Formation of extracellular neutral proteinase and the stringent response in Bacillus subtilis

The kinetics of extracellular neutral proteinase synthesis by an isogenic stringent (IS58) and a relaxed (IS56) strain of B. subtilis were compared. The specific enzyme formation rate by the stringent strain was higher than that of the relaxed one. Norvaline addition (1 mg/mL) induced the formation of pppGpp and ppGpp, respectively, as well as the appearance of extracellular neutral proteinase activities in cultures of the stringent strain IS58 and a strain with high proteinase production (ZF-178) only. These correlations support the suggestion that (p)ppGpp are involved in the regulation processes responsible for production of extracellular neutral proteinases by B. subtilis.