Accumulation of streptomycin-phosphate in cultures of streptomycin producers grown on a high-phosphate medium.

A phosphorylated derivative of streptomycin accumulated in cultures of Streptomyces griseus ATCC 12475 and SC2376 grown on complex media containing an excess of inorganic phosphate (0.01 m). This compound did not accumulate significantly in the absence of added inorganic phosphate. The phosphorylated derivative did not inhibit growth of Bacillus subtilis or support growth of a streptomycin-dependent strain of Escherichia coli; however, incubation of the derivative with alkaline phosphatase gave a compound which was active with both systems. In the phosphorylated derivative, phosphate is esterified with an -OH group of the streptidine moiety of streptomycin. It is suggested that the phosphoryl group is introduced during biosynthesis of the streptidine moiety of streptomycin or by the action of streptomycin kinase on preformed streptomycin (or both), and subsequent dephosphorylation by streptomycin-phosphate phosphatase is inhibited by high concentrations of inorganic phosphate. A column chromatographic procedure for separation of streptidine-phosphate, streptomycin-phosphate, and streptomycin is described.