THE INFLUENCE OF Bacillus subtilis PROTEINS DegU, SinR AND SinIR ON BACITRACIN BIOSYNTHESIS IN Bacillus licheniformis

Abstract

A vast array of natural peptides diverse in their structure that are produced by microorganisms living in different aquatic and terrestrial environments are not gene encoded but are synthetized nonribosomally on peptide synthetases. The branched cyclic dodecyl peptide antibiotic bacitracin, produced by special strains of Bacillus, is synthesized nonribosomally by a large multienzyme complex composed of the three bacitracin synthetases BA1, BA2 and BA3. The rate of peptide antibiotic bacitracin biosynthesis positively correlates with the level of the alkaline protease production. To define some positively acting factors in terms of bacitracin production we performed an experiment expressing genes involved in the process of sporulation and competence (B. subtilis): degU on pBD1834, sinIR on pIS74 and sinR on pIS119 in B. licheniformis. Bacterial clones were analyzed for the proteolytic activity and bacitracin production. In 9 clones (2 x pBD1834, 2 x pIS74 in 5 x pIS119) higher rate of the peptide antibiotic bacitracin production was determined.