[Cooperative functioning of 2 systems of protection against its own antibiotic in Str. erythreus 1571, a superproducer of erythromycin].

Protein synthesis in the mycelium of various ages and the protoplasts of Str. erythreus 1571 was slightly sensitive even to high concentrations of erythromycin and lincomycin. Oxytetracycline and neomycin in low concentrations induced marked inhibition of the protein synthesis. 14C-Erythromycin was binding with the mycelium of the organism producing it in much lower amounts than with the mycelium of Str. roseolus, a lincomycin-producing culture. No products of erythromycin biotransformation by the cell-free preparations of Str. erythreus containing cofactors for enzymatic phosphorylation and demethylation were detected with the methods of microbiological titration and radiochromatography. Enzymatic N-demethylation of lincomycin was observed in the cell-free preparations of Str. erythreus. Erythromycin and lincomycin had practically no effect on polylysine synthesis in the cell-free system of Str. erythreus with poly-A and inhibited the synthesis of this polypeptide in the cell-free systems of E. coli MRE 600 and B. subtilis ATCC 6633. These antibiotics had either no effect on the fragment (puromycin) reaction with the ribosomes of Str. erythreus. In case of the ribosomes of E. coli MRE 600 the fragment reaction was sensitive to lincomycin but not to erythromycin. The ribosomes isolated from Str. erythreus and their 50S subunits bound 14C-erythromycin in much lower amounts than those isolated from E. coli and their 50S subunits. The data are indicative of the presence of 2 systems protecting the culture from erythromycin in Str. erythreus 1571, i.e. at the level of ribosomes and at the level of the cytoplasmic membrane.