詳細

石丸　恵 （イシマル　メグミ）

  • 生物理工学部 食品安全工学科　教授/生物工学専攻主任
Last Updated :2024/04/25

コミュニケーション情報 byコメンテータガイド

  • コメント

    青果物の収穫後から消費者に届くまでの品質変化や品質制御技術について研究しています。特に、果実の軟化について、細胞壁の分解・再構築に関連する酵素について研究を進めています。

研究者情報

学位

  • 博士(農学)

ホームページURL

J-Global ID

プロフィール

  • 果実の成熟過程および収穫後の軟化機構に興味をもち，植物細胞壁や細胞壁分解酵素について基礎および応用の研究を進めています．

研究キーワード

  • 細胞壁   細胞壁分解酵素   構造解析   ベレゾーン   基質特異性   組換えタンパク   園芸利用   果実軟化   ブドウ   軟化   ストレス反応   園芸利用学   貯蔵技術   品質保持   

現在の研究分野（キーワード）

    青果物の収穫後から消費者に届くまでの品質変化や品質制御技術について研究しています。特に、果実の軟化について、細胞壁の分解・再構築に関連する酵素について研究を進めています。

研究分野

  • 環境・農学 / 園芸科学

経歴

  • 2020年04月 - 現在  近畿大学生物理工学部 食品安全工学科教授

学歴

  •         - 1999年   大阪府立大学   農学研究科   園芸農学

所属学協会

  • 日本応用糖質科学会   日本食品保蔵科学会   日本植物生理学会   園芸学会   

研究活動情報

論文

  • Kaori Matsuyama; Tatsuya Kondo; Kiyohiko Igarashi; Tatsuji Sakamoto; Megumi Ishimaru
    Planta 252 4 72 - 72 2020年10月 [査読有り]
     
    MAIN CONCLUSION: TBG4 recognize multiple linkage types substrates due to having a spatially wide subsite + 1. This feature allows the degradation of AGI, AGII, and AGP leading to the fruit ripening. β-galactosidase (EC 3. 2. 1. 23) catalyzes the hydrolysis of β-galactan and release of D-galactose. Tomato has at least 17 β-galactosidases (TBGs), of which, TBG 4 is responsible for fruit ripening. TBG4 hydrolyzes not only β-1,4-bound galactans, but also β-1,3- and β-1,6-galactans. In this study, we compared each enzyme-substrate complex using X-ray crystallography, ensemble refinement, and docking simulation to understand the broad substrate-specificity of TBG4. In subsite - 1, most interactions were conserved across each linkage type of galactobioses; however, some differences were seen in subsite + 1, owing to the huge volume of catalytic pocket. In addition to this, docking simulation indicated TBG4 to possibly have more positive subsites to recognize and hydrolyze longer galactans. Taken together, our results indicated that during tomato fruit ripening, TBG4 plays an important role by degrading arabinogalactan I (AGI), arabinogalactan II (AGII), and the carbohydrate moiety of arabinogalactan protein (AGP).
  • Tatsuya Kondo; Yuichi Nishimura; Kaori Matsuyama; Megumi Ishimaru; Masami Nakazawa; Mitsuhiro Ueda; Tatsuji Sakamoto
    Applied Microbiology and Biotechnology 104 3 1135 - 1148 2020年02月 [査読有り]
     
    Three recombinant β-galactosidases (BGALs; PcBGAL35A, PcBGAL35B, and PcGALX35C) belonging to the glycoside hydrolase (GH) family 35 derived from Penicillium chrysogenum 31B were expressed using Pichia pastoris and characterized. PcBGAL35A showed a unique substrate specificity that has not been reported so far. Based on the results of enzymological tests and 1H-nuclear magnetic resonance, PcBGAL35A was found to hydrolyze β-1,4-galactosyl residues linked to L-rhamnose in rhamnogalacturonan-I (RG-I) of pectin, as well as p-nitrophenyl-β-D-galactopyranoside and β-D-galactosyl oligosaccharides. PcBGAL35B was determined to be a common BGAL through molecular phylogenetic tree and substrate specificity analysis. PcGALX35C was found to have similar catalytic capacities for the β-1,4-galactosyl oligomer and polymer. Furthermore, PcGALX35C hydrolyzed RG-I-linked β-1,4-galactosyl oligosaccharide side chains with a degree of polymerization of 2 or higher in pectin. The amino acid sequence similarity of PcBGAL35A was approximately 30% with most GH35 BGALs, whose enzymatic properties have been characterized. The amino acid sequence of PcBGAL35B was approximately 80% identical to those of BGALs from Penicillium sp. The amino acid sequence of PcGALX35C was classified into the same phylogenetic group as PcBGAL35A. Pfam analysis revealed that the three BGALs had five domains including a catalytic domain. Our findings suggest that PcBGAL35A and PcGALX35C are enzymes involved in the degradation of galactosylated RG-I in pectin. The enzymes characterized in this study may be applied for products that require pectin processing and for the structural analysis of pectin.
  • 温風処理がブルーベリー果実の貯蔵中の品質に及ぼす影響
    松山佳織; 伴 琢也; 石丸 恵
    日本食品保蔵科学会誌 45 4 169 - 174 2019年07月 [査読有り]
  • Fraidoon Karimi; Takashi Baba; Satoshi Noma; Daiki Mizuta; Jin Gook Kim; Manabu Watanabe; Megumi Ishimaru; Takuya Ban
    The Horticulture Journal 88 3 315 - 319 2019年 [査読有り]
  • Masahiro Eda; Takashi Matsumoto; Tatsuji Sakamoto; Megumi Ishimaru; Toshiji Tada
    The Plant Journal 86 4 300 - 307 2016年05月 [査読有り]
     
    Plant -galactosidases hydrolyze cell wall -(1,4)-galactans to play important roles in cell wall expansion and degradation, and turnover of signaling molecules, during ripening. Tomato -galactosidase4 (TBG4) is an enzyme responsible for fruit softening through the degradation of -(1,4)-galactan in the pericarp cell wall. TBG4 is the only enzyme among TBGs1-7 that belongs to the -galactosidase/exo--(1,4)-galactanase subfamily. The enzyme can hydrolyze a wide range of plant-derived (1,4)- or 4-linked polysaccharides, and shows a strong ability to attack -(1,4)-galactan. To gain structural insight into its substrate specificity, we determined crystal structures of TBG4 and its complex with -d-galactose. TBG4 comprises a catalytic TIM barrel domain followed by three -sandwich domains. Three aromatic residues in the catalytic site that are thought to be important for substrate specificity are conserved in GH35 -galactosidases derived from bacteria, fungi and animals; however, the crystal structures of TBG4 revealed that the enzyme has a valine residue (V548) replacing one of the conserved aromatic residues. The V548W mutant of TBG4 showed a roughly sixfold increase in activity towards -(1,6)-galactobiose, and similar to 0.6-fold activity towards -(1,4)-galactobiose, compared with wild-type TBG4. Amino acid residues corresponding to V548 of TBG4 thus appear to determine the substrate specificities of plant -galactosidases towards -1,4 and -1,6 linkages. Significance Statement Tomato -galactosidases (TBG1-TBG7) in the glycosyl hydrolase 35 (GH35) family are thought to play important roles during fruit development and maturation. Here we report the crystal structure of TBG4 in complex with its substrate.
  • Eda M; Ishimaru M; Tada T
    Acta crystallographica. Section F, Structural biology communications 71 Pt 2 153 - 156 2015年02月 [査読有り]
     
    Plant beta-galactosidases play important roles in carbohydrate-reserve mobilization, cell-wall expansion and degradation, and turnover of signalling molecules during ripening. Tomato beta-galactosidase 4 (TBG4) not only has beta-galactosidase activity but also has exo-beta-(1,4)-galactanase activity, and prefers beta-(1,4)-galactans longer than pentamers as its substrates; most other beta-galactosidases only have the former activity. Recombinant TBG4 protein expressed in the yeast Pichia pastoris was crystallized by the sitting-drop vapour-diffusion method using PEG 10 000 as a precipitant. The crystals belonged to the orthorhombic space group P2(1)2(1)2(1), with unit-parameters a = 92.82, b = 96.30, c = 159.26 angstrom, and diffracted to 1.65 angstrom resolution. Calculation of the Matthews coefficient suggested the presence of two monomers per asymmetric unit (V-M = 2.2 angstrom(3) Da(-1)), with a solvent content of 45%.
  • H. Izumi; Y. Murakami; M. Ishimaru; Y. Ozaki
    XI INTERNATIONAL CONTROLLED AND MODIFIED ATMOSPHERE RESEARCH CONFERENCE 1071 203 - 209 2015年 [査読有り]
     
