Japan Geoscience Union Meeting 2015

Presentation information

International Session (Oral)

Symbol B (Biogeosciences) » B-AO Astrobiology & the Origin of Life

[B-AO01] Astrobiology: Origins, Evolution, Distribution of Life

Wed. May 27, 2015 4:15 PM - 6:03 PM 105 (1F)

Convener:*Kensei Kobayashi(Department of Chemistry and Biotechnology, Faculty of Engineering, Yokohama National University), Akihiko Yamagishi(Tokyo University of Pharmacy and Life Science, Department of Molecular Biology), Masatoshi Ohishi(Astronomy Data Center, National Astronomical Observatory of Japan), Eiichi Tajika(Department of Complexity Science and Engineering, Graduate School of Frontier Sciences, The University of Tokyo), Takeshi Kakegawa(Graduate School of Science, Tohoku University), Shigeru Ida(Department of Earth and Planetary Science, Graduate School of Science and Technology, Tokyo Institute of Technology), Chair:Takeshi Kakegawa(Graduate School of Science, Tohoku University), Shigeru Ida(Department of Earth and Planetary Science, Graduate School of Science and Technology, Tokyo Institute of Technology)

5:30 PM - 5:33 PM

[BAO01-P02] Survivality of deinococci under space conditions ? Toward the space exposure experiment in "TANPOPO" mission at ISS

3-min talk in an oral session

*Yuka MURANO1, Miyu HARADA1, Yuko KAWAGUCHI2, Hirofumi HASHIMOTO2, Kensei KOBAYASHI3, Kazumichi NAKAGAWA4, Issay NARUMI5, Katsuya SATO6, Satoshi YOSHIDA7, Hajime YANO2, Shin-ichi YOKOBORI1, Akihiko YAMAGISHI1 (1.Dept. Applied Life Sci., Sch. Life Sci., Tokyo Univ. Pharm. Life Sci., 2.JAXA/ISAS, 3.Grad. Sch. Engineer., Yokohama Natl. Univ., 4.Grad. Sch. Human Develop. Environ., Kobe Univ., 5.Facl. Life Sci., Toyo Univ., 6.Quantum Beam Sci. Cen., JAEA, 7.Natl. Inst. Radiological Sci.)

Keywords:International Space Station, Panspermia, Microbe space exposure experiment, "Tanpopo" mission

The "panspermia hypothesis" has been proposed as one of the hypotheses on the origin of terrestrial life. In this hypothesis, possible interplanetary migration of microbes has been considered.
To address the question whether interplanetary migration of terrestrial microbes are possible, we have proposed and prepared the space capture and space exposure experiments of terrestrial microbes as two of six sub-themes of "TANPOPO mission" on the Exposure Faculty of Japanese Experiment Module "KIBO" of International Space Station (ISS) (Yamagishi et al., 2008). In this mission, we are going to expose microbes in space for one to three (or more) years. There are harsh environmental factors (vacuum, high UV irradiation, ionization radiation, and so on) in space. We have selected the species that show high tolerance to the space conditions.
We are going to use UV- and radiation-resistant deinococcal species: four stains of Deinococcus radiodurans (R1, KH311, rec30, and UVS78), Deinococcus aerius TR0125, and Deinococcus aetherius ST0316. D. aerius and D. aetherius were isolated from upper troposphere and lower stratosphere, respectively (Yang et al. 2009, 2010). They showed high tolerance to UV and radiation, similar to or higher than D. radiodurans R1. In addition, since the DNA repair systems are known to be the keys of high tolerance to UV and radiation in deinococcal species, space survivability of D. radiodurans R1 (wild type strain) will be compared with those of the DNA repair deficient mutant strains of D. radiodurans, KH311 (deficient mutant strain of pprA gene for non-homologous end-joining (NHEJ) repair), rec30 (deficient mutant strain of recA gene for homologous recombination), and UVS78 (deficient mutant strain of uvdE and uvrA1 genes for nucleotide excision repair).
In this paper, we sumarize survivability of deinococcal species for UV-irradiation, heavy ion-irradiation, high vacuum, and periodical change of temperature. Then, we evaluate survivability of deinococcal species in space after one year.

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Yang, Y., Internatl. J. Syst. Evol. Microbiol. 60: 776-779