Continuous Culture Studies on the Biosynthesis of Alkaline Protease, Neutral Protease and -Amylase by Bacillus subtilis NRRL-B3411

Abstract

SUMMARY: The amounts of three catabolite repressible enzymes, alkaline protease, neutral protease and α-amylase, produced by Bacillus subtilis NRRL-B3411 growing in a chemostat, depended on the growth-limiting substrate. Limiting growth with glucose was advantageous for α-amylase synthesis while nitrogen-limited growth was advantageous for synthesis of the two proteases. Under the conditions used, continuous cultures were unsuitable for large-scale production of the three enzymes since spontaneous mutations to less productive strains occurred in the long term.