[Catalase and superoxide dismutase activity in isogenous bacterial strains with different degrees of radioresistance].

Superoxide dismutase and catalase activity has been studied in isogenous strains of various radioresistance bacteria. In mutants Micrococcus radiodurans having defects in the systems of DNA repair the superoxide dismutase activity is lower than in cells of wild type. The changes of catalase and superoxide dismutase activity have not been revealed in investigated strains Escherichia coli differing in radioresistance. It has been concluded that the survival of bacteria exposed to ionizing radiation is determined by the effectiveness of DNA repair systems realiability of which depends on the catalase and superoxide dismutase activity.