[Dynamics of antibiotic biosynthesis by Streptomyces chrysomallus with different plasmid status in submerged and surface culture]. / Issledovanie dinamiki biosinteza antibiotikov shtammami Streptomyces chrysomallus s razlichnym plazmidnym statusom v pogruzennoi i poverkhnostnoi kul'ture.

The dynamics of simultaneous production of two antibiotic substances of different structure by the same species streptomycete was studied. The comparative investigation of accumulation of actinomycin C (AC) and macrotetrolides (MTL) was performed in aerated submerged culture and on surface culture with three strains of Streptomyces chrysomallus of different plasmid status and with their bld mutants. It was shown that the dynamics of the AC and MTL production was different in the liquid medium and on the agarized medium. The maxima of the AC and MTL production were observed at different stages of the S.chrysomallus development which was likely due to different physiological roles of the two antibiotics in S.chrysomallus. The character of the MTL accumulation in the culture of bld mutants differed from that of the starting strains. By the level and dynamics of the antibiotics biosynthesis S.chrysomallus BKM Ac-590 and its mutants containing plasmids pSCH2 and pSCH3 differed from the other strains.

[Biosynthesis of nactinic compounds by population variants of macrotetrolide-producing streptomycetes]. / Biosintez naktinovykh soedinenii populiatsionnymi variantami streptomitsetov--produtsentov makrotetrolidov.

Strains of Streptomyces chrysomallus subsp. macrotetrolidi and soil isolates of Streptomyces spp. producing ammonium specific agents were studied and correlation between the synthesis of nactinic acids and their oligomers and the hydrophobic nature of the active variant in the streptomycete population was shown.

[Plasmids from certain strains of Streptomyces chrysomallus]. / Plazmidy nekotorykh shtammov Streptomyces chrysomallus.

Plasmid content has been studied in a number of Streptomyces chrysomallus strains producers of actinomycin C. The plasmids pSCH2 and pSCH3 have been isolated from nocardia-like mutants of Streptococcus chrysomallus BKM Ac-590 that are producing antibiotics macrotetrolides, bacteriocins and an inducer analogous to A-factor in addition to actinomycin. The size of the plasmids is 13.4 and 15.1 kb as found by restriction analysis. Plasmids differ in deletion and content in the cultures. The ability of the strains to produce antibiotics depends on plasmid content.

[Biologically active substances formed by a number of strains of the actinomycin C producer--Streptomyces chrysomallus]. / Biologicheski aktivnye veshchestva, obrazuemye riadom shtammov produtsenta aktinomitsina C--Streptomyces chrysomallus.

Biologically active substances produced by some strains of S. chrysomallus and their mutants with different levels of the differentiation were studied. Along with actinomycin C the strains produced macrotetrolides, bacteriocins and A factor-like substances. It was shown that the plasmid status of the strains was different. This suggested that the plasmid presence was a characteristic of the strains and the production of the studied substances was likely typical of S. chrysomallus.

[Stability of Escherichia coli to the membranotropic antibiotic gramicidin S]. / Izuchenie ustoichivosti Escherichia coli k membranotropnomu antibiotiku gramitsidinu S.

The work was aimed at studying the effect of gramicidin S on the intact cells, spheroplasts and membrane specimens of Escherichia coli K12S with the natural resistance to this antibiotic. The resistance was shown to be caused by the barrier properties of the cell wall: the spheroplasts were highly sensitive to the lytic action of gramicidin S. The differences in the sensitivity to gramicidin S of substrate oxidation carried by the membranes of E. coli and Micrococcus luteus, a sensitive organism, were not of crucial significance for the manifestation of the resistance. The resistance was not associated with the decrease of gramicidin S adsorption: the cells were capable of binding large quantities of the antibiotic and remaining viable. Gramicidin S appeared to be attached to the cell walls (most likely, the outer membranes) rather than the cytoplasmic membranes.

[Action of thomicide on bacterial cells. The membranotropic activity of thomicide]. / Izuchenie deistviia tomitsida na bakterial'nye kletki. Membranotropnaia aktivnost' tomitsida.

It was shown that a combined drug thomicide impaired permeability of cell membranes in Micrococcus luteus 2665 and Staphylococcus aureus 209P inducing production of substances with the absorption maxima at 260 nm. Active lysis of the M. luteus 2665 protoplasts under the action of thomicide used in a dose of at least 60 micrograms per 1 mg of the protoplast proteins was observed. Thomicide inhibited oxidation of the substrates by intact cells of the staphylococci and micrococci. Respiration of the micrococcal protoplasts was inhibited by thomicide in concentrations inducing lysis of the protoplasts. Impairment of function and the state of the membranes of the bacterial cells (production of compounds with the absorption maxima at 260 nm, protoplast lysis and respiration inhibition) was recorded at thomicide concentrations lower than the bactericidal ones. The membranotropic activity of thomicide was associated with thermostable component of the complex.

[Effect of palmitate on energy coupling in lymphocyte mitochondria]. / Vliianie pal'mitata na énergeticheskoe sopriazhenie mitokhondrii limfotsitov.

In the presence of 0.1 micrograms/ml of oligomycin, DNP (40-60 microM) increases lymphocyte respiration 10-fold and more. Palmitate taken at the same concentration stimulates the respiration of isolated mitochondria (1-2 mg prot/ml) in the presence of 1 mg/ml of BSA and the respiration of lymphocytes (10(8) cells/ml). When BSA and EGTA are absent in mitochondria isolation media, the mitochondrial respiration does not increase after DNP or ADP addition. Lymphocyte preparations are mostly distinguished by mitochondrial morphology in the presence of the uncoupler; they differ less by changes in dis-C3-(5) fluorescence after addition of 5-10 microM DNP and only insignificantly by the stimulation of respiration by DNP and palmitate. These results may be explained by the increase in the uncoupler-induced permeability of mitochondria for K+ and by partial transformation of delta psi m into delta pH in some cells, which may increase the cell resistance to damaging influences.

Mitochondrial membrane potential in lymphocytes as monitored by fluorescent cation diS-C3-(5).

A lipophilic fluorescent cation diS-C3-(5) and rotenone suppress the oxygen consumption rate of thymocytes in similar concentrations. Seventy percent inhibition corresponds to an inhibitor:cytochrome a molar ratio of about 1:1. Addition of uncouplers decreases the inhibition of respiration by diS-C3-(5) (but not rotenone). FCCP in similar concentrations increases O2 consumption in the absence of diS-C3-(5) and the diS-C3-(5) fluorescence intensity in the presence of TMPD in thymocyte suspensions. In most thymocyte preparations, oligomycin (0.05-0.1 microgram/mL) increases the fluorescence of diS-C3-(5) and further addition of TMPD (50-100 microM) decreases the fluorescence. Addition of NaCN (400 microM) after oligomycin leads to a fluorescence increase that is hardly affected by subsequent addition of 0.2 microM FCCP. Nigericin (10-50 nM) decreases the diS-C3-(5) fluorescence. The data indicate that the diS-C3-(5) fluorescence associated with mitochondrial transmembrane potential (delta psi m) may be an essential part of the diS-C3-(5) fluorescence in lymphocyte suspensions. The changes of the