Biosynthesis of polyketomycin produced by Streptomyces diastatochromogenes Tü 6028.

The biosynthesis of polyketomycin was investigated by feeding 13C-labeled acetate and propionate to the growing cultures of Streptomyces diastatochromogenes Tü 6028. 13C NMR spectral analysis demonstrated the polyketide origin of the aglycone and the dimethylsalicyloyl moieties. The O-methyl group and 6-CH3 of the aglycone as well as 3B-CH3 of L-axenose and 3C-CH3 of the salicyloyl residue were labeled by feeding L-[methyl-13C]methionine. Both deoxysugars emerged from D-glucose. The biosynthesis of the aglycone and the assembly of the glycoside are discussed. The polyketomycin producing strain may be a candidate for further exploration in combinatorial biosynthesis.