COMPARISON OF SURVIVOR CURVES OF BACILLUS - SUBTILIS SPORES SUBJECTED TO WET AND DRY HEAT

SUMMARY: Survivor curves for spores of Bacillus subtilis were determined in wet and dry heat over a wide range of temperatures. Wet heat tests were determined using a thermoresistometer and thermal death time cans. Dry heat tests were conducted in a closed system using thermal death time cans. There were major differences in the shape of the wet vs. dry heat survivor curves. Wet heat resulted in convex curves at low temperatures, but a straight line at higher temperature. Dry heat resulted in concave curves at all temperatures. These results suggest that physiological differences exist between wet and dry heat destruction of bacteria. Several possible explanations for the difference in the shape of the survivor curves were discussed. Copyright © 1969, Wiley Blackwell. All rights reserved