    Freshly peeled "baby persimmons", 3-4 cm in diameter and 20-25 g in weight, were prepared by enzymatic peeling of 'Totsutanenashi' cherry persimmon fruit (Diospyros kaki Thunb.), which is a bud mutation and miniature of the full size 'Hiratanenashi' persimmon. The microbiological and visual quality of enzymatically peeled baby persimmons as a fresh-cut fruit was evaluated during storage in air or high CO2 atmospheres (10, 15 and 20%) at 10 degrees C. The flesh of intact baby persimmon fruit showed counts of 2.6 log CFU/g for mesophilic aerobic bacteria and a non-detectable level for coliform groups and fungi. A hot water dipping treatment in the enzymatic peeling process reduced both the counts of mesophiles to levels below the lower limit of detection (2.4 log CFU/g) and the diversity of bacterial flora. Coliforms and fungi remained undetectable throughout the enzymatic peeling process. During storage in air, counts of mesophiles, coliforms, lactic acid bacteria, and fungi of baby persimmons increased to 4-5.5 log CFU/g by day 6, while high CO2 atmospheres reduced the microbial growth, with the greatest reduction observed in 15 or 20% CO2. Diversity of the microflora also decreased in 20% CO2 atmosphere as compared to air on day 6. High CO2 atmospheres inhibited the development of brown discoloration in baby persimmons by day 4, but all samples developed browning to an unmarketable level by day 6. These results indicate that high CO2 atmospheres of 15 to 20% are desirable for enzyme-peeled baby persimmons to extend the shelf life when stored at 10 degrees C.
  • Eda M; Ishimaru M; Tada T; Sakamoto T; Kotake T; Tsumuraya Y; Mort AJ; Gross KC
    Journal of plant physiology 171 16 1454 - 1460 2014年10月 [査読有り]
     
    The open reading frame of tomato beta-galactosidase 1 was expressed in yeast, and the enzymatic properties and substrate specificity were investigated. The enzyme had peak activity at pH 5.0 and 40-50 degrees C. TBG1 was active on beta-(1,3)- and beta-(1,6)-galactobiose and lactose. TBG1 released galactose from lupin galactan, tomato fruit alkali soluble pectin, arabinogalactan, gum arabic and methyl beta-(1,6)-galactohexaoside, but not from labeled beta-(1,4)-galactoheptaose. TBG1 was assessed for its ability to degrade three galactosyl-containing cell wall fractions purified from different development and ripening stages of tomato fruit. TBG1 released galactose from all of the fractions from all of the stages tested. TBG1 activity was highest on the hemicellulose fraction at the 10 and 20 d after pollination stage. This result is not correlated the with TBG1 expression pattern. TBG1 might act on a small but specific set of polysaccharide containing galactose. (C) 2014 Elsevier GmbH. All rights reserved.
  • Tatsuji Sakamoto; Megumi Ishimaru
    APPLIED MICROBIOLOGY AND BIOTECHNOLOGY 97 12 5201 - 5213 2013年06月 [査読有り]
     
    Arabinogalactans (AGs) are branched galactans to which arabinose residues are bound as side chains and are widely distributed in plant cell walls. They can be grouped into two types based on the structures of their backbones. Type I AGs have beta-1,4-galactan backbones and are often covalently linked to the rhamnogalacturonan-I region of pectins. Type II AGs have beta-1,3-galactan backbones and are often covalently linked to proteins. The main enzymes involved in the degradation of AGs are endo-beta-galactanases, exo-beta-galactanases, and beta-galactosidases, although other enzymes such as alpha-l-arabinofuranosidases, beta-l-arabinopyranosidases, and beta-d-glucuronidases are required to remove the side chains for efficient degradation of the polysaccharides. Galactanolytic enzymes have a wide variety of potential uses, including the bioconversion of AGs to fermentable sugars for production of commodity chemicals like ethanol, biobleaching of cellulose pulp, modulation of pectin properties, improving animal feed, and determining the chemical structure of AGs. This review summarizes our current knowledge about the biochemical properties and potential applications of AG-degrading enzymes.
  • Tatsuji Sakamoto; Hiromasa Tanaka; Yuichi Nishimura; Naoya Kasai; 石丸 恵
    Applied Microbiology and Biotechnology 90 5 1701 - 1710 Springer 2011年06月 [査読有り]
     
    A type II arabinogalactan-degrading enzyme, termed Exo-1,3-Gal, was purified to homogeneity from the culture filtrate of Sphingomonas sp. 24T. It has an apparent molecular mass of 48 kDa by SDS-PAGE. Exo-1,3-Gal was stable from pH 3 to 10 and at temperatures up to 40 A degrees C. The optimum pH and temperature for enzyme activity were pH 6 to 7 and 50 A degrees C, respectively. Galactose was released from beta-1,3-d-galactan and beta-1,3-d-galactooligosaccharides by the action of Exo-1,3-Gal, indicating that the enzyme was an exo-beta-1,3-d-galactanase. Analysis of the reaction products of beta-1,3-galactotriose by high-performance anion-exchange chromatography revealed that the enzyme hydrolyzed the substrate in a non-processive mode. Exo-1,3-Gal bypassed the branching points of beta-1,3-galactan backbones in larch wood arabinogalactan (LWAG) to produce mainly galactose, beta-1,6-galactobiose, and unidentified oligosaccharides 1 and 2 with the molar ratios of 7:19:62:12. Oligosaccharides 1 and 2 were enzymatically determined to be beta-1,6-galactotriose and beta-1,6-galactotriose substituted with a single arabinofuranose residue, respectively. The ratio of side chains enzymatically released from LWAG was in good agreement with the postulated structure of the polysaccharide previously determined by chemical methods.
  • Tatsuji Sakamoto; Hiromasa Tanaka; Yuichi Nishimura; Megumi Ishimaru; Naoya Kasai
    Appl Microbiol Biotechnol. 90 5 1701 - 1710 2011年06月 [査読有り]
     
    A type II arabinogalactan-degrading enzyme, termed Exo-1,3-Gal, was purified to homogeneity from the culture filtrate of Sphingomonas sp. 24T. It has an apparent molecular mass of 48 kDa by SDS-PAGE. Exo-1,3-Gal was stable from pH 3 to 10 and at temperatures up to 40 A degrees C. The optimum pH and temperature for enzyme activity were pH 6 to 7 and 50 A degrees C, respectively. Galactose was released from beta-1,3-d-galactan and beta-1,3-d-galactooligosaccharides by the action of Exo-1,3-Gal, indicating that the enzyme was an exo-beta-1,3-d-galactanase. Analysis of the reaction products of beta-1,3-galactotriose by high-performance anion-exchange chromatography revealed that the enzyme hydrolyzed the substrate in a non-processive mode. Exo-1,3-Gal bypassed the branching points of beta-1,3-galactan backbones in larch wood arabinogalactan (LWAG) to produce mainly galactose, beta-1,6-galactobiose, and unidentified oligosaccharides 1 and 2 with the molar ratios of 7:19:62:12. Oligosaccharides 1 and 2 were enzymatically determined to be beta-1,6-galactotriose and beta-1,6-galactotriose substituted with a single arabinofuranose residue, respectively. The ratio of side chains enzymatically released from LWAG was in good agreement with the postulated structure of the polysaccharide previously determined by chemical methods.
  • Changes in inner contents of ‘Kyoho’ grape berry during the growth and ripening period.
    T. Ban; A. Nakatsuka; K. Akaura; S. Matsumoto; M. Ishimaru; H. Itamura
    Applied Horticulture 12 93 - 96 2010年12月 [査読有り]
  • Megumi Ishimaru; David L. Smith; Andrew J. Mort; Kenneth C. Gross
    PLANTA 229 2 447 - 456 2009年01月 [査読有り]
     
