DISCOVERY, PRODUCTION, AND BIOLOGICAL ASSAY OF AN UNUSUAL FLAVENOID COFACTOR INVOLVED IN LINCOMYCIN BIOSYNTHESIS

In a genetic study of Streptomyces lincolnensis , a riboflavin auxotroph, NTG-3, was obtained which was also a lincomycin non-producer under standard antibiotic production conditions. The addition of small amounts of sterile-filtered fermentation broth from a second non-producing S. lincolnensis mutant, NTG-5, fully restores the ability of NTG-3 to produce lincomycin. This response of the mutant NTG-3 was exploited in a biological assay to facilitate the isolation of "lincomycin cosynthetic factor" (LCF) found in the mutant NTG-5 and to determine in which part of the lincomycin biosynthesis pathway the factor functions. The isolation and characterization of the LCF from S. lincolnensis is the subject of the following note.