Streptomycin-phosphorylating Enzyme Produced by Streptomyces griseus

Streptomycin-phosphorylating enzyme was reported previously to be produced in mycelium of Streptomyces griseus HUT 6037 at late stage of growth. In the present investigation, this enzyme was purified 200 times as high in specific activity as cell-free extract by means of salting out, chromatography on DEAE-Sephadex A-25 and gel filtration with Sephadex G-100. This enzyme was most stable at pH 8.0 and required 10^?2mMg²⁺ in the reaction mixture for the highest activity. It lost the activity by heat treatment at 40°C for 15 min in absence of the substrate.

Mutant cultures were prepared on productivity of or tolerance to streptomycin, and their capacity to produce streptomycin-phosphorylating enzyme was examined. The cultures which had low to no capacity to produce streptomycin produced a small amount to none of the enzyme, suggesting that production of the streptomycin-phosphorylating enzyme had some correlation with streptomycin productivity of the culture. But no definite correlation was observed between productivity of the enzyme and the capacity to tolerate streptomycin.