, Wakabayashi Tomoya, Tsukagoshi Yoshinori, Maki Teruya, Mizutani Satoshi, Hasegawa Hiroshi, Proceedings of the Annual Conference of Japan Society of Material Cycles and Waste Management, 25, 0,   2014 , http://ci.nii.ac.jp/naid/130005477901
    Summary:Molding sands are used in the foundry industry to produce metal casting-molds during the casting process. A waste foundry sand (WFS) from foundry industry have been reused as construction materials. &nbsp;Heavy metals in the WFS have been demanded to remove from the view point of resource strategy with environmental-friendship. In this study, a decontamination technique of heavy-metal-laden WFS by using chelant-assisted washing was used to the WFS containing copper (1.8 %) and lead (0.43 %).&nbsp; Increasing of EDTA concentration significantly promoted metal dissolution due to conform chelate-complex.&nbsp; A dissolution rate of copper was incremented by adding NH<sub>3</sub> and NaOH as dose-substance.&nbsp; The optimum washing solution was composed of 50 mmol L<sup>-1</sup> EDTA, 0.2 mol L<sup>-1</sup> NaOH and 0.3 mol L<sup>-1</sup> NH<sub>3</sub>. &nbsp;The copper and lead in the WFS were quantitatively removed after 3 times of sequential treatments using comparatively moderate reagents; the removal efficiencies were 113 % and 96 %, respectively.
  • バイオエアロゾルのCCN・IN能, 山下克也, 田尻拓也, 斎藤篤思, 村上正隆, 牧輝弥, 松木篤, 原和崇, 岩田歩, 日本気象学会大会講演予稿集, 104, 383,   2013 10 31 , https://jglobal.jst.go.jp/detail?JGLOBAL_ID=201302256493449531
  • 室内実験から見積もった枯草菌(バイオエアロゾル)の雲凝結核能と氷晶核能, 山下克也, 田尻拓也, 斎藤篤思, 村上正隆, 牧輝弥, 松木篤, 原和崇, 岩田歩, エアロゾル科学・技術研究討論会, 30th, 267, 268,   2013 08 27 , https://jglobal.jst.go.jp/detail?JGLOBAL_ID=201302282256415208
  • キレート‐金属錯体形成を利用した精錬ダスト中金属の選択的抽出, 澤井光, 塚越義則, 盧超, 牧輝弥, 水谷聡, 長谷川浩, 日本分析化学会年会講演要旨集, 62nd, 91,   2013 08 27 , http://jglobal.jst.go.jp/public/201402275165599811
  • 上空のスギ花粉と気候への影響, 岩田歩, 松木篤, 原和崇, 岩本洋子, 柿川真紀子, 牧輝弥, 日本花粉学会大会講演要旨集, 54th, 48,   2013 08 25 , https://jglobal.jst.go.jp/detail?JGLOBAL_ID=201302233548573210
  • 水溶性キレート剤による非鉄精錬ダスト中インジウムの湿式抽出法の開発, 澤井光, 中野俊宏, 蘆超, 牧輝弥, 水谷聡, 長谷川浩, 日本分析化学会年会講演要旨集, 61st, 24,   2012 09 05 , http://jglobal.jst.go.jp/public/201202264239431962
  • キレート洗浄法による非鉄精錬ダスト中インジウムの抽出分離, 澤井光, 牧輝弥, 長谷川浩, 水谷聡, 環境技術学会年次大会予稿集, 12th, 10, 11,   2012 09 03 , http://jglobal.jst.go.jp/public/201202281571194151
  • 非鉄精錬ダスト中インジウムのキレート抽出機構の推定, 澤井光, 中野俊宏, LU Chao, 牧輝弥, 水谷聡, 長谷川浩, 高分子学会北陸支部研究発表講演会講演要旨集, 61st, 45,   2012 , http://jglobal.jst.go.jp/public/201302216935794240
