[Effect of proteins on exoprotease synthesis by Bacillus thuringiensis]

Bacillus thuringiensis was shown to grow better in media with albumin, gelatin and casein than in a chemically defined medium; proteins did not induce the synthesis of exoprotease. Two maxima were found in the enzyme synthesis: the first one at the exponential phase of the cultural growth, and the second one during spore formation by the culture. The synthesis at the exponential growth phase was susceptible to nitrogen metabolite repression while the synthesis of exoprotease at the stationary phase of growth was not repressed in the presence of high concentrations of ammonium ions in the medium.