Abstract
Life times of radiosensitive strains of Escherichia coli and Saccharomyces cerevisiae have been obtained with logarithmic and stationary phase cells at various temperatures. The results of temperature dependence of mortality rate were well described by the first order chemical reaction formula (Arrhenius equation). In the case of E. coli JC 1569 b rec- and its original rec+ strains, the difference in survival curves between them appeared only in logarithmic phase cells and was described as a difference in energy independent term in the Arrhenius equation. These results have suggested that these rec+ and rec- strains have a recovery mechanism but the rec- strain could not repair the damage enough to survive during exponential growth and/or tolerate the injury for a subsequent DNA replication and growth.
