The effect of air on the moist-heat resistance of Bacillus stearothermophilus spores.

The presence of air in an autoclave chamber and load is generally considered to reduce the lethal effect of the process on bacterial spores. In this study, the heat inactivation of spores of Bacillus stearothermophilus (NCIB 8224) was measured in the presence and absence of air at 100% relative humidity. The results confirm that air significantly enhances the lethality of moist-heat on this strain of B. stearothermophilus.