Laboratory of Marine Molecular Ecology (MME)

Yumiko Obayashi, Senior Assistant Professor  

 
  •  
2002 Ph. D., Earth Science, Nagoya University, Japan.
“Dynamics of phytoplankton community structure in the northern North Pacific”
2003-2006 Postdoctoral fellow, CMES, Ehime University
2007 Postdoctoral fellow, International Christian University
2008 Research Scientist, CMES, Ehime University
2009-2014 Research Associate, Yokohama National University
2014-2015 Research Scientist, University of Tsukuba
2015- Assistant Professor, Ehime University

Research Fields:

 Biogeochemistry,
 Oceanography,
 Aquatic microbial ecology,
 Astrobiology,

E-mail: obayashi.yumiko.nn * ehime-u.ac.jp
(“ * ” should be replaced to @)

Research Publications

  • Obayashi, Y., Kadoya, A., Kataoka, N., Kanda, K., Bak, S-M., Iwata, H. and Suzuki, S. (2020) Tetracycline resistance gene profiles in red seabream (Pagrus major) intestine and rearing water after oxytetracycline administration. Front. Microbiol., 11, 1764, doi: 10.3389/fmicb.2020.01764
  • Obayashi, Y. and Suzuki, S. (2019) High growth potential of transiently 0.2-µm-filterable bacteria with extracellular protease activity in coastal seawater. Plankton and Benthos Research, 14, 276-286.
  • Obayashi, Y., Bong, C.W. and Suzuki, S. (2017) Methodological considerations and comparisons of measurement results for extracellular proteolytic enzyme activities in seawater. Front. Microbiol.,8, article 1952, doi:10.3389/fmicb.2017.01952.
  • Bien, T.L.T.,Thao, N.V., Kitamura, S-I., Obayashi, Y. and Suzuki, S. (2017) Release and constancy of an antibiotic resistance gene in seawater under grazing stress by ciliates and heterotrophic nano flagellates. Microbes Environ., 32,174-179. doi:10.1264/jsme2.ME17042
  • Ngo Vy Thao, Akino Nozawa, Yumiko Obayashi, Shin-Ichi Kitamura, Taichi Yokokawa, Satoru Suzuki (2015): Extracellular proteases are released by ciliates in defined seawater microcosms.  Marine Environmental Research, 109, 95-102.           doi:10.1016/j.marenvres.2015.06.011
  • Ngo Vy Thao, Yumiko Obayashi, Taichi Yokokawa, Satoru Suzuki (2014): Coexisting protist-bacterial community accelerates protein transformation in microcosm experiments.  Frontiers in Marine Science, 1:69.  doi:10.3389/fmars.2014.00069
  • Kensei Kobayashi, Hajime Mita, Hikaru Yabuta, Kazumichi Nakagawa, Yukinori Kawamoto, Takeo Kaneko, Yumiko Obayashi, Kazuhiro Kanda, Satoshi Yoshida, Issay Narumi, Eiichi Imai, Hirofumi Hashimoto, Shin-ichi Yokobori, Akihiko Yamagishi, Tanpopo WG (2014): Space exposure of amino acids and their precursors in the Tanpopo Mission using the International Space Station.  Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology Japan, 12 (ists29), Pp_1-6.  doi: 10.2322/tastj.12.Pp_1
  • Kuhan Chandru, Yumiko Obayashi, Takeo Kaneko, Kensei Kobayashi (2013): Formation of amino acid condensates partly having peptide bonds in a simulated submarine hydrothermal environment.  Viva Origino, 41(3), 24-28.
  • Jun Kawai, Seema Jagota, Takeo Kaneko, Yumiko Obayashi, Yoshitaka Yoshimura, Bishun N. Khare, David W. Deamer, Christopher P. McKay, Kensei Kobayashi (2013): Self-assembly of tholins in environments simulating Titan liquidospheres: Implications for formation of primitive coacervates on Titan.  International Journal of Astrobiology, 12(4), 282-291.  doi: 10.1017/S1473550413000116
