ENZYMATIC CHANGES DURING SPOROGENESIS IN SOME AEROBIC BACTERIA

Abstract

17 enzymatic systems, demonstrable in vegetative cellular extracts of Bacillus mycoides and other aerobic spore-forming bacilli, could not be detected in spore cell extracts tested concomitantly. These results support the hypothesis that sporogenesis occurs at the expense of (enzyme) proteins preexisting in the vegetative cell. The latter apparently are sacrificed almost completely. The rate of destruction is selective; some enzymes, notably those involved in carbohydrate oxidative metabolism, are lost much faster than others, for example, those dealing with amino acid metabolism. The latter probably persist adaptively because their specific substrates are involved in the sporogenesis, whereas the oxidative enzymes in the absence of specific substrates are destroyed early. Degradation of the oxidative enzymes presumably furnishes the substrates for the amino acid enzymes. In the presence of carbohydrate as a substrate the enzymes concerned with its metabolism are preserved substantially, and the cell persists in the vegetative state.