[Disordered bacitracin synthesis and sporulation in mutant Bacillus licheniformis with decreased proteolytic...

The vegetative cells of B. licheniformis, producing bacitracin, a feed grade peptide antibiotic were exposed to nitroso guanidine and six mutants with lowered activity of serine exoprotease in the culture fluid were isolated. It was found that synthesis of bacitracin and sporulation of the mutants were impaired. The cause of the impairment is not known. The results are discussed from two viewpoints: serine exoprotease is responsible for positive regulation of bacitracin biosynthesis and sporulation at the account of forming an amino acid pool in the medium, simultaneous changing of the three features in the mutants may be due either to a single pleiotropic mutation or to multiple mutations independently induced by nitroso guanidine.