Studies on the Media for Enterotoxin Production and Sporulation by Clostridium perfringens

Abstract

The present study Was aimed at obtaining a suitable medium for enterotoxin production and sporulation by Clostridium perfringens. Using both heat-stable (NCTC 8798) and heatlabile (TCW-224-1) strains, various nutritional ingredients were taken into considaration for enterotoxin production as well as sporulation.1. Various peptones, carbohydrates and meat infusions were examined for enterotoxin production, among which polypeptone S (Daigo), soluble starch and chicken meat infusion had the most enhancing effects on enterotoxin production. The appropriate pH range after cultivation was from 4.8 to 6.8, 6.2 being optimum.2. From the results described above, a new medium having following composition was established. Soluble starch, 5g; NaCl, 5g; Na2HPO4, 5g; FeCl3·6H2O, 10mg; sodium thioglycolate, 1g; in 1 liter chicken meat infusion. The pH of chicken meat infusion was adjusted to 7.5, autoclaved and filtered before the addition of other ingredients. This new medium was filtered after heating and autoclaved as usual.3. When various kinds of media were used, enterotoxin production by NCTC 8798 strain was detectable at spore numbers as small as 10/ml in culture, and the amount of enterotoxin seemed to increase as spore numbers increased. In a few instances, however, no enterotoxin was detected even at spore numbers of 105-7/ml in culture, meaning that, when enterotoxin is well produced, good sporulation usually occurs in the medium, and that the reverse is not always true. This implies that the quality of spores in addition to quantity or the degree of maturation in the sporulation stage, must also be taken into account for the enterotoxin production by this organism.