  • Jun Kawai, Seema Jagota, Takeo Kaneko, Yumiko Obayashi, Bishun N. Khare, Christopher P. McKay, Kensei Kobayashi (2013): Titan tholins as amino acid precursors and their solubility in possible Titan liquidospheres  Chemistry Letters, 42(6), 633-635.  doi: 10.1246/cl.130101
  • Kuhan Chandru, Eiichi Imai, Takeo Kaneko, Yumiko Obayashi, Kensei Kobayashi (2013): Survivability and abiotic reactions of selected amino acids in different hydrothermal system simulators.  Origins of Life and Evolution of Biospheres, 43(2), 99-108.  doi: 10.1007/s11084-013-9330-9
  • Palash K. Sarker, Jun-ichi Takahashi, Yumiko Obayashi, Takeo Kaneko, Kensei Kobayashi (2013): Photo-alteration of hydantoins against UV light and its relevance to origin of life.  Advances in Space Research, 51, 2235-2240.  doi: 10.1016/j.asr.2013.01.029
  • Chui Wei Bong, Yumiko Obayashi, Satoru Suzuki (2013): Succession of protease activity in seawater and bacterial isolates during starvation in a mesocosm experiment.  Aquatic Microbial Ecology, 69, 33-46.  doi: 10.3354/ame01618
  • Palash K. Sarker, Jun-ichi Takahashi, Yumiko Obayashi, Takeo Kaneko, Kensei Kobayashi (2012): Photo-alteration of isovaline and its precursor 5-ethyl-5-methylhydantoin exposed to UV and g-ray radiation.  Viva Origino, 40(2), 4-8.
  • Hideharu Kuwahara, Midori Eto, Yukinori Kawamoto, Hironari Kurihara, Takeo Kaneko, Yumiko Obayashi, and Kensei Kobayashi (2012): The use of ascorbate as an oxidation inhibitor in prebiotic amino acid synthesis: A cautionary note.  Origins of Life and Evolution of Biospheres, 42(6), 533-541.  doi: 10.1007/s11084-012-9296-z.
  • Hironari Kurihara, Yoshinori Takano, Takeo Kaneko, Yumiko Obayashi, Kensei Kobayashi (2012): Stability of amino acids and related compounds in simulated submarine hydrothermal systems.  Bulletin of the Chemical Society of Japan, 85(5), 624-630.   doi: 10.1246/bcsj.20110349
  • Hironari Kurihara, Hikaru Yabuta, Takeo Kaneko, Yumiko Obayashi, Yoshinori Takano, Kensei Kobayashi (2012): Formation of organic aggregates by heating the products of simulated primitive atmosphere experiments.  Chemistry Letters, 41(4), 441-443.  doi:10.1246/cl.2012.441  IF: 1.300
  • Kensei Kobayashi, Palash K. Sarker, Keisuke Ono, Yukinori Kawamoto, Yumiko Obayashi, Takeo Kaneko, Satoshi Yoshida, Hajime Mita, Hikaru Yabuta, Akihiko Yamagishi (2012): Formation, Alteration and Delivery of Exogenous High Molecular Weight Organic Compounds: Objectives of the Tanpopo Mission from the Point of View of Chemical Evolution.  Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology Japan, 10 (ists28), Tp_7-11.  doi: 10.2322/tastj.10.Tp_7
  • Palash K. Sarker, Jun-ichi Takahashi, Yukinori Kawamoto, Yumiko Obayashi, Takeo Kaneko, Kensei Kobayashi (2012): Photostability of Isovaline and its Precursor Molecule Exposed to Simulated Space Radiation.  International Journal of Molecular Sciences, 13(1), 1006-1017.  doi:10.3390/ijms13011006
  • Chui Wei Bong, Yumiko Obayashi, Satoru Suzuki (2011): Effect of exposure of zinc at low concentration to bacterial production in seawater.  Memoirs of Faculty of Agriculture, Ehime University, 56, 41-45.
  • Yumiko Obayashi, Nahomi Ueoka, Satoru Suzuki (2010): Degradation and utilization of protein derived from Pseudomonas aeruginosa by marine microbial community.  Journal of Oceanography, 66, 513-521.  doi: 10.1007/s10872-010-0043-7
