Elevation of the heat resistance of vegetative cells and spores of Clostridium perfringens type A by sublethal heat shock

The degree of heat resistance conferred on Clostridium perfringens by a heat shock, the kinetics of this development, and its duration were determined. A sublethal heat shock at 55 degrees C for 30 min increased the heat tolerance of vegetative cells at least two-to threefold, The acquired tolerance was maintained for 2 h after the heat shock treatment. Heat shock applied for the first hour of incubation produced spores more tolerant to heat than the spores of the control. Acquired thermotolerance is of importance in the case of this organism because of its inherently high optimal growth temperature.