[Kinetics of germ killing and damage to selected bacterial enzymes by thermal and chemical influences. II. The thermoresistance of Bacillus subtilis compared to the thermostability of enzymes of this species].

The influence of moist heat on the recultivation of Bacillus subtilis-spores and on the thermal inactivation of two enzymes prepared from this species was investigated. The velocity constant k of destroying microorganisms (determination by counts of B. subtilis-spores with microbiological methods) and the specific activity (determination by biochemical methods) of creatine kinase (EC 2.7.3.2.) and aminopeptidase (EC 3.4.11.2.) were compared. A significant correlation between the logarithm of specific activity and the velocity constant (k/2,303 = 1/D) was found. A thermal exposition for 15 min and 105 degrees C was sufficient for the total inhibition of the activity of creatine kinase and aminopeptidase in the intact spores of B. subtilis.