Biosynthesis of gramicidin and tryocidine in the Dubos strain of Bacillus brevis. I. Experiments with growing cultures.

Okuda, Kiyoshi (Department of Biochemistry and Biophysics, University of Hawaii, Honolulu), Gordon C. Edwards, and Theodore Winnick. Biosynthesis of gramicidin and tyrocidine in the Dubos strain of Bacillus brevis. I. Experiments with growing cultures. J. Bacteriol. 85:329-338. 1963.-A simple chromatographic method was developed for the isolation of gramicidin and tyrocidine from tyrothricin of Bacillus brevis. A Tryptone-yeast extract-glucose medium containing mineral salts gave the best yields of peptides in a stationary culture of the organism. The incorporation of suitable C(14)-labeled amino acids into gramicidin and tyrocidine was studied Several analogues of tyrocidine amino acids (beta-hydroxyglutamic acid, pipecolic acid, beta-2-thienylalanine, p-fluorophenylalanine, and phenyl glycine) selectively reduced tyrocidine synthesis, when added to the nutrient medium. At the same time, the production of gramicidin was augmented. Growth and protein synthesis were not affected. Two analogues in isotopic form, beta-2-thienylalanine and isoleucine, were shown to give rise to high degrees of labeling in tyrocidine.