Ibaraki University's
Ibaraki University

顔写真
Vice President

OHTA Hiroyuki

  • Birth:1954

Career

  1. Tohoku University Institute for Agricultural Research Postdoctoral fellow, Japan Promotion of Science 1982/04/01-1984/03/31
  2. Okayama University Dental School Assistant Professor 1984/04/01-1992/05/31
  3. Okayama University Dental School Associtae Professor 1992/06/01-1997/07/31
  4. Ibaraki University College of Agriculture Associtae Professor 1997/08/01-2002/05/31
  5. Ibaraki University College of Agriculture Professor 2002/06/01-Present
  6. Ibaraki University Vice President 2014/09/01-2016/03/31
  7. Ibaraki University Director, Vice President (Education) 2016/04/01-Present

Academic background

  1. Tohoku University Faculty of Agriculture 農芸化学 1977 Graduated
  2. Tohoku University Graduate School, Division of Agriculture 農芸化学 Doctor course 1982 Completed

Academic degrees

  1. Doctor of Agricultural Science Tohoku University
  2. Master of Agricultural Science Tohoku University

Current state of research and teaching activities

①アルキルフェノール系化合物の環境動態と関与する微生物の生態に関する研究:農薬の副資材として使われるアルキルポリエトキシレートの土壌での動態と分解に関わる微生物の解析を行い、分解経路と分解遺伝子の解明をめざしている。
②新生火山噴出物における微生物生態系の解析:火山噴出物被害地帯における生態系再生に向けて、被害地土壌の微生物生態系を解析している。これまでに、フィリピン・ピナツボ火山泥流被害地帯、三宅島火山灰堆積地帯での調査、研究を行ってきた。
③森林土壌中の菌核様粒子に生息する微生物の分類学的および生理・生化学的研究:菌核様粒子は、酸性条件では生物に有害に働くアルミニウムを多く含む点で特徴的であり、その粒子から分離された微生物の機能を解析している。
④病原細菌の環境応答に関する研究:白血球毒素を産生する病原性細菌の毒素産生と環境因子との関係を解析している。
⑤畑地からの亜酸化窒素発生に関わる微生物の研究:近年、糸状菌の亜酸化窒素産生性の脱窒作用が生化学的に明らかにされている。本研究では、畑地の脱窒活性を見積り、その中での糸状菌の役割を明らかにしようとするものである。

Research Areas

  1. Environmental Dynamic Analysis
  2. Environmental Influence Valuation/Environment Policy
  3. Plant Nutrient Science/Soil Studies

Research keywords

  1. Microbial Ecology, Environmental Chemistry and Toxicology, Microbial Physiology, Bacterial Taxonomy

Subject of research

  1. Taxonomy and genetic analysis of soil oligotrophic bacteria 1998-Present
  2. Microbial community analysis of young volcanic ash 1998-Present
  3. Molecular Ecology of Nonylphenol-degrading bacteria 2000-Present
  4. Microbial ecology of sclerotium grains in foreast soils 2001-Present
  5. Analysis of microbial ecosystem structure and development in the space environment and Martian analogs 2004-Present
  6. Ecology and physiology of nitrous oxide-producing microbes in upland soils 畑地に分布する糸状菌の亜酸化窒素発生活性とその発生メカニズムを解析している 2005/04-Present
  7. Global change adaptation science 2006-Present
  8. スイートソルガムを用いたバイオブタノール生産に関する研究

Bibliography

  1. 農学が世界を救う! 食料・生命・環境をめぐる科学の挑戦 生源寺眞一 、太田寛行、安田弘法 岩波ジュニア新書 2017/10/20 9784005008612
  2. 難培養微生物研究の最前線III 太田寛行、佐藤嘉則、西澤智康 シーエムシー出版 2015/08/07 本章の前半では,筆者らが行ってきた「内生細菌の検出方法」を紹介し,次に,これまでに報告されてきた「内生細菌の系統」を概観する。後半では,2つの糸状菌-内生細菌の関係に焦点をあて,それらの研究の進展を概説し今後の展望について述べる。
  3. 微生物の地球化学 太田寛行、難波謙二、諏訪裕一、片山葉子 東海大学出版部 2015/06/30 978-4-486-02070-7
  4. 農学入門-食料・生命・環境科学の魅力- 太田寛行・成澤才彦 養賢堂 2013/09/20 978-4-8425-0519-0
  5. Establishing a Resource-Circulating Society in Asia: Challenges and Opportunities Niita, Y., H. Ohta, and T. Kato United Nations University Press 2011 978-92-808-1184-1

