BIOCHEMICAL CHANGES OCCURRING DURING GROWTH AND SPORULATION OF BACILLUS CEREUS

Abstract

In a glucose, ether extracted yeast extract, salts medium, B. cereus was observed to dissimilate glucose during growth to organic acid intermediates which accumulated in the medium. Analysis of the supernatant revealed that the principle acid produced during growth is acetate. accounting for 60-65% of the glucose carbon. Once sporulation begins, the accumulated acetate is rapidly utilized. This accumulation of acetate during growth and its rapid utilization during sporulation were shown to be responsible for the characteristic pH changes observed in these cultures. These results, together with other data, suggest that one of the initial changes during the transition phase between vegetative growth and sporulation is the induction of a system capable of utilizing acetate, a mechanism believed to be essential for the completion of the sporulation process in a glucose medium.