Hiroshima University Faculty of Applied Biological Science
Hiroshima University Graduate School of Biosphere Sciences
Hiroshima University Graduate School of Biosphere Sciences
Hiroshima University Graduate School of Biosphere Sciences
Hiroshima University Faculty of Applied Biological Science
Hiroshima University Faculty of Applied Biological Science
Hiroshima University Graduate School of Biosphere Sciences
National Institute of Polar Research
Japan Atomic Energy Agency
Yokohama National University Graduate School of Engineering
出版者
宇宙航空研究開発機構宇宙科学研究本部
出版者（英）
Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA/ISAS)
雑誌名
宇宙利用シンポジウム 第24回 平成19年度
雑誌名(英)
Space Utilization Research: Proceedings of the Twenty-fourth Space Utilization Symposium
ページ
314 - 317
発行年
2008-03
抄録（英）
Microbial cells were irradiated with high-dose X-ray (0.2 nm, 500 R/s) for 0 to 1.2 x 10(exp 7) R and high-energy Fe ions (500 MeV/u) for 0 to 2,000 Gy to examine their survivability based on the biological 'energy currency', i.e., Adenosine 5'-Triphosphate (ATP), and the Colony-Forming Units (CFU). The well known radiation-resistance bacterium Deinococcus radiodurans and Escherichia coli X1488 and non-cellular ATP were used for X-ray irradiation. On the other hand, Deinococcus radiodurans and two spore-forming bacterium Virgibacillus and four strains of Escherichia coli (each strain of Escherichia coli have another radiation-sensibility) were used for Fe ion irradiation. The results of X-ray irradiation were: (1) Cellular ATP showed highest survivability in the D.radiodurans and celluar ATP decreased exponentially. Whether non-celluer ATP did proportionally. (2) D.radiodurans survived extremely high-dose of X-ray. The lethal dose was several thousands greater than that of E.coli. The results of Fe ions radiation were (1) Cellular ATP decreased exponentially but only D.radiodurans's did proportionally. (2) CFU of E.coli and D.radiodurans showed rapid decrease at the dose of over 50 Gy. However, only D.radiodurans survived at the dose of 2000 Gy. These results suggest that (1) Irradiation of X-ray and Fe causes another effect on microbial cells. Fe ions showed greater effect on microbial cells than X-ray. (2) Each bacterium has their characteristic radiation resistance such as DNA repair capability or spore forming. More different radiation type and more bacteria strains should be used in future study.
大線量X線およびFeイオン照射の照射に対する放射線耐性微生物の生残に関する予察的研究
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