Resistance to the polyether ionophore antibiotic pandavir (nigericin) in two producing strains of Streptomyces.

In two pandavir (nigericin) producing strains, Streptomyces hygroscopicus 155 and Streptomyces albogriseolus 444, an enzyme activity was detected leading to inactivation of the antibiotic in the presence of ATP-Na2. Apparently, the observed inactivation is specific for the antibiotic produced by these strains. The nigericin producing strains were also found to be less permeable to pandavir than their non-producing variants.

[Calcium ions and the differentiation of Streptomyces hygroscopicus 155, a producer of an antibiotic complex]. / Iony kal'tsiia i differentsiatsiia Streptomyces hygroscopicus 155, produtsenta antibioticheskogo kompleksa.

The effect of Ca2+ on differentiation of Streptomyces hygroscopicus 155 and its inactive variant 155-0 was studied. Addition of Ca2+ to the medium induced formation of the aerial mycelium in the inactive variant and accelerated formation of the aerial mycelium in the parent strain. The inhibitory effect of EGTA, verapamil, nifedipin, chlorpromazine and dilthiazeme on the aerial mycelium formation demonstrated the physiological role of Ca2+ in the process. Addition of pandavir (nigericin) and azalomycin B, the antibiotics produced by the streptomycete, induced formation of the aerial mycelium in the inactive variant. The effect was higher in the presence of Ca2+. Streptomyces hygroscopicus 155 and its inactive variant synthesized a proteolytic complex containing metalloproteases and trypsin-like proteases. The total proteolytic activity of the inactive variant was lower than that of the parent strain. Addition of Ca2+ to the medium stimulated their proteolytic activity. The inducing action of the antibiotics produced by the parent strain on differentiation of S.hygroscopicus 155-0 and the increase of their action in the presence of Ca2+ suggested that they controlled the differentiation and that such a function of the antibiotics expressed itself through the Ca2+ signal system.

[Resistance of the strain Streptomyces hygroscopicus 155 to autogenous and other antibiotics]. / Ustoichivost' shtamma Streptomyces hygroscopicus 155 k sobstvennym i k drugim antibiotikam.

Streptomyces hygroscopicus 155, a strain producing pandavir (nigericin) and azalomycin, was studied with respect to resistance to its own and some other antibiotics i.e. tetracycline, gentamicin, streptomycin, erythromycin, tylosin, thiostreptone, benzylpenicillin, monensin and salinomycin. An inactive variant of the culture was used in the control.

[Effect of protoplasting on antibiotic activity and resistance in the strain Streptomyces hygroscopicus 155]. / Izuchenie vliianiia protoplastirovaniia na antibioticheskuiu aktivnost' i antibiotikorezistentnost' shtamma Streptomyces hygroscopicus 155.

The influence of protoplasting and protoplast regeneration in the presence of polyethylene glycol on antibiotic activity, components of antibiotic complexes and antibiotic resistance in Streptomyces hygroscopicus 155 was studied. It was shown that the protoplasting and protoplast regeneration influenced the antibiotic activity. The protoplast fusion resulted in increased isolation of variants with higher antibiotic activity. The processes also affected the components of the antibiotic complexes but had no effect on the strain resistance to some antibiotics.

[Effect of calcium ions on the differentiation of actinomycetes]. / Vliianie ionov kal'tsiia na differentsiatsiiu aktinomitsetov.

The influence of Ca2+ on the formation of the aerial mycelium in 23 actinomycete strains was studied. It was shown that in concentrations up to 5 mM exogenous Ca2+ induced the formation of the aerial mycelium in 11 out of the 23 actinomycete strains tested. The Ca2+ channel blockers (verapamil and nifedipine), calmodulin inhibitor (chlorpromazine) and Ca2+ chelator (EGTA) inhibited the aerial mycelium formation in 3 streptomycete strains out of the 23 actinomycetes. Chlorpromazine and nifedipine proved to be the most active inhibitors when used in concentrations of 0.2 to 2.5 mumol/disk. The Ca2+ concentrations of 5 mM were found to stimulate the formation of the submerged spores in S. hygroscopicus 155. The activity of ATP synthase was stimulated in the aerial and submerged spores after the Ca2+ uptake.

[Calcium ions in the life cycle of Streptomyces albogriseolus 444]. / Iony kal'tsiia v zhiznennom tsikle Streptomyces albogriseolus 444.

The influence of Ca2+ on the growth, antibiotic production and differentiation of Streptomyces albogriseolus 444 was studied. Consumption of the calcium ions by the strain was followed up. It was shown that Ca2+ changed the dynamics of the biomass accumulation and had no significant effect on the antibiotic production. Calcium present in the medium was assimilated more intensively during the first 24 hours of the strain growth. The own antibiotic nigericin exogenously added to the medium increased the calcium assimilation. In the presence of Ca2+ the nigericin stimulation of the strain differentiation was higher.

[Resistance to its own antibiotic nigericin and macromolecular synthesis in Streptomyces hygroscopicus 155]. / Rezistentnost' k sobstvennomu antibiotiku nigeritsinu i makromolekuliarnyi sintez u Streptomyces hygroscopicus 155.

The influence of nigericin (nandavir) on the organism producing it (Streptomyces hygroscopicus 155) was studied with respect to the synthesis of protein, RNA and DNA. The resistance of the mycelium of different ages to the exogenic antibiotic was investigated. Exogenic nigericin had a more marked inhibitory effect on the macromolecular synthesis in a nonproductive variant of the strain. The antibiotic sensitivity of the mycelium in both the variants (productive and nonproductive) depended on the culture age. It was suggested that there were not less than two mechanisms of the protection from the own antibiotic in the organism.

[Isolation and partial characterization of NAD+ kinase from Streptomyces albogriseolus 444]. / Vydelenie i chastichnaya kharakteristika NAD+ kinazy Streptomyces albogriseolus 444

NAD+ kinase was isolated from the culture of Streptomyces albogriseolus 444. an organism producing an antibiotic complex. The enzyme was partially characterized. Its molecular weight is 141219 Da.

[Physiological role of extracellular proteases and calcium ions in the processes of differentiation and antibiotic production by Streptomyces albogriseolus 444]. / Fiziologicheskaia rol' vnekletochnykh proteaz i ionov kal'tsiia v protsessakh differentsiatsii i antibiotikoobrazovaniia Streptomyces albogriseolus 444.

The extracellular proteolytic activity of Streptomyces albogriseolus 444 was investigated. S. albogriseolus 444 was shown to synthesize an extracellular proteolytic complex with metal-protease and trypsin-like activity defining differentiation of the substrate mycelium to the aerial one as well as the spore formation. The synthesis of the complex proceeded in the absence of the inductor in the medium i.e. constitutively. The complex heterogeneity was confirmed chromatographically. Low concentration of calcium ions (1.5 mM) stimulated the total caseinolytic activity and suppressed the activity of the trypsin-like proteases.