Viva Origino
Online ISSN : 1346-6933
Print ISSN : 0910-4003
35 巻, 3 号
  • 齊藤 剛
    2007 年 35 巻 3 号 p. 85-92
    発行日: 2007年
    公開日: 2022/01/18
    ジャーナル フリー

      Some terrestrial microorganisms can survive in extremely severe environments, such as high temperature, high salt, strong acid and strong alkali condition. Elucidation of the adaptive mechanisms of these extremophiles against extreme environments will provide very meaningful information to consider the evolution and the diversity of organisms. Some bacteria show considerably high resistance to ionizing radiation. D37 of Escherichia coli is 40 Gy, while D37 of Deinococcus radiodurans which is representative radioresistant bacterium is 7 kGy. D37 is the dose required to leave 37% of the original population viable. It is thought that radioresistances of radioresistant bacteria depend on high DNA repair activities, high antioxidant activities, special cell structures and uncommon intracellular environments. Information of radioresistant mechanisms in these bacteria will be helpful for elucidation of protective mechanisms of organisms against the stresses to damage cellular constituents. This review deals with recent advances in the study of the radioresistant mechanisms in the radioresistant bacteria.