  • モデルセシウム汚染土壌の化学的除染法に関する基礎検討, LU Chao, 澤井光, 牧輝弥, 水谷聡, 長谷川浩, 高分子学会北陸支部研究発表講演会講演要旨集, 61st, 50,   2012 , http://jglobal.jst.go.jp/public/201302287255132719
  • 水溶性キレート錯体形成を利用した廃棄物中レアメタルの抽出分離, 江川侑志, 澤井光, 村瀬龍太, 牧輝弥, 水谷聡, 長谷川浩, 日本分析化学会年会講演要旨集, 60th, 106,   2011 08 31 , http://jglobal.jst.go.jp/public/201102203032669008
  • 非鉄精錬ダストに含まれるレアメタルの化学的抽出法の開発, 澤井光, 江川侑志, 村瀬龍太, 牧輝弥, 水谷聡, 長谷川浩, 日本分析化学会年会講演要旨集, 60th, 368,   2011 08 31 , http://jglobal.jst.go.jp/public/201102216570222280
  • Indium collection of ITO glass by chelate extraction with applies microwave irradiation, Egawa Yuji, Murase Ryuta, Sawai Hikaru, Maki Teruya, Mizutani Satoshi, Hasegawa Hirosi, Proceedings of the Annual Conference of Japan Society of Material Cycles and Waste Management, 22, 0, 98, 98,   2011 , 10.14912/jsmcwm.22.0.98.0, http://ci.nii.ac.jp/naid/130004631795
    Summary:現在、インジウムのリサイクルには、酸による溶出法が用いられているが、酸廃液による環境負荷などが問題となっている。本研究では、水溶性キレート剤により、廃棄物中から抽出困難なインジウム化合物を水溶性錯体として、溶出させることが可能であることに着目した。本法は弱酸性から弱アルカリ性のpH領域で抽出可能であるため低環境負荷であり、キレート剤を選択することで廃棄物中の様々なレアメタルの回収に適用可能な汎用性のある技術として有望である。水溶性キレート剤を主成分とする抽出液を廃ITOガラスに適用し、試料の過熱、粉砕等の反応条件を検討した結果、100℃以上の反応温度およびマイクロ波照射の適用により高効率でのインジウム抽出が可能であることが明らかになった。
  • A165 Microorganisms and DNA concentration in the atmosphere over Noto peninsula, 98, 0,   2010 09 30 , http://ci.nii.ac.jp/naid/110007983163
  • Problem-Based Learning in the Laboratory Course in Physical, Inorganic, and Analytical Chemistry, HASEGAWA Hiroshi, YAMAGUCHI Takahiro, OHTA Akio, MAKI Teruya, Journal of JSEE, 53, 1, 105, 108,   2005 01 20 , 10.4307/jsee.53.105, http://ci.nii.ac.jp/naid/10014302899
    Summary:Although the method of problem-based learning is remarkably effective for engineering education, it is difficult to apply to a curriculum of chemistry education. In this paper, we described a new problem-based learning system of chemistry experiments for the laboratory course of the chemistry and chemical engineering department. This system consists of three individual subjects of inorganic chemistry experiments ; Physical Chemistry, Inorganic Chemistry and Analytical Chemistry. Each subject shares the objects of education for problem-based learning. Students carry out some theme of exper-iments and present the results during each period repeatedly. This system enables to study a series of methods for creative research as well as the fundamental skills and knowledge in each field of chemistry in the same program.