Papers

  1. Research paper (scientific journal) Joint Mortierella sugadairana, a new homothallic species related to the firstly described heterothallic species in the genus Yusuke Takashima, Yousuke Degawa, Hiroyuki Ohta, Kazuhiko Narisawa Mycoscience Elsevier B.V. 59/ 3, 200-205 2018/05 10.1016/j.myc.2017.10.004 A new species, Mortierella sugadairana, is described for a fungus forming homothallic zygospores with a club-shaped macrosuspensor and a microsuspensor originating from the macrosuspensor. The species was isolated from cool regions in Japan and morphologically and phylogenetically close to a heterothallic species M. parvispora, which is the first species reported as a heterothallic species in the genus. Mycelial growth of the species was limited at 30 °C, whereas two isolates of M. parvispora can grow. This may indicate that the species and M. parvispora adapted to different climates from a common ancestor involving differentiation of the manner of reproduction.
  2. Research paper (scientific journal) Joint Comparative genomic insights into endofungal lifestyles of two bacterial endosymbionts, Mycoavidus cysteinexigens and Burkholderia rhizoxinica Dilruba Sharmin, Yong Guo, Tomoyasu Nishizawa, Shoko Ohshima, Yoshinori Sato, Yusuke Takashima, Kazuhiko Narisawa, Hiroyuki Ohta Microbes and Environments 33/ 1, 66-76 2018/03/29 10.1264/jsme2.ME17138 Endohyphal bacteria (EHB), dwelling within fungal hyphae, markedly affect the growth and metabolic potential of their hosts. To date, two EHB belonging to the family Burkholderiaceae have been isolated and characterized as new taxa, Burkholderia rhizoxinica (HKI 454T) and Mycoavidus cysteinexigens (B1-EBT), in Japan. Metagenome sequencing was recently reported for Mortierella elongata AG77 together with its endosymbiont M. cysteinexigens (Mc-AG77) from a soil/litter sample in the USA. In the present study, we elucidated the complete genome sequence of B1-EBT and compared it with those of Mc-AG77 and HKI 454T.
  3. Research paper (scientific journal) Joint Effect of Rhizobium species living with a dark septate endophytic fungus Veronaeopsis simplex on host’s organic substrate utilization Yong Guo, Yuuto Matsuoka, Tomoyasu Nishizawa, Hiroyuki Ohta, Kazuhiko Narisawa Microbes and Environments 33/ 1, 102-106 2018/03/29 10.1264/jsme2.ME17144 Bacteria harbored in/on the hyphae of the dark septate endophyte, Veronaeopsis simplex Y34, were identified as a single Rhizobium species by molecular analyses of bacterial 16S rRNA genes, and were successfully isolated from the endophyte.
  4. Research paper (scientific journal) Joint Draft genome sequences of Aggregatibacter actinomycetemcomitans strains 310a and 310b Anthony C. May, Hiroyuki Ohta, Hiroshi Maeda, Susumu Kokeguchi, Carla Cugini Genome Announcements American Society for Microbiology 5/ 47, e01282-17 2017/11/22 10.1128/genomeA.01282-17 We report the draft genomic sequences of Aggregatibacter actinomycetemcomitans strains 310a (310-TR) and 310b (310-OS). Strain 310a is a clinical isolate with a rough phenotype. Strain 310b is a lab adapted isolate derived from the passage of 310a; it displays a smooth phenotype.
  5. Research paper (scientific journal) Joint 岐阜県御嶽山の森林土壌から採取した菌核の培養法および非培養法による菌類群集解析 野々山(佐々木)弥・坂上伸生・成澤才彦・太田寛行・渡邊眞紀子 土と微生物(Soil Microorganisms) 日本土壌微生物学会 70/ 2, 56-59 2016  岐阜県御嶽山の土壌から採取した菌核において,菌核形成菌を推定するためにクローンライブラリー法および菌類の分離をおこなった。クローンライブラリー法により,菌核形成菌として報告されているCenococcum geophilum が認められた。分離された糸状菌は,その大部分が子囊菌類であった。培養法ではC. geophilumが認められなかったものの, DSE に類別されると考えられる未同定菌3 株が,人工培地上で菌核を形成した。本研究で供試した菌核は, C. geophilum だけでなく,他の菌種により形成された可能性もあると考えられた。