    The open reading frames of tomato beta-galactosidase (TBG) 4 and 5 cDNAs were expressed in yeast, and the enzymes properties and substrate specificities were investigated. The two enzymes had peak activities between pH 4-4.5 and 37-45A degrees C. TBG4 specifically hydrolyzed beta-(1 -> 4) and 4-linked galactooligosaccharides. TBG5 had a strong preference to hydrolyze beta-(1 -> 3) and beta-(1 -> 6)-linked galactooligosaccharides. Exo-beta-galactanase activity of the TBG enzymes was measured by determining the release of galactosyl residues from native tomato cell wall fractions throughout fruit development and ripening. Both TBGs released galactose from all of the fractions and stages tested. TBG4 activity was highest using chelator soluble pectin and alkali soluble pectin at the turning stage of ripening. Using aminopyrene trisulfonate labeled substrates, TBG4 was the only enzyme with strong exo-beta-(1 -> 4)-galactanase activity on 5 mer or greater galactans. TBG4 and TBG5 were both able to degrade galactosylated rhamnogalacturonan. Neither enzyme was able to degrade galactosylated xyloglucan.
  • Yoshiko Koshita; Shozo Kobayashi; Megumi Ishimaru; Yoshio Funamoto; Mikio Shiraishi; Akifumi Azuma; Hiroshi Yakushiji; Masayoshi Nakayama
    JOURNAL OF THE JAPANESE SOCIETY FOR HORTICULTURAL SCIENCE 77 1 33 - 37 2008年01月 
    A cDNA, VlmybA1-2, for an anthocyanin regulatory gene of grape was constructed under the control of the cauliflower mosaic virus (CaMV) 35SRNA promoter and introduced into leaf disks and petioles of kiwifruit (Actinidia deliciosa) plants by Agrobacterium-mediated gene transfer. When the tissues were cultured on selection medium, red cells visible to the naked eye formed at the cut ends of the segments after approximately 2 weeks. The cells developed into calluses, adventitious buds, and reddish-purple plantlets after 2, 3, and 6 months of culture, respectively. The pigment produced in the leaves of the transformed plants was determined to be cyanidin 3-O-(2-O-beta-xylosyl)-beta-glucoside (cyanidin 3-O-sambubioside). As VlmybA1-2 can also produce red cells in tomato and eggplant, it may be useful as a visible marker to confirm efficient transformation in dicots.
  • Megumi Ishimaru; David L. Smith; Kenneth C. Gross; Shozo Kobayashi
    JOURNAL OF PLANT PHYSIOLOGY 164 12 1675 - 1682 2007年12月 [査読有り]
     
    Expansins are cell-wall-localized proteins that induce Loosening of isolated plant cell walls in vitro in a pH-dependent manner, but exhibit no detectable hydrolase or transglycosylase activity. Three putative expansin cDNAs, Vlexp1, Vlexp2, and Vlexp3 were isolated from a cDNA library made from mature berries of the Kyoho grape. Expression profiles of the 3 genes were analyzed throughout berry development. Accumulation of the Vlexp3 transcript was closely correlated with berry softening, and expression of this gene was detected before veraison and markedly increased at veraison (onset of berry softening). Expression of Vlexp3 was berry-specific. Vlexp1 and Vlexp2 mRNA accumulation began during the expansion stage of berry development and expression increased for both genes during ripening. Vlexp1 and Vlexp2 mRNA was detected in Leaf, tendril and flower tissues and Vlexp2 mRNA was additionally detected in root and seed tissues. These findings suggest that the three expansin genes are associated with cell division or expansion and berry ripening. Vlexp3, in particular, is most likely to play a rote in grape berry softening at veraison. (C) 2006 Elsevier GmbH. All rights reserved.
  • Yoshihiro Imahori; Yoshitaka Suzuki; Minako Kawagishi; Megumi Ishimaru; Yoshinori Ueda; Kazuo Chachin
    POSTHARVEST BIOLOGY AND TECHNOLOGY 46 2 160 - 166 2007年11月 
    Harvested leaves of Chinese chives were stored in air + 10, 20 or 30% CO2, or air for 7 days at 20 degrees C to determine the effects of CO(2-)enriched atmospheres on their physiology and quality. Leaf yellowing was visible at day 5 in air, whereas CO, enrichment delayed yellowing and retarded chlorophyll and protein degradation that accompanied leaf senescence. At 30% CO2, undesirable off-odors were induced, presumably due to accumulation of ethanol in the tissue. The ethanol contents did not change during storage in leaves exposed to 10 or 20% CO2, or air, while the content in leaves exposed to 30% CO2 significantly increased. However, CO2 enrichment did not significantly influence acetaldehyde concentrations for the leaves. Alcohol dehydrogenase (ADH) activity increased in leaves exposed to 10 or 20% CO2, while its activity in leaves exposed to 30% CO2, was slightly higher than that of the control. Succinate dehydrogenase (SDH) activity greatly decreased in leaves exposed to 30% CO2, while its activity in leaves exposed to 10 or 20% CO2 only decreased slightly. The content of pyruvate increased in leaves exposed to 30% CO2, while its concentration in leaves exposed to 10 or 20% CO2, was slightly higher than that of the controls. Thus, our results indicate that it would be necessary to keep Chinese chives at 20 degrees C because of a lack of refrigeration in the distribution system, or in a modified atmosphere package designed to develop an optimum atmosphere during retail display, and suggest a potential for using CO2-enriched atmospheres at higher temperatures to help maintain quality. (C) 2007 Elsevier B.V. All rights reserved.
  • Yoshihiro Imahori; Izumi Kishioka; Kazuko Uemura; Eiichi Makita; Hitomi Fujiwara; Yuka Nishiyama; Megumi Ishimaru; Yoshinori Ueda; Kazuo Chachin
    JOURNAL OF THE JAPANESE SOCIETY FOR HORTICULTURAL SCIENCE 76 3 258 - 265 2007年07月 
    Sweetpotato roots were stored under a continuous flow of 0% or 1% O-2 (balance N-2) or air for 7 days at 20 degrees C to study the effects of short-term exposure to low OZ on their physiological responses and quality. During the course of the experiment, no visible signs of injury or decay were observed. However, low OZ treatments increased the soluble solid content and weak off-odors were detected by olfactory evaluation in roots stored at 0%O-2. The intensity of off-odors increased as the concentrations of acetaldehyde and ethanol increased in roots during storage. Ethanol concentrations were higher than those of acetaldehyde, which remained low during storage in 1% O-2 and air, but increased greatly in roots stored at 0% O-2. Pyruvate decarboxylase (PDC) activities in roots exposed to 0% or 1% OZ increased by 3.1- and 2-fold respectively over levels in roots stored in air by day 7. Alcohol dehydrogenase (ADH) activities in roots exposed to 0% or 1% OZ increased by 1.6- and 1.7-fold respectively over levels in roots stored in air by day 7. ADH-specific activity was about 10-times that of PDC. The pH of root homogenate exposed to air remained constant, whereas the pH increased and decreased, respectively, in roots stored at 0% or 1 % O-2. PDC showed stability over the pH range 5.5-7.0, whereas ADH exhibited stability over the pH range 6.0-7.5. The Km of PDC in sweetpotato was 0.56 mM for pyruvate, whereas the Km of ADH was 0.19 mM for acetaldehyde. From these results, there may be some potential for the short-term exposure of sweetpotato roots to low 02 in place of low temperature treatment to prolong shelf-life, although ethanol fermentation may be accelerated under low OZ atmospheres.
  • 石丸 恵
    日本食品保蔵科学会誌 33 2 77 - 83 日本食品保蔵科学会 2007年03月 
    高等植物の形と大きさをもっとも直接的に決めているのは細胞壁である。細胞膜の外側に位置し植物細胞の最外層を構成する細胞壁はかつて後形質と呼ばれ、死んだ成分として扱われてきた。しかし、現在では細胞壁が、多くの酵素が活動する活発な代謝の場であることが明らかになってきた。細胞壁はその性質を絶え間なくダイナミックに変化させ、形態形成や生長調節ばかりでなく、ほかの生命活動の調節においても重要な役割を果たしていることが明らかになってきた。細胞壁を構成するさまざまな成分は、ほかの細胞成分と同様に遺伝情報に基づいて合成・分解されている。しかし、高等植物の場合、遺伝的プログラムは周囲の環境によって強く修飾されやすい。これは進化上、固着生活を選択した植物にとって宿命ともいえる特徴であり、植物は動物以上に敏感で精密な環境応答機構を備えている。ここでは、果実特にブドウ果実とトマト果実の細胞壁分解関連酵素の遺伝子およびタンパクに注目し、細胞壁の構造と代謝やそれらに対する酵素タンパクの作用に的を絞り言及していきたい。
  • Sumithra K. Wendakoon; Yoshinori Ueda; Yoshihiro Imahori; Megumi Ishimaru
    Journal of the Science of Food and Agriculture 86 13 2241  2006年10月 [査読有り]
  • Sumithra K. Wendakoon; Yoshinori Ueda; Yoshihiro Imahori; Megumi Ishimaru
    JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 86 10 1475 - 1480 2006年08月 
    Yellow, ripened (yellow with green tips) bananas were treated with nitrogen gas for 12, 24 and 48 h at 20 degrees C to study the effects of anaerobic conditions on the fruit quality, including the production of volatile compounds and activity of alcohol acetyltransferase (AAT) during the post-harvest period. Significantly higher concentrations of acetaldehyde and ethanol were found in the treated fruit than in the untreated bananas after removal from the conditions. The 48-h treatment showed higher levels of ethanol and acetaldehyde after storage. Immediately after releasing the fruit from the anaerobic atmosphere, the amounts of isobutyl acetate and isoamyl acetate decreased. The production of ethyl acetate increased markedly in each treatment unit 1 day after removing the fruit. Regardless of recovery from the production of isobutyl acetate and isoamyl acetate 1 day after treatment, the banana-like aroma was denatured because of the production of high levels of ethyl acetate and ethanol. The increase in AAT was slightly lower in nitrogen-treated fruit than untreated fruit. However, the activity in treated fruit was sufficient for ester production in bananas. The endogenous alcohol levels were increased during nitrogen gas treatment in the fruit due to the inhibition of ester production. Colour development of the bananas was greatly inhibited by the treatments, while the sugar content did not show any differences between the treated and untreated fruit. The results suggest that, even if bananas are removed from the short-term anaerobic conditions, a loss in quality, except sweetness, easily occurs afterwards, especially the characteristic aroma of the fruit during the post-harvest period. (c) 2006 Society of Chemical Industry.
  • V. Srilaong; Y. Tatsumi; M. Ishimaru
    PROCEEDINGS OF THE IVTH INTERNATIONAL CONFERENCE ON MANAGING QUALITY IN CHAINS, VOLS 1 AND 2 712 712 661 - + 2006年 
    Respiratory pattern and succinate dehydrogenase (SDH) activity in cucumber fruit stored in 5%, 21% (air control) and 100% O-2 at 5 degrees C were studied. Storage in 100% O-2 at 5 degrees C was most effective for suppressing the respiratory rate in cucumber fruit, the rate being lower than in fruit stored in either 5% O-2 or air. Relative activity of SDH in cucumber fruit stored in 100% O-2 was lower than in other storage conditions. Only slightly different SDH activity was recorded between control and 5% O-2-treated fruit. Northern hybridization with a partial cDNA of cucumber sdhB as a probe revealed a constant level of shdB gene expression during storage. These results suggesting that change of SDH is post-transcriptionally regulated.
  • Wendakoon S.K; Ueda Y; Imahori Y; Ishimaru M
    Journal of Japanese Association of Food Preservation Science 30 1 17 - 21 日本食品保蔵科学会 2004年10月 [査読有り]
     
