Physiology of toxin production by Clostridium botulinum types A and B. III. Effect of pH and temperature during incubation on growth, autolysis. and toxin production.

and inositol was no greater than in the control medium which contained no added carbohydrate. Growth and toxin synthesis by strain JDT-I1V, which may be taken as representative for all the strains tested, are presented graphically in figure 1 and 2, respectively. Although equal growth rates were observed during the exponential growth phase with all the carbohydrates, maximum growth was achieved only with glucose and maltose. The degree to which growth was repressed with the other carbon compounds when compared to glucose, however, was not sufficient to account for the extreme differences in toxin production. It can also be noted that autolysis of the culture did not go to completion unless glucose or maltose was included in the growth medium. Sonic disintregation of the intact cells, which remained after 72 hr of incubation in the media containing carbohydrates other than glucose and maltose, did not result in the increased toxicity of the supernatant fluid showing that the toxin was not present intracellularly. SUMMARY