[Temperature-dependent mutants of Bacillus subtilis A-50 with a diminished level of alkaline proteinase synthesis]

Temperature-sensitive proteolytically inactive mutants of Bacillus subtilis A-50 are obtained. The optimal ability to synthetise the enzyme both in the original strain and in mutants is expressed at 37 degrees C. The level of proteolytic activity of selected prot(ts) mutants depends both on the temperature of growth and on the temperature at which the activity of subtilisin is analysed. The optima of functioning ts-proteinases are shifted in mutants as compared with the original strain. The ability to form spores at 37 degrees C and 45 degrees C are considerably reduced as compared with this process at 28 degrees C. The results of disc electrophoresis in polyacrylamide gel indicate the presence of structural alteration of proteinases in the mutants obtained.