    バナナ果肉切片および遊離果肉細胞懸濁液に, ピルビン酸, 酢酸, クエン酸, アルコール, 補酵素等を添加し, 生成されるアセテートエステルを測定した。ピルビン酸添加では濃度が高くなると生成される酢酸エステルの量は増加した。遊離果肉細胞ではATP, CoA, Mgを添加したときに酢酸エステルの増加がみられた。TCAサイクルを促進する基質や補酵素等の添加がエステル生成を高めた。以上の結果より, 酢酸エステルの残酸基が主にピルビン酸から酢酸を経て供給されていることが明らかになった。またクエン酸からもアセチルCoAが少量供給されていると推定された。
  • M Ishimaru; K Kagoroku; K Chachin; Y Imahori; Y Ueda
    SCIENTIA HORTICULTURAE 101 1-2 1 - 10 2004年05月 [査読有り]
     
    Polyethylene film and corrugated cardboard were used to package and store burdock roots (Arctium lappa L.) at 2, 8, and 20degreesC in an attempt to maintain the good appearance of heat-processed burdock sticks. The weight loss was as high as 60% of fresh weight when corrugated cardboard cartons were used for storage at 20degreesC. However, polyethylene bag packaging or low temperature storage resulted in lower levels of weight loss (less than 30%). To control the formation of white solids in exudate from processed sticks, low temperatures (2 degreesC) and storage of burdock roots for more than 30 days before processing were used to maintain the good appearance of burdock sticks. There was a significant decline in sugar content during storage at 8 and 20 degreesC, corresponding to an increased production of white solids. The fructan composition of raw burdock roots decreased faster to about 60% after storage for 30 days at 2 degreesC than at other storage temperatures (to about 30%). Inulinase activity in burdock roots stored at 2 degreesC was higher than in those stored at 8 and 20 degreesC. The amount of muddy exudate and the sugar content in solutions surrounding burdock sticks were related to the storage temperature before processing. These results indicate that the storage of burdock roots in polyethylene film packaging for 30 days at 2 degreesC is suitable to prevent the formation of muddy precipitate in processed burdock sticks. (C) 2003 Elsevier B.V. All tights reserved.
  • SK Wendakoon; Y Ueda; Y Imahori; M Ishimaru
    JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 52 6 1615 - 1620 2004年03月 [査読有り]
     
    The effect of anaerobic conditions on acetate ester biosynthesis in ripened banana pulp was investigated. Incubation of the pulp in less than 1% O(2) resulted in a significant reduction in the formation of ethyl acetate. Regardless of the presence of a large amount of endogenous ethanol and the remaining exogenous isobutyl alcohol after complete anaerobic incubation with the pulp, the production of acetate ester decreased. The effect of addition of pyruvate, isobutyl alcohol, acetate, and methyl hexanoate on acetate ester formation in 100% N(2) was also investigated. The addition of pyruvate and isobutyl alcohol to the pulp gave lower acetate esters in N(2) than in air, whereas the pulp incubated with acetate and isobutyl alcohol produced more acetate ester in both conditions. Therefore, the lack of acetyl CoA, or more precisely acetate, in the tissue is the main reason for the inhibition of acetate ester formation under anaerobic conditions. The activity of beta-oxidation measured by incubation with methyl hexanoate was detected only in the samples incubated in air. The formation of acetyl CoA, derived from pyruvate through mitochondria and through beta-oxidation, was inhibited by anaerobic conditions, which suggests that mitochondrial activity and/or beta-oxidation are essential for ester biosynthesis.
  • 石丸 恵
    農業および園芸 78 12 1281 - 1287 養賢堂 2003年12月 [招待有り]
  • Khanom M; Ueda Y; Imahori Y; Ishimaru M; Noichinda S
    Applied Biological Science 7 2 71 - 83 大阪府立大学生物資源開発センタ- 2003年04月 [査読有り]
  • 石丸 恵; 茶珎和雄; 上田悦範
    日本食品保蔵科学会誌 29 6 323 - 327 日本食品保蔵科学会 2003年03月 [査読有り]
     
    '刀根早生'果実は, 脱渋後の肉質が柔らかく美味で生産量, 流通量共に増加している。しかしながら, '刀根早生'果実は収穫後急速に軟化することが問題となっている。そこで, 細胞壁分解酵素の一つであるβ-D-galactosidaseに注目し, 酵素の精製および特性について調査した。
    '刀根早生'果実のβ-D-galactosidaseはButyl ToyopearlとMono-SカラムによりG-I画分とG-II画分が得られ, それぞれ4.2, 38.1倍に精製され1.08, 14.6%の収率であった。G-II画分のND-PAGEにおける分子量は約120kDaであり, SDS-PAGEにおいて, 約35kDaと約46kDaの2本のバンドが確認され, β-D-galactosidaseは2つのサブユニットから構成されていると思われた。G-II画分の最適pHは5.0であり, pH 5～8でほぼ安定であった。
  • 伴 琢也; 石丸 恵; 於勢貴美子; 山口雅篤; 植田尚文
    日本食品保蔵科学会誌 29 3 153 - 157 日本食品保蔵科学会 2003年02月 [査読有り]
     
