Radiosensitivity of Bacillus subtilis under Different Environmental Conditions

Abstract
The radiosensitivity of spores of B. subtilis irradiated with high-energy (3 mev) cathode rays is greatest in an atmosphere of O2; it is decreased in air, N2, and vacuum. Lyophilized samples are somewhat less radiosensitive than liquid samples; frozen samples are more radiosensitive than non-frozen samples. When irradiated in pea purge or in evaporated milk, B. subtilis is more radiosensitive than when irradiated in saline suspension. Radiosensitivity appears to be decreased by the use of Na ascorbate in saline and in the pea puree suspensions. The pH of the solution has no clear cut effect. Age of culture may play a role in the magnitude of the effect of any of these factors.