Abstract
The degree of heat sensitization induced in spores of Bacillus subtilis by irradiation with gamma rays was not changed when irradiation was carried out at low oxygen tension (1 mm of Hg) as compared with irradiation in an air atmosphere. The degree of heat sensitization appeared to be slightly greater at pH 7.0 than at pH 4.5. The substrate was found to influence the degree of induced heat sensitivity with less of an effect produced in complex organic substrates.