  • (181)Problem-Based Learning in the Department of Applied Chemistry:: Laboratory Course in Physical, Inorganic, and Analytical Chemistry, HASEGAWA Hiroshi, YAMAGUCHI Takahiro, OHTA Akio, MAKI Teruya, Proceedings of Annual Conference of Japanese Society for Engineering Education, 2004, 0, 359, 360,   2004 , http://ci.nii.ac.jp/naid/110007464724
  • Phytotoxicity of Arsenate and Salinity on Early Seedling Growth of Rice (Oryza sativa L.): A Threat to Sustainable Rice Cultivation in South and South-East Asia, M. Mamunur Rahman, M. Azizur Rahman, T. Maki, H. Hasegawa, BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY, 88, 5, 695, 702,   2012 05 , 10.1007/s00128-012-0580-4, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84861312937&origin=inward
    Summary:Arsenic (As) contamination is an important environmental consequence in some parts of salinity-affected South (S) and South-East (SE) Asia. In this study, we investigated the individual and combined phytotoxicity of arsenic (As) [arsenate; As(V)] and salinity (NaCl) on early seedling growth (ESG) of saline-tolerant and non-tolerant rice varieties. Germination percentage (GP), germination speed (GS) and vigor index (VI) of both saline-tolerant and non-tolerant rice varieties decreased significantly (p > 0.01) with increasing As(V) and NaCl concentrations. The highest GP (91%) was observed for saline non-tolerant BRRI dhan28 and BRRI dhan49, while the lowest (62%) was for saline-tolerant BRRI dhan47. The ESG parameters, such as weights and relative lengths of plumule and radicle, also decreased significantly (p < 0.01) with increasing As(V) and NaCl concentrations. Relative radicle length was more affected than plumule length by As(V) and NaCl. Although VI of saline-tolerant and non-tolerant rice seedlings showed significant variation (p < 0.05), weights and lengths of plumule and radicle of different rice varieties did not show significant variation for As(V) and NaCl treatments. Results reveal that the combined phytotoxicity of As(V) and NaCl on rice seed germination and ESG are greater than their individual toxicities, and some saline-tolerant rice varieties are more resistant to the combined phytotoxicity of As(V) and NaCl than the saline non-tolerant varieties.
  • Erratum: Selective separation of some ecotoxic transition metal ions from aqueous solutions using immobilized macrocyclic material containing solid phase extraction system (Central European Journal of Chemistry (2011) 9:6 (1019-1026)), Ismail M.M. Rahman, Yoshiaki Furusho, Zinnat A. Begum, Akhmad Sabarudin, Shoji Motomizu, Teruya Maki, Hiroshi Hasegawa, Central European Journal of Chemistry, 10, 1, 277,   2012 02 , 10.2478/s11532-011-0111-x, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=83555174702&origin=inward
  • The significance of biodegradable methylglycinediacetic acid (MGDA) for iron and arsenic bioavailability and uptake in rice plant, M. Azizur Rahman, M. Mamunur Rahman, T. Maki, H. Hasegawa, SOIL SCIENCE AND PLANT NUTRITION, 58, 5, 627, 636,   2012 , 10.1080/00380768.2012.717246, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84869775488&origin=inward
    Summary:Methylglycinediacetic acid (MGDA) is a readily biodegradable complexing agent in compliance with Organization for Economic Cooperation and Development standards. In the present study, the use of MGDA for iron (Fe) and arsenic (As) bioavailability and uptake by rice plants (Oryza sativa L.) was investigated. The highest plant biomass was observed at pH 7, and the growth of rice seedlings decreased significantly (p < 0.05) with increasing pH of the nutrient solution. This might be due to Fe deficiency to the plant at alkaline pH. When rice seedlings were grown with different concentrations of MGDA (0.1, 0.25, 0.5, 1.0, 2.5, and 5 mM), the highest plant biomass was observed at 0.25 mM MGDA, while further increases of the ligand concentration decreased the plant growth. Fe concentrations on rice root surfaces decreased gradually with increasing MGDA concentrations in the growing medium, while Fe concentrations in rice roots and shoots increased with increasing MGDA concentrations up to 0.25mM and then decreased gradually. This indicates that the concentration of the chelating ligand influences Fe uptake in the plant. Arsenic concentrations on rice root surfaces decreased, while As concentrations in roots and shoots increased with the addition of MGDA in the growing medium, indicating that the ligand enhanced As bioavailability and uptake in rice. The mechanism behind the MGDA effect on Fe and As uptake in plant is likely to be due to that Fe exists mostly in insoluble particulate forms [e. g., ferric oxide (Fe2O3), ferric hydroxide (Fe(OH)(3)) and ferric oxyhydroxide (FeOOH)] at neutral or alkaline pH, and the soluble [e.g., ferric ion (Fe3+), iron hydroxide ion (Fe(OH)(2+)) and iron dihydroxide ion (Fe(OH)(2)(+))] and apparently soluble (colloidal) fractions of Fe are increased at moderate concentrations of the ligand that increases Fe bioavailability. Since arsenate [As(V)] binds to the insoluble Fe-oxides/hydroxides, the binding sites for As(V) decreases with the increase of the soluble fractions of Fe by the ligand, which slightly increased As uptake in rice plants.
