Sporulation and enterotoxin production by Clostridium perfringens type A under conditions of controlled pH and temperature.

Abstract

The effect of two environmental factors, pH and temperature, on sporulation and enterotoxin production in Clostridium perfringens type A was determined. A maximum level of enterotoxin was obtained in Duncan and Strong sporulation medium when the pH was not controlled by external addition of NaOH. Slightly lower levels were obtained when the pH was controlled at 7.0. Percentage of sporulation and heat-resistant spore population levels were similar at pH 7.0 and when the pH was not externally controlled. Enterotoxin concentration, percentage of sporulation, and heat-resistant spore levels decreased greatly when the pH was kept at 8.0, 8.5, and 6.0. At pH 5.5 vegetative growth occurred although sporulation and enterotoxin production did not. Levels of heat-resistant spores and enterotoxin were higher at 37C than at 25, 30, or 43C. Enterotoxin formation was not detected at 46C.