[Characteristics of Bacillus thuringiensis Berliner mutants, resistant to tetracycline, having retained or lost the ability to sporulate].

Quantitative analysis of extracellular protease, NADH-oxydase and glucose-deshydrogenase show that, from two mutants selected by their oxytetracycline resistance, one sporulates better than the parent strain, the other, which sporulates at 10(-5), has a stable extracellular protease activity and appears to be blocked at stage O-I.