    10品種3系統のブルーベリーの生果実およびジャム中のアントシアニンを調査し, 以下の知見を得た。
    (1) 生果実中のアントシアニンについて, ハイブッシュブルーベリーで8～14種類, ラビットアイブルーベリーで8～11種類が存在した。また, アントシアニンの構成比は種および品種・系統ごとに異なった。
    (2) 供試したすべての品種・系統において, 生果実およびジャム中のアントシアニンの構成比はほとんど同一であった。
  • Relationship between volatiles and other factors indicating quality of melon (Cucumis melo cv. Prince Melon) during fruit development and storage.
    Khanom M; Ueda Y; Ishimaru M
    Scientific Report of Graduate School of Agriculture & Biological Sciences, Osaka Prefecture University 55 7 - 14 2003年01月 [査読有り]
  • 石丸 恵; 茶珎和雄; 上田悦範
    日本食品保蔵科学会誌 29 2 89 - 93 日本食品保蔵科学会 2003年01月 [査読有り]
     
    刀根早生'果実は脱渋後の肉質が緻密で柔らかく最も人気のある渋ガキ品種の一つである。'刀根早生'果実の主な脱渋方法は固形アルコールによる樹上脱渋とCO, 脱渋 (CTSD法) であり, 樹上脱渋とCO2脱渋後の軟化速度は異なっている。そこでその違いをCO2排出量とエチレン生成の変化ならびに果実の軟化に密接に関係するヘミセルロース構成糖の分解酵素の一つであるβ-D-galactosidase活性の変化から検討した。
    (1) CO2脱渋処理果実の呼吸量およびエチレン生成量は貯蔵後期に増加する傾向を示し, 樹上脱渋果実は無処理およびCO2脱渋処理果実より低く, 貯蔵期間中低いレベルを維持した。
    (2) 貯蔵期間中のβ-D-galactosidase活性は, 無処理果実およびCO2脱渋処理果実において収穫後2日から3日に活性が増大し, 収穫後7日にはその活性は収穫直後の約1.6～2倍になった。樹上脱渋果実は, 貯蔵期間中無処理およびCO2脱渋処理果実より低い活性であった。
    以上より, カキ'刀根早生'果実の収穫後の急速な軟化とβ-D-galactosidaseの活性は関係があると思われた。また, β-D-galactosidaseの活性とエチレン生成量は同様の傾向を示したことからエチレンによって誘導されたβ-D-galactosidaseがヘミセルロースを分解し, 最終的に指で押すと組織が崩壊しそうになる軟化現象を引き起こしていると思われた。
  • Y. Imahori; K. Matushita; M. Kota; Y. Ueda; M. Ishimaru; K. Chachin
    Journal of Horticultural Science and Biotechnology 78 3 386 - 393 2003年 [査読有り]
     
    Tomato fruit was stored under a continuous flow of 0% and 3% O2 (balance N2) or air for 7 d at 20°C to study the regulation of fermentative metabolism. The concentrations of ethanol and acetaldehyde were very low during storage at 3% O2 and air. At 0% O2, ethanol and to a lesser extent acetaldehyde, rapidly accumulated in the tissue. However, lactate concentration did not change during the experiment and was not significantly influenced by O2 concentration. Pyruvate decarboxylase (PDC) activity greatly increased in fruit exposed to 3% O2, while activity in fruit exposed to 0% O2 was the same level as the control. Alcohol dehydrogenase (ADH) activity greatly increased in fruit exposed to 3%, but at 0% O2 was the same level as the control. Lactate dehydrogenase (LDH) activity greatly increased in fruit exposed to 3%, but at 0% O2 was the same level as the control. The ADH activity in tomato fruit was about ten times greater than that of PDC activity and about 100 times greater than that of LDH activity during storage. Concentration of NADH in fruit exposed to 3% O2 was greater than that in fruit exposed to 0% O2 and air. Concentrations of pyruvate did not change during storage at 1% O2 and air. At 0% O2, pyruvate rapidly accumulated in its tissue. The Km of ADH in tomato fruit was 0.28 mM for acetaldehyde, and 0.058 mM for NADH. The Km of PDC in tomato fruit was 0.38 mM for pyruvate. The Km of LDH in tomato fruit was 0.18 mM for pyruvate. Possible regulation of fermentative metabolism is briefly considered.
  • T. Ban; M. Ishimaru; S. Kobayashi; S. Shiozaki; N. Goto-Yamamoto; S. Horiuchi
    Journal of Horticultural Science and Biotechnology 78 4 586 - 589 2003年 [査読有り]
     
    The effects of abscisic acid (ABA) and 2,4-dichlorophenoxyacetic acid (2,4-D) on the expression of seven anthocyanin biosynthetic pathway genes in 'Kyoho' grape berries were investigated. In untreated berries, the expression of the UDP-glucose-flavonoid: 3-O-glucosyltransferase (UFGT) gene was detected only at 42 d after full bloom (DAB), whereas the phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS), chalcone isomerase (CHI), flavanone-3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR) and leucoanthocyanidin dioxygenase (LDOX) genes were expressed throughout the growing period. ABA increased anthocyanin content in the skin and the expression of PAL, CHS, CHI, DFR and UFGT genes at 7 d after treatment. In contrast, 2,4-D inhibited the accumulation of anthocyanin and the expression of all the genes examined. The results clearly show that the anthocyanin levels resulting from the application of ABA and 2,4-D were correlated with the expression of anthocyanin biosynthetic pathway genes.
  • S Kobayashi; M Ishimaru; K Hiraoka; C Honda
    PLANTA 215 6 924 - 933 2002年10月 [査読有り]
     
    Partial cDNAs of myb-related regulatory genes were isolated from the tetraploid Kyoho grape (Vitis labruscana: V. labrusea x V. vinifera) and the expression patterns of the corresponding genes were studied. Since MybA gene expression is closely related to coloring and/or ripening of the berry (expression increases strongly with the commencement of coloring and berry softening, and is detected only in berry skin and flesh), full-length cDNAs for the gene were isolated from a mature-berry cDNA library. Three different species of MybA were identified from the cDNA sequences. Delivery of these cDNAs to somatic embryos of grape led to the induction of reddish-purple spots and UDP-glucose:flavonoid 3-O-glucosyltransferase (UFGT) gene expression in non-colored embryos. The UFGT transcript was not detected in control embryos, while other structural genes for anthocyanin biosynthesis were expressed in both control and pigmented embryos. In addition, introduction of the UFGT gene induced the same reddish-purple spots in embryos. In contrast, treatment with the leucoanthocyanidin dioxygenase (LDOX) gene failed to induce these spots. Our results strongly suggest that MybA genes are involved in the regulation of anthocyanin biosynthesis in the grape via expression of the UFGT gene.
  • 石丸 恵; 茶珎和雄; 和田安規; 上田悦範
    日本食品保蔵科学会誌 28 3 119 - 125 日本食品保蔵科学会 2002年06月 [査読有り]
     
    カキ'平核無'と'富有'果実はカキの中でも人気のある品種である。カキ'平核無'果実の軟化のメカニズムを明らかにすることと, 渋ガキと甘ガキの軟化の違いを明らかにするためCO2排出量とエチレン生成量の変化, ならびにペクチン質およびヘミセルロースの変化から調査した。
    (1) '平核無'果実の呼吸量およびエチレン生成量は収穫後'富有'果実より高い値を示したが, その後減少する傾向を示した。'富有'果実の呼吸量は貯蔵期間中ほぼ一定であった。エチレン生成は収穫後からみられなかった。
    (2) PAW可溶性画分のウロン酸量および糖量は, 両品種とも貯蔵中増加した。CDTA可溶性画分のウロン酸量および糖量は, '平核無'果実では貯蔵中変化はなかったが, '富有'果実において, 果肉硬度の低下が著しかった貯蔵10日から15日に急激に減少した。Na2CO3可溶性画分のウロン酸および糖量は, '富有'果実ではCDTA可溶性画分と同様に貯蔵10日から15日に急激に減少したが, '平核無'果実においてはその減少程度は小さかった。
    (3) GTC可溶性画分の糖量は, '平核無'果実および'富有'果実とも貯蔵期間中に大きな変化はなく, 差もなかった。
    以上より, 脱渋処理を行わない, エチレン生成の関与しない'平核無'果実の軟化は, 前報と同様に水溶性ペクチン画分のウロン酸量の増加と, 水不溶性ペクチン質のウロン酸量の減少が関係していると思われた。'富有'果実は, '平核無'果実に比べペクチン質量が多く, 各画分のウロン酸量および糖量が果肉硬度の低下と類似した傾向を示していた。'平核無'果実と'富有'果実の肉質の違いはペクチン質のウロン酸量の違いによるものであると推察された。
  • Yoshihiro Imahori; Mika Kota; Yoshinori Ueda; Megumi Ishimaru; Kazuo Cachin
    Postharvest Biology and Technology 25 2 159 - 167 2002年 [査読有り]
     
