Fatty acids and production of tylosin-like compounds in Streptomyces fradiae

Taxonomic studies of Streptomyces virginiae mutants overproducing virginiamycin M1

By using both the traditional International Streptomycetes Project methods and chemical approaches followed by a hierarchical cluster analysis, Streptomyces virginiae mutants A-1 and B-43 (yielding higher amounts of the M1 component of virginiamycin complex), their wild ancestor ATCC 13161, and another virginiamycin producer, S. pristinaespiralis NRRL 2958, were subjected to taxonomic studies to find kinship or differences among the strains. Of the methods used, only the test of carbon utilization, investigation of spore surface and analysis of sugar constituents of cell walls proved to be reliable enough to demonstrate the species identity of S. virginiae strains and to distinguish them from S. pristinaespiralis. L,L-2,6-Diaminopimelic acid was present in all strains. Analysis of fatty acids and total proteins as well as investigations of morphology and pigmentation of agar cultures led to confusing results.

Relationship between the fatty acid composition and the type of antibiotics produced by Streptomyces lasaliensis

The GC-MS method was used to analyze fatty acids in a parent strain of Streptomyces lasaliensis and its two mutants producing only lasalocid or quinomycin. The biosynthesis of these substances bears relation to differences in the relative proportion of fatty acids. Biosynthetic relationships were revealed between the starter fatty acid units, their precursors, i.e. valine, leucine and isoleucine, and the type of the antibiotic produced.