  • Chui Wei Bong, Francesca Malfatti, Farooq Azam, Yumiko Obayashi, Satoru Suzuki (2010): The effect of zinc exposure on the bacteria abundance and proteolytic activity in seawater  In: N. Hamamura, S. Suzuki, S. Mendo, C. M. Barroso, H. Iwata and S. Tanabe (eds.), Interdisciplinary Studies on Environmental Chemistry, Vol. 3, Biological Responses to Chemical Contaminants: From Molecular to Community Level, TERRAPUB, Tokyo, 57-63.
  • Chui Wei Bong, Yumiko Obayashi, Satoru Suzuki (2009): Changes in proteolytic activities in stored seawater and bacterial isolates.  In: Y. Obayashi, T. Isobe, A. Subramanian, S. Suzuki, S. Tanabe (eds.), Interdisciplinary Studies on Environmental Chemistry, Vol. 2, Environmental Research in Asia for Establishing a Scientist's Network, TERRAPUB, Tokyo, 287-291.
  • Kwang-Hyeon Chang, Hideyuki Doi, Yuichiro Nishibe, Yumiko Obayashi, Shin-ichi Nakano (2009): Spatial and temporal distribution of zooplankton communities of coastal marine waters receiving different human activities (fish and pearl oyster farmings).  The Open Marine Biology Journal, 3, 83-88.  doi: 10.2174/187445080903010083
  • Yumiko Obayashi, Satoru Suzuki (2008): Adsorption of extracellular prtoteases in seawater onto filters during size fractionation.  Journal of Oceanography, 64, 367-372.  doi: 10.1007/s10872-008-0029-x
  • Yumiko Obayashi, Satoru Suzuki (2008): Occurrence of exo- and endopeptidases in dissolved and particulate fraction of coastal seawater.  Aquatic Microbial Ecology, 50, 231-237.  doi: 10.3354/ame01169
  • Hideyuki Doi, Kwang-Hyon Chang, Yumiko Obayashi, Mizuho Yoshihara, Mary Shime, Takako Yamamoto, Yuichiro Nishibe, Shin-ichi Nakano (2008): Attached microalgae contribute to planktonic food webs in bays with fish and pearl oyster farms.  Marine Ecology Progress Series, 353, 107-113.  doi: 10.3354/meps07202
  • Yumiko Obayashi, Satoru Suzuki (2007): Microbial degradation of organic matter in seawater –Insights from the activity of proteolytic enzymes–  In: S. Tanabe, H. Takeoka, T. Isobe, Y. Nishibe (eds.), Chemical Pollution and Environmental Changes, Universal Academy Press, Tokyo, 311-313.
  • Toshiya Katano, Atsushi Kaneda, Naoto Kanzaki, Yumiko Obayashi, Akihiko Morimoto, Goh Onitsuka, Hideichi Yasuda, Sotaro Mizutani, Yoshihide Kon, Kazuhiro Hata, Hidetaka Takeoka, Shin-ichi Nakano (2007): Distribution of prokaryotic picophytoplankton from Seto Inland Sea to the Kuroshio region, with special reference to ‘Kyucho’ events.  Aquatic Microbial Ecology, 46, 191-201.  doi: 10.3354/ame046191
  • Yumiko Obayashi, Satoru Suzuki (2005): Proteolytic enzymes in coastal surface seawater: Significant activity of endopeptidases and exopeptidases.  Limnology and Oceanography, 50, 722-726.  doi: 10.4319/lo.2005.50.2.0722
  • Yumiko Obayashi, Eiichiro Tanoue (2002): Growth and mortality rates of phytoplankton in the northwestern North Pacific estimated by the dilution method and HPLC pigment analysis.  Journal of Experimental Marine Biology and Ecology, 280, 33-52.  doi: 10.1016/S0022-0981(02)00365-9
  • Yumiko Obayashi, Eiichiro Tanoue, Koji Suzuki, Nobuhiko Handa, Yukihiro Nojiri, Chi Shing Wong (2001): Spatial and temporal variabilities of phytoplankton community structure in the northern North Pacific as determined by phytoplankton pigments.  Deep-Sea Research I, 48, 439-469.  doi: 10.1016/S0967-0637(00)00036-4

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