Isolation and characterization of Tn917-generated bacitracin deficient mutants of Bacillus licheniformis

Abstract Two Tn917-generated bacitracin deficient mutants of Bacillus licheniformis were isolated. Southern blot analysis of chromosomal DNA extracted from both insertional mutants showed that Tn917 inserted in the vicinity of the gene coding for the enzyme BA2 of the bacitracin synthetase enzyme complex. Measurements of bacitracin synthetase activity in cell-free extracts and positive hybridization signals in the vicinity of the BA2 gene indicate that in both bacitracin deficient mutants Tn917 could be inserted in the BA1 gene or in segments involved in regulation. Thus, it could be possible that the genes for bacitracin synthetase are clustered in the B. licheniformis genome.