  • Effect of external iron and arsenic species on chelant-enhanced iron bioavailability and arsenic uptake in rice (Oryza sativa L.), M. Azizur Rahman, M. Mamunur Rahman, K. Kadohashi, T. Maki, H. Hasegawa, CHEMOSPHERE, 84, 4, 439, 445,   2011 07 , 10.1016/j.chemosphere.2011.03.046, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=79958748978&origin=inward
    Summary:This study was conducted to investigate the effect of external iron status and arsenic species on chelant-enhanced iron bioavailability and arsenic uptake. Rice seedlings (Oryza sativa L) were used as model plant, and were grown in artificially contaminated sandy soils irrigated with Murashige and Skoog (MS) culture solution. Arsenate uptake in roots and shoots of rice seedlings were affected significantly (p > 0.05) while dimethylarsinic acid (DMAA) was not by the additional iron and chelating ligand treatments. Regardless of iron concentrations in the soil solution, HIDS increased arsenic uptake for roots more than EDTA and EDDS. Chelating ligands and arsenic species also influenced iron uptake in rice roots. Irrespective of arsenic species, HIDS was found to be more effective in the increase of iron bioavailability and uptake in rice roots compared to other chelants. There was a significant positive correlation (r = 0.78, p < 0.05) between arsenate and iron concentrations in the roots of rice seedlings grown with or without additional iron indicating that arsenate inhibit iron uptake. In contrast, there was no correlation between iron and DMAA uptake in roots. Poor correlation between iron and arsenic in shoots indicated that iron uptake in shoots was neither affected by additional iron nor by arsenic species. Compared to the control, chelating ligands increased iron uptake in shoots of rice seedlings significantly (p < 0.05). Regardless of additional iron and arsenic species, iron uptake in rice shoots did not differed among EDTA. EDDS, and HIDS treatments. (C) 2011 Elsevier Ltd. All rights reserved.
  • Size fractionation of iron compounds in phytoplankton cultures in the presence of chelating ligands, C Okumura, H Hasegawa, H Mizumoto, T Maki, K Ueda, BUNSEKI KAGAKU, 53, 11, 1215, 1221,   2004 11 , 10.2116/bunsekikagaku.53.1215, https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=12144251388&origin=inward
    Summary:We determined iron speciation in laboratory cultures containing a radioactive tracer, Fe, and chelating ligands using a size-fractionation method. For the size-fractionation of iron, filters with 0.025, 0.20 and 3.0 mum pore size were used. In the media with chelating ligands, major species of iron were colloidal and truly dissolved fractions. When cells of phytoplankton were added, the colloidal fractions decreased, while the large particle fractions (> 3.0 mum) increased in the cultures. The iron uptake of phytoplankton, especially extracellular iron, was correlated with the colloidal iron fractions, of which the concentrations depended on the chelating ligands in the media. It is likely that phytoplankton absorbed the colloidal iron fractions onto the cell surface and that utilized the fractions as an iron source in the cultivated media.
  • Detection of bacterial population contributing to organoarsenic decomposition, T Maki, H Hasegawa, S Wachi, K Ueda, GEOCHIMICA ET COSMOCHIMICA ACTA, 67, 18, A269, A269,   2003 09

Awards & Honors

  •   2006 04 01 , Nissan Science Foundation
  •   2006 04 01 , Salt Science Research Foundation
  •   2005 04 01 , Nissan Science Foundation
  •   2004 04 01 , Salt Science Research Foundation