Effect of cyclic AMP on catabolite repressed bacterial sporogenesis of an anaerobe

Abstract

The sporulation of a high frequency sporogenic mutant of Clostridium botulinum was reduced to less than 30% in a medium containing 270 mM glucose. The repression was reversed from 30 to greater than 80% sporulation by the addition of 10(-5) or 10(-4) M cyclic 3',5'-adenosine monophosphate (cAMP) or monobutyrul cyclic AMP (B-cAMP). No difference was observed in amount of growth with the addition of either the cAMP or B-cAMP. Glucose consumption was enhanced by the addition of either of the cyclic nucleotides and corresponding changes in pH were observed. The catabolite repression by glucose was reversed by ATP or ADP. Except for GTP, guanine nucleotides were not effective. The intracellular cyclic AMP levels were high in vegetative, sporulating and derepressed cells, but low in glucose-repressed cells. The findings suggest that the sporulation of the anaerobe was sensitive to catabolite repression which was specifically reversed by cyclic AMP.