Effects of 60Co Gamma-Rays, Ultraviolet Light, and Mitomycin C on Halobacterium salinarium and Thiobacillus intermedius

Abstract

Lethal effects of 60Co γ-rays, UV light, and mitomycin C on two kinds of bacteria, Halobacterium salinarium which grows in highly concentrated salt media and Thiobacillus intermedius which requires reduced sulfur compounds, were studied and compared with those on Escherichia coli B/r. D37 values for H. salinarium, T. intermedius and E. coli B/r were 393, 150, and 92 Gy, respectively, by exposure to 60Co γ-rays. They were 212, 38, and 10 J/m2, respectively, by exposure to UV light and 2.36, 0.25, and 0.53 μg/ml/h, respectively, by exposure to mitomycin C. Against these agents, H. salinarium was much more resistant than T. intermedius and E. coli B/r.