Research presentations

  1. Poster presentation Molecular Analysis of Microbial Community in Water Stable Aggregation of Upland Field Soils Managed by No-tillage Practices for Seven Years XVII International Colloquium on Soil Zoology 2016/08/24 Agricultural soil management practices by no-tillage and cover-cropping improve the formation of soil aggregate structures and provide storage space of nutrients that can be utilized by soil microbes. The objective of the present study was to assess the effects of tillage/no-tillage management for seven years on soil microbial diversity and its community dynamics in upland fields. In addition, we examined that the aggregate formation correlates with soil microbes in no-tilled soils.
  2. Poster presentation Microbial community structure analysis of water-stable soil aggregates in no-till cropping systems XVII International Colloquium on Soil Zoology 2016/08/24 There are increasing concerns for no-till cropping systems because they can lead to soil carbon sequestration to mitigate climate change. The potential for carbon sequestration in no-tilled soils is related to the content of water-stable aggregates (WSAs) which can constitute stable environments for microbes and organic matter. However, from the microbiological aspect, such WSAs are not yet fully characterized. This study aimed to analyze microbial communities of WSAs in relation to crop field managements. Our study sites were established in no-tilled and tilled soybean plots of the Andosol field maintained since 2003.
  3. Oral presentation(general) 不耕起栽培畑地土壌における耐水性団粒内の微生物群集構造解析 日本土壌微生物学会2016年度大会 2016/06/12 耕起による土壌の攪乱や大型機械の導入は,不耕起の場合と比べると土壌の物理性等に大きな違いが生じていると考えられる.特に,土壌団粒の発達への影響は大きいと推察される.先行研究では,耕起/不耕起や冬期カバークロップ栽培の有無等の農地土壌管理の違いが土壌微生物群集構造に与える影響を評価してきた.本研究では,耕起および不耕起栽培畑地土壌において,耐水性団粒のサイズ組成及び団粒スケールでの微生物群集構造の違いを明らかにすることを目的とした.
  4. Poster presentation Genome analysis of a DSE-commensal bacterium Rhizobium sp. Y9 associated with Veronaeopsis simplex Y34 日本土壌微生物学会2016年度大会 2016/06/11 A dark septate endophytic fungus, Veronaeopsis simplex Y34, was evaluated for many benefits to its host plant, such as suppression of soil born diseases, promotion of growth, and enhancement of resistance to environmental stresses. Interestingly, previous studies have indicated the presence of commensal bacteria living outside and inside mycelium of V. simplex Y34, and these bacteria probably affected the host-beneficial performance. One isolate of the commensal bacterium, Rhizobium sp. Y9 was successfully isolated from the community inhabiting the mycelium of the fungus. To unravel the role commensal bacteria in such triadic symbiosis, this study sequenced the whole genome of Rhizobium sp. Y9 and compared the genomic information with those of close related bacterium species.
  5. Poster presentation Mortierella属糸状菌に内生する細菌の多様性解析 日本土壌微生物学会2016年度大会 2016/06/11 微生物間で細胞内共生の関係があることが提起され、糸状菌ー内生細菌の関係では、アーバスキュラー菌根菌Gigaspora margaritaとその内生細菌Candidatus Glomeribacter gigasporum、イネ苗立枯病菌Rhizopus microsporusとリゾキシン産生内生細菌Burkholderia rhizoxinicaで詳しく研究されてきた。本研究では、我々が先に報告した新たな糸状菌ー内生細菌ペアーであるMoriterella elongataーMycoavidus cysteinexigens以外のMoriterella属糸状菌における内生細菌の分布と多様性を解析した。

Prizes

  1. Udayana Award 2016/09/29 Regarding to Ohta's effort and great contribution in promoting and strengthening the cooperation between the University of Udayana and Ibaraki University, Ohta has been chosen to receive the University of Udayana Award of 2016.
  2. 第59回日本土壌肥料学会賞 土壌細菌の分類および群集解析に関する研究 2014/09/10
  3. 特別研究員等審査会専門委員(書面担当) 表彰 2013/07/31
  4. JSME Prize 2010 for the best publication Nitrogenase activity (Acetylene Reduction) of an Iron-Oxidizing Leptospirillum Strain Cultured as a Pioneer Microbe from a Recent Volcanic Deposit on Miyake-jima, Japan 2010/11/25 The authors were awarded in recognition of excellence in form, and content of the authors' paper published in Microbes and Environments, volume 24, 2009.
  5. 両備(]J3727[)園記念財団研究助成 1993

Alloted class

  1. Advanced Environmental Toxicology and Chemistry
  2. Analytical Chemistry
  3. Fundamentals of Soil Science
  4. Environmental chemistry and toxicology
  5. Overview of agricultural science toward regional sustainability

Memberships of academic societies

  1. 日本土壌微生物学会
  2. International Society of Microbial Ecology
  3. American Society for Microbiology
  4. The Society for General Microbiology
  5. 日本農芸化学会

Committee Career

  1. Japanese Society for Soil Microbiology 評議員 2010/01/01-2012/12/31
  2. International Society for Environmental Biogeochemistry International Committee 2009-2013
  3. 日本土壌微生物学会 評議員 2007/06-2013/05
  4. Japanese Society for Soil Microbiology 学会誌編集委員 2005/01-2008/12
  5. Japanese Society for Soil Microbiology 評議員 2005/01-2008/12