    Bell pepper fruit were stored under a continuous flow of 0 and 1% O2 (balance N2) or air for 7 days at 20°C to study the regulation of ethanolic fermentation. The concentrations of ethanol and acetaldehyde were very low during storage at 1% O2 and air. At 0% O2, ethanol and to a lesser extent acetaldehyde, rapidly accumulated in the tissue. Pyruvate decarboxylase (PDC) activity greatly increased in fruit exposed to 1% O2, while activity in fruit exposed to 0% was only slightly higher than that of the control. Alcohol dehydrogenase (ADH) activity greatly increased in fruit exposed to 1% but at 0% O2 was at the same level as the control. The activity of ADH was about 10 times that of PDC during storage. Changes in ADH isozymes correlated well with changes in ADH activity. Concentration of NADH did not change during storage in air, but in fruit in 0 and 1% O2 showed a significant increase. Concentrations of pyruvate were very low and did not change during storage at 1% O2 and air. At 0% O2, pyruvate rapidly accumulated in the tissue. The Km of ADH in bell pepper fruit was 0.74 mM for acetaldehyde, and 0.33 mM for NADH. The Km of PDC in bell pepper fruit was 0.92 mM for pyruvate. Possible regulation of ethanolic fermentation is briefly considered. © 2002 Elsevier Science B.V. All rights reserved.
  • Megumi Ishimaru; Shozo Kobayashi
    Plant Science 162 4 621 - 628 2002年 [査読有り]
     
    Six partial cDNAs for cell wall degradation-related enzymes, xyloglucan endo-transglycosylase (XET), polygalacturonase (PG), pectin methylesterase (PME), pectate lyase (PL), cellulase (Cel), and β-D-galactosidase (GAL), were isolated from a véraison -specific subtractive library made from Kyoho grape (Vitis labruscana) berries. During the development of Kyoho grape berries, the expression of these genes was analyzed. Among the genes analyzed, XET gene expression was closely related to berry softening slight XET gene expression was detected before véraison and was markedly increased at véraison (the stage of the onset of berry softening). In addition, the expression of the gene was berry specific. In the other genes, except for PL, however, no expression was detected during the berry development PL was detected only after the coloring stage began. These observations suggest that XET plays an important role in grape berry softening. To obtain further information about this gene, a full-length cDNA clone (VXET 1) encoding XET was isolated from a cDNA library of Kyoho grape berries and characterized. The VXET 1 was 1326 bp in length and contained a 5′-untranslated region of 67 bp, an open reading frame of 873 bp, and a 3′-untranslated region of 386 bp. The deduced amino acid sequence of the VXET 1 showed 73.5% identity with the corresponding XET (NXG 1) from nasturtium (Tropaeolum majus) that has been shown to have endo-glucanase activity. These findings suggest that the VXET 1 product cleaves a cellulose-xyloglucan network of cell wall and induces the softening of Kyoho grape berries at véraison. © 2002 Elsevier Science Ireland Ltd. All rights reserved.
  • Y. Imahori; I. Kishioka; K. Uemura; H. Yoshioka; Y. Ueda; M. Ishimaru; K. Chachin
    Journal of Horticultural Science and Biotechnology 77 6 677 - 682 2002年 [査読有り]
     
    Japanese pear 'Kosui' fruits were stored under a continuous flow of 0%, 1%, 3%, 5% and 10% O2 (balance N2) or air for 7 d at 20°C to study the effects of low O2 on their physiological responses and quality attributes. Low O2 treatments did not significantly influence changes in skin colour and soluble solids content. However, weak off-flavours were detected in the fruits stored at 0% O2 on day 3, and the intensity of these off-flavours increased as storage progressed. The concentrations of acetaldehyde in fruit increased throughout the storage period. The ethanol concentration was greatly increased in fruits stored at 0% O2. Moreover, ethanol concentrations were much higher than those of acetaldehyde and remained very low during storage in air, but their concentration were just slightly increased in fruits exposed to 1%, 3%, 5% and 10% O2. Pyruvate decarboxylase activity was greatly increased in fruits exposed to 1% and 3% O2, while its activity in fruits exposed to 5% and 10% O2 were only slightly higher than that of the control and at 0% O2 at the same level as the control. Alcohol dehydrogenase (ADH) activity greatly increased in fruit exposed to 0%, 1%, 3% and 5% O2, while at 10% O2, ADH was only slightly higher than the control. Changes in ADH isozymes correlated well with changes in ADH activity. The homogenate pH of fruits exposed to 1%, 3%, 5% and 10% O2 and air remained constant, while in fruit stored at 0% O2 their pH increased. The potential for using low O2 atmospheres to help in maintaining the quality of Japanese pear 'Kosui' is discussed.
  • 石丸 恵; 茶珎和雄; 和田安規; 上田悦範
    日本食品保蔵科学会誌 27 4 197 - 204 Japan Association of Food Preservation Scientists 2001年06月 [査読有り]
     
    カキ'平核無'果実は脱渋後の肉質が緻密で柔らかく最も人気のある品種の一つである。'平核無'果実の主な脱渋方法はアルコール脱渋とCO2脱渋であり, その脱渋方法の違いによって果実の軟化速度が異なる。そこでその違いをCO2, 排出量とエチレン生成の変化ならびに果実の軟化に密接に関係するペクチン質およびヘミセルロースの変化から検討した。
    (1) 脱渋処理果実の呼吸量およびエチレン生成量は処理直後増加し, その後減少する傾向を示した。
    (2) PAW可溶性画分のウロン酸量はいずれの区も増加したが, その程度は対照区2脱渋区<アルコール脱渋区で, 糖量はアルコール脱渋区とCO2脱渋区ともに増加し, 対照区では変化が少なかった。CDTA可溶性画分のウロン酸量および糖量とも両脱渋処理区で減少し, 対照区では変化が少なかった。Na2CO3可溶性画分のウロン酸量はいずれの区でも減少し, その程度は対照区2脱渋区くアルコール脱渋区であった。
    (3) GTC可溶性画分の糖量は対照区でほとんど変化がなく, 脱渋処理区では処理後3日で半減した。KOH可溶性画分の糖量はGTC可溶性画分の糖量とほぼ同様の傾向を示した。
    以上より, カキ'平核無'果実の軟化は水溶性ペクチン画分のウロン酸量の増加と水不溶性ペクチン画分のウロン酸量の減少およびヘミセルロースの減少が関係していると思われた。アルコール脱渋とCO2脱渋に伴う軟化速度の違いは, 水溶性ペクチン画分のウロン酸量の増加と水不溶性ペクチン画分のウロン酸量の減少程度の違いであると推察される。
  • S. Kobayashi; M. Ishimaru; C. K. Ding; H. Yakushiji; N. Goto
    Plant Science 160 3 543 - 550 2001年02月 [査読有り]
     
