The formation of the exoenzymes, neutral and alkaline proteinase as well as alpha-amylase of Bacillus subtilis, is characterized by the same time course. The exoenzyme formation starts in the exponential phase of growth by an excess of C and N sources. We assume that carbon metabolism of pyruvate is responsible for the exoenzyme formation during this growth phase. The proteinase formation at the transient and/or stationary phase of growth is related to amino acid limitation.
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.
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