Formation of Bacitracin by Washed Cell Suspensions of Bacillus Licheniformis.

Although the microbial formation of a variety of polypeptides possessing antibiotic activities has been known for some time, the biosynthesis of these compounds has as yet received little attention. Not only is the mechatnism of formation of these biologically active compounds of interest in itself, but the biosyntheses of these polypeptides are potential systems for investigating the general problem of peptide bond formation. The synthesis of the polypeptide bacitracin appeared particularly interesting since this compound contains not only nine different a-peptide linkages, but also a thiazoline ring and two unusual peptide linkages involving in one case the c-amino group of lysine and in the other the 3-carboxyl group of aspartic acid. (Lockhart and Abraham, 1956; Lockhart, Abraham, and Newton, 1955; Hausmann, Weisiger, and Craig, 1955; Weisiger, Hausmann, and Craig, 1955). As the initial step in the investigation of bacitracin synthesis, a study of the formation of this compound by washed cell suspensions of Bacillus licheniformis has been carried out.