    The expression of the UDP-glucose:flavonoid 3-O-glucosyltransferase (UFGT) gene has been shown to be critical for anthocyanin biosynthesis in the grape berry. Using white cultivars and bud sports with red skin, we examined the expression of seven anthocyanin biosynthetic genes including the UFGT gene and compared the coding/promoter sequences of the UFGT gene. Northern blot analysis showed that the seven anthocyanin biosynthetic genes were expressed coordinately at higher levels in the red-skin sports than in the white-skin progenitors of the sports. It was especially notable that UFGT gene expression was detected only in the red-skin sports and Kyoho. However, there were no differences in either coding or promoter sequences between Italia (Vitis vinifera) and its red-skin sport Ruby Okuyama, or between Muscat of Alexandria (V. vinifera) and the red-skin sport Flame Muscat. From these findings, the phenotypic change from white to red in the sports is thought to be the result of a mutation in a regulatory gene controlling the expression of UFGT. © 2001 Elsevier Science Ireland Ltd.
  • 石丸 恵; 森岡 啓; 山本貴司; 上田悦範; 茶珎和雄
    園芸学会雑誌 68 4 890 - 896 園藝學會 1999年12月 [査読有り]
     
    ハウスカキ'刀根早生'果実を用いて, 100%CO_2脱渋処理後にCO_2濃度を段階的に低下させる漸次低下処理がACC含量およびACC合成酵素とACC酸化酵素活性に及ぼす影響について調査した.1. ACC合成酵素活性は, カテキンの添加により著しく抑制されたが, BSAをACC合成酵素の抽出緩衝液に加えることによって, ACC合成酵素の活性を顕著に保持した.2. 未熟果実の無処理果実およびCTSD処理果実のACC含量は, 貯蔵中に急激に増加したが, CO_2濃度漸次低下処理果実では貯蔵期間中常に低いレベルであった.成熟果実においても, CO_2濃度漸次低下処理によってACC含量の蓄積が抑えられた.3. ACC合成酵素活性は, 未熟果実および成熟果実のCO_2濃度漸次低下処理果実で, 無処理およびCTSD処理果実より低く, 未熟果実でその活性はより強く抑えられた.4. ACC酸化酵素活性は未熟果実および成熟果実においても, CO_2濃度漸次低下処理によって抑制されたが, その抑制程度はACC合成酵素活性に対する抑制効果より小さかった.以上のことから, CO_2濃度漸次低下処理はACC合成酵素活性を強く抑制し, 結果的にエチレン生成を抑えるものと考えられた.
  • 石丸 恵; 山本貴司; 茶珎和雄
    園芸学会雑誌 67 5 812 - 814 園藝學會 1998年10月 [査読有り]
     
    ハウスカキ'刀根早生'果実はCO_2脱渋後極めて短期間で軟化するため, その防止法として100% CO_2脱渋後に, CO_2濃度を段階的に低下させる方法を検討した.その結果, 総CO_2脱渋処理時間を24時間として, 100% CO_2処理後, CO_2濃度を漸次低下させたCO_2濃度低下処理果実では, 無処理果実および対照処理果実より呼吸量, エチレン生成量とも抑えられ, 果実硬度も対照果実で6∿10日で軟化するのに対して, CO_2濃度を漸次低下した果実では約2週間程度保持されることが認められた.
  • Effects of on-tree removal of astringency by ethanol treatment on β-D-galacosidase gene expression of Japanese persimmon Tonewase fruit.
    Ishimaru M; Kobayashi S; Imahori Y; Ueda Y
    Applied Biological Science 4 77 - 83 1998年10月 [査読有り]
  • 石丸 恵; 今堀義洋; 辰巳保夫; 茶珎和雄
    日本食品保蔵科学会誌 24 4 243 - 247 Japan Association of Food Preservation Scientists 1998年06月 [査読有り]
     
    カット野菜の微生物制御技術として用いられる次亜塩素酸ナトリウム溶液浸漬処理は, カットレタスおよびカットキャベツ中のァスコルビン酸含量を減少させ, 洞時に酸化型アスコルビン酸占有率を高めることや, 次亜塩素酸ナトリウム溶液処理後の水洗工程でアスコルビン酸の流失も伴うことが示された。

書籍

  • 山内, 直樹; 今堀, 義洋 (担当:分担執筆範囲:)文永堂出版 2021年04月 ISBN: 9784830041426 xvi, 293p
  • 食品加工・保蔵学
    石丸 恵 (担当:分担執筆範囲:)2017年07月
  • 地球変動研究の最前線を訪ねる
    小川利紘; 及川武久; 陽 捷行; 石丸 恵 (担当:共著範囲:)清水弘文堂 2010年02月

講演・口頭発表等

  • モモ果実由来エクスパンシンの糖加水分解活性について  [通常講演]
    松山佳織; 近藤辰哉; 阪本龍司; 砂川直輝; 五十嵐圭日子; 石丸 恵
    第11回細胞壁研究者ネットワーク定例会 2017年10月 口頭発表（一般）
  • モモ果実由来エクスパンシンの糖加水分解活性  [通常講演]
    松山佳織; 近藤辰哉; 阪本龍司; 砂川直輝; 五十嵐圭日子; 石丸 恵
    日本応用糖質科学会平成29年度大会 2017年09月 口頭発表（一般）
  • 新規植物親和性材料およびその利用について（第一報）  [通常講演]
    石丸 恵; 古薗 勉; 神崎真哉; 伴 琢也
    園芸学会平成29年度秋季大会 2017年09月 口頭発表（一般）
  • 青果物の収穫後の高温環境による生理化学変化とその利用  [招待講演]
    石丸 恵
    日本食品保蔵科学会第66回大会 2017年06月 シンポジウム・ワークショップパネル（指名）
  • ブドウ黒とう病に対する抵抗性機構の解明（第三報）  [通常講演]
    宮本綾子; 河野 淳; 今堀義洋; 石丸 恵
    園芸学会平成29年度春季大会 2017年03月 口頭発表（一般）
  • モモ果実の軟化に関与するPpEXP1の糖加水分解活性の有無について  [通常講演]
    松山佳織; 近藤辰哉; 阪本龍司; 石丸 恵
    園芸学会平成29年度春季大会 2017年03月 口頭発表（一般）
  • トマトβ-ガラクトシダーゼ４のアミノ酸変異（V548W)導入による酵素特性および基質特異性の変化  [通常講演]
    松山佳織; 近藤辰哉; 阪本龍司; 石丸 恵
    第10回細胞壁ネットワーク定例会 2016年10月 口頭発表（一般）
  • モモ果実の軟化に関与するPpEXP1の機能解析に向けた基礎的研究  [通常講演]
    松山佳織; 小野裕美; 今井友也; 石丸 恵
    園芸学会平成28年度秋季大会 2016年09月 口頭発表（一般）
  • ブドウ黒とう病に対する抵抗性機構の解明（第二報）  [通常講演]
    宮本綾子; 河野 淳; 佐藤明彦; 今堀義洋; 石丸 恵
    園芸学会平成28年度春季大会 2016年03月 口頭発表（一般）
  • トマトβ-ガラクトシダーゼ４のアミノ酸変異（V548W)導入による酵素特性および基質特異性の変化  [通常講演]
    松山佳織; 近藤辰哉; 阪本龍司; 石丸 恵
    園芸学会平成28年度春季大会 2016年03月 口頭発表（一般）
  • トマト果実の軟化に関与するβ-ガラクトシダーゼ１および５の機能解析  [通常講演]
    近藤辰哉; 松山佳織; 阪本龍司; 石丸 恵
    園芸学会平成28年度春季大会 2016年03月 口頭発表（一般）
  • ブドウ黒とう病に対する抵抗性機構の解明  [通常講演]
    宮本綾子; 河野 淳; 佐藤明彦; 今堀義洋; 石丸 恵
    園芸学会平成27年度秋季大会 2015年09月 口頭発表（一般）
  • トマトβ-ガラクトシダーゼ４のアミノ酸変異導入による酵素特性の変化  [通常講演]
    近藤辰哉; 米山将史; 狩野卓也; 阪本龍司; 石丸 恵
    園芸学会平成27年度春季大会 2015年03月 口頭発表（一般）
  • ブタE型肝炎ウイルス遺伝子（ORF2）を導入した形質転換体の作出  [通常講演]
    近藤辰哉; 安江 博; 松原悠子; 中川隆生; 石丸 恵
    園芸学会平成26年度秋季大会 2014年09月 口頭発表（一般）
  • トマトβ-ガラクトシダーゼ４の結晶構造解析  [通常講演]
    石丸 恵; 枝 真広; 多田俊治
    園芸学会平成25年度秋季大会 2013年09月 口頭発表（一般）
  • 殺菌処理後にactiveMAP貯蔵されたカットレタスおよびカットホウレンソウの微生物的品質と貯蔵性  [通常講演]
    泉 秀実; ヴァラコン リーラヴォラヴォン; 三木秀基; 田口佳秀; 石丸 恵
    日本食品保蔵科学会第60回大会 2011年06月 東京農業大学生物産業学部（網走市） 日本食品保蔵科学会第60回大会
     
