[Dynamics of protein biosynthesis in a Streptomyces erythreus culture and its alteration as affected by exogenous erythromycin]. / Dinamika biosinteza belka v kul'ture Streptomyces erythreus i ee izmenenie pod deistviem ékzogennogo éritromitsina.

The intensity of protein biosynthesis in cultures of Streptomyces erythreus estimated by the specific incorporation of 2[14C]-valine into the mycelium changed in accordance with a definite irregular rhythm. When the samples were collected every 6 hours a number of pronounced radioactivity peaks characterizing the intensity of the label incorporation was observed. The height of the peaks was different and they were recorded at different intervals during both the phase of the culture intensive growth and the stationary phase. Erythromycin added to the fermentation medium inhibited protein synthesis at the stationary phase which was evident of the antibiotic effect on the regulatory apparatus controlling the active mycelium growth.

[Action of erythromycin on its own producer in cultivation on broth media]. / Deistvie éritromitsina na sobstvennyi produtsent pri kul'tivirovanii na zhidkikh sredakh.

The effect of erythromycin on the growth, morphogenesis and antibiotic production capacity of the organism producing it or Str. erythreus was studied. Erythromycin was added to the medium in concentrations comparable to the productivity of the organism. It was shown that at the cell level Str. erythreus was highly resistant to its own antibiotic. Still, erythromycin had a significant effect on the developmental cycle of the culture. It inhibited the growth of the mycelium capable of the antibiotic production and induced an increase in reproduction. On long-term subculturing or in the presence of erythromycin the culture showed a pronounced tendency for fragmentation similar to that in proactinomycetes, whereas under the usual conditions the mycelial growth was not disturbed. However, the structure of the septa in Str. erythreus is typical of the streptomycetes. It is concluded that Str. erythreus occupies an intermediate position between Nocardia and Streptomyces.

[Cooperative functioning of 2 systems of protection against its own antibiotic in Str. erythreus 1571, a superproducer of erythromycin]. / Kooperativnoe funktsionirovanie dvukh sistem zashchity ot sobstvennogo antibiotika u Str. erythreus 1571--superprodutsenta eritromitsina.

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.

[Cytomorphological changes in a culture of Streptomyces rimosus, the producer of oxytetracycline, in the presence of different foam retardants]. / Tsitomorfologicheskie izmeneniia kul'tury Streptomyces rimosus--produtsenta oksitetratsiklina--v prisutstvii razlichnykh penogasitelei.

The data on the effect of chemical foam suppressors of various classes on the morphogenesis of 2 strains of Streptomyces rimosus are presented. Correlation between the age of the culture and its reaction to unfavourable conditions is confirmed. During the first 24 hours of the growth the culture is most sensitive to low aeration rates, addition of the foam suppressors, fat deficiency in the medium. Among the foam suppressors used propinol B-400 had the most significant effect on the cells: destruction of the cell coating, marked changes in the morphogenesis and nucleocytosis of the hyphae of the second generation responsible mainly for the antibiotic biosynthesis. A more active strain was more subject to the foam suppressor toxic effect.

[Effect of lincomycin and other protein synthesis inhibitors on the metabolism of Actinomyces roseolus, a producer of lincomycin]. / Vliianie linkomitsina i nekotorykh drugikh ingibitorov belkovogo sinteza na metabolizm Actinomyces roseolus--produtsenta linkomitsina.

The ability of lincomycin, erythromycin and oxytetracycline to affect the synthesis of protein, RNA and DNA in the mycelium of the lincomycin-producing organism Act. roseolus of various ages was studied. The ability of labeled lincomycin to penetrate into the mycelium from the environment was shown and possible presence of the enzymatic systems inactivating lincomycin in the mycelium was studied. Insensitivity of Act. roseolus is due to the protective reactions of the microorganism. One of such reactions involves impermeability of the cell membrane for the antibiotic present in the culture fluid.

[Effect of lincomycin on its own producer, Actinomyces roseolus, during prolonged passage on a liquid culture medium]. / Vliianie linkomitsina na sobstvennyi produtsent Actinomyces roseolus pri dlitel'nom passirovanii na zhidkoi srede.

Act. roseolus rapidly lost its antibiotic activity on passages in liquid media. Degeneration with respect to the antibiotic production property was accompanied by changes in the physiological and morphological characteristics. The culture became low differentiated during the whole developmental cycle. The capacity of the ribosomes for formation of the polysomes and aggregation was decreased or completely lost. The developmental cycle of the culture was shortened because of earlier autolysis and limited formation of the daughter microcolonies. Lincomycin retarded the rate of these changes. The culture preserved its morphological similarity with the initial strain and its viability increased. Therefore, lincomycin promoted some stabilization of the properties of the culture during its passage.

[Effect of lincomycin on its own producer, Actinomyces roseolus, in periodic cultivation in a liquid medium]. / Vliianie linkomitsina na sobstvennyi produtsent Actinomyces roseolus pri periodicheskom kul'tivirovanii na zhidkoi srede.

Lincomycin added to the cultivation medium induced a number of changes in the organism producing it during its ontogenesis when grown recurrently on liquid media. It was found that lincomycin inhibited the culture growth and decreased the absolute amount of the antibiotic synthesized while the specific activity of the culture increased. A number of cytomorphological rearrangements relevant to the adaptive protective reactions was found. It is suggested that an increase in the resistance of the culture to the antibiotic produced by it at the late developmental stages is the result of the above protective reactions.