    カットレタスとホウレンソウに適した抗菌剤で殺菌処理後に，高二酸化炭素を充填したactiveMAP 貯蔵を行い，貯蔵中の微生物的品質と貯蔵性を調査した。
  • バナナ果実（cv. Senorita) におけるアミノ酸からアルコール残酸基の供給経路の解明  [通常講演]
    ウェンダコーン S.K; 石丸 恵; 上田悦範
    日本食品保蔵科学会 2011年06月 北海道網走市 日本食品保蔵科学会
  • トマトβ-ガラクトシダーゼ (TBG) ４の結晶化  [通常講演]
    石丸 恵; 枝 真広; 多田俊治
    日本食品保蔵科学会 2011年06月 北海道網走市 日本食品保蔵科学会
  • 殺菌処理後にactiveMAP貯蔵されたカットニンジンおよびダイコンの微生物的品質と貯蔵性  [通常講演]
    泉 秀実; 三木秀基; ヴァラコン リーラヴォラヴォン; 村上ゆかり; 石丸 恵
    日本食品保蔵科学会第60回大会 2011年06月 東京農業大学生物産業学部（網走市） 日本食品保蔵科学会第60回大会
     
    カットニンジンとダイコンに適した抗菌剤の組合わせで殺菌処理後に，高二酸化炭素を充填するactiveMAP貯蔵を行い，10℃貯蔵中の微生物的品質と貯蔵性を評価した。
  • 酵素剥皮およびナイフ剥皮されたカットカキの微生物叢と品質  [通常講演]
    泉 秀実; 村上ゆかり; 足立卓弥; 石丸 恵; 尾崎嘉彦
    日本食品保蔵科学会第60回大会 2011年06月 東京農業大学生物産業学部（網走市） 日本食品保蔵科学会第60回大会
     
    酵素剥皮行程中のカットカキの微生物叢を把握し，ナイフ剥皮されたカットカキと微生物汚染度および品質を比較した。
  • 食の安全・安心について考える～リスク評価・管理からリスクコミュニケーションまで～  [通常講演]
    泉 秀実; 石井 營次; 石丸 恵
    第8回食の安全シンポジウム（和歌山県・近畿大学生物理工学部食品安全工学科） 2011年01月 和歌山市 第8回食の安全シンポジウム（和歌山県・近畿大学生物理工学部食品安全工学科）
     
    パネルディスカッション「食の安全・安心について考える～リスク評価・管理からリスクコミュニケーションまで～」において、コーディネーターを務めた。

MISC

産業財産権

受賞

  • 日本食品保蔵科学会奨励賞（2006）

共同研究・競争的資金等の研究課題

  • 日本学術振興会：科学研究費助成事業 基盤研究(C)
    研究期間 : 2019年04月 -2022年03月 
    代表者 : 石丸 恵
     
    モモ果実由来のPpEXP1は，モモ果実の軟化に深く関与していることが明らかにされているが，その詳細は不明であった．そこで，本課題によってPpEXP1はセルロースに対して加水分解活性を有することを明らかにした．さらに，セロオリゴ糖を基質にすると，2～4糖については加水分解活性を示さず，5糖を2糖と3糖に6糖を2糖と4糖にそれぞれ加水分解することを明らかにした． また，果実軟化を高分子構造体の構造変化として細胞壁の構造変化を明らかにする目的で，X線小角散乱法を用いた．その結果，細胞壁の構造変化を観察することができ，さらには，PpEXP1の関与も明らかにすることができた．
  • 果実軟化に関与するエクスパンシンの機能解明と分子構造研究
    国立遺伝学研究所：先進ゲノム支援
    研究期間 : 2020年04月 -2021年03月 
    代表者 : 石丸 恵
  • 長期貯蔵を目的としたモモ果肉形質の遺伝子多型解析
    東京農業大学生物資源ゲノム解析センター：共同利用・共同研究課題
    研究期間 : 2020年04月 -2020年10月 
    代表者 : 石丸 恵
  • 青果物の長距離輸送におけるストレス処理を利用した品質保持技術の検討並びに評価
    文部科学省：科学研究費補助金（基盤研究（B)）
    研究期間 : 2014年04月 -2016年03月 
    代表者 : 山内直樹
  • 文部科学省：科学研究費補助金(基盤研究(C))
    研究期間 : 2011年 -2013年 
    代表者 : 石丸 恵
     
    本研究課題は，トマト果実をモデルとして果実の発育・成熟過程における細胞壁分解酵素の一つであり，トマト果実の軟化に重要な役割を果たしていると考えられるβ-ガラクトシダーゼについて，酵素特性や基質認識機構を明らかにすることを目的とした．トマトβ-ガラクトシダーゼ（TBG)4は果実軟化に重要な役割を果たしているため，酵母による発現系を構築し，X線結晶構造解析を行った．その結果，植物では初めてβ-ガラクトシダーゼの構造を明らかにすることができた．また，TBG1の酵素特性も明らかにし，TBG4とは異なる基質特異性を持つことを明らかにした．
  • 文部科学省：科学研究費補助金(基盤研究(B))
    研究期間 : 2010年 -2012年 
    代表者 : 山内 直樹; 執行 正義; 今堀 義洋; 石丸 恵; 寺井 弘文; 鈴木 康生
     
    本研究はストレス処理(高温,エタノール,UV-B,過酸化水素)による園芸作物の貯蔵中における品質保持効果について,生理・生化学・分子生物学的側面から追究し,各作物に最適なストレス処理についての検討を行った.得られた結果から,ストレス処理による活性酸素生成と消去システム活性化,エチレン生成制御および内容成分保持が貯蔵中の品質保持効果につながっていることを解明するとともに,ストレス処理が新たな貯蔵技術の発展に寄与する可能性を持つものと推察した.
  • 文部科学省：科学研究費補助金(基盤研究(C))
    研究期間 : 2007年 -2008年 
    代表者 : 石丸 恵
     
    本研究は, ブドウ果実の成熟過程に起こる急速な軟化現象を細胞壁構造と細胞壁分解酵素遺伝子の発現から明らかにしようと試みたものである.その結果, ブドウ果実の内部の組織の違いにより軟化過程の速度もしくは構造変化が異なること, ベレゾーン期の急速な軟化は細胞壁のヘミセルロース, 特にキシログルカンの低分子化によって起こるであることが明らかとなった.今後組換えタンパクなどを用いて詳細に調査する必要がある.
  • メロン果実の香気生成酵素遺伝子の単離と解析
  • ブドウ果実の成熟関連遺伝子の単離と解析
  • Cloning and analysis of acetyl Co A transferase gene from melon fruit
  • Cloning and analysis of ripening-related genes from grape berries

委員歴

  • 2019年 - 現在   園芸学会   Hort. J.上級編集委員
  • 2016年10月 - 現在   園芸学会   Hort J.編集委員
  • 2015年06月 - 現在   日本食品保蔵科学会   企画・広報委員
  • 2015年04月 - 2018年03月   西宮市   西宮市食育食の安全安心推進会議委員
  • 2013年04月 - 2016年03月   園芸学会   園芸学研究編集委員

担当経験のある科目

  • 食品生物学実験近畿大学
  • 食品安全工学実験近畿大学
  • 食品加工実習東京農工大学，大阪大谷大学，羽衣国際大学
  • 食品加工学近畿大学，東京農工大学，大阪大谷大学
  • 食品流通論近畿大学
  • 遺伝資源学近畿大学
  • 植物生理学近畿大学

その他

  • 2015年04月 - 2015年04月  バイオマテリアルを応用した新規接ぎ木技術の開発とメカニズムの解明 
    近畿大学学内研究助成金 21 世紀研究開発奨励金（共同研究助成金） KD04 研究内容：当該研究課題は，ハイドロキシアパタイト（HAp）ナノ粒子複合体を用いた種々の医療用生体材料による果樹の接ぎ木活着率の向上および活着期間の短縮を目的とした効率的接ぎ木技術の開発とそのメカニズムの解明を目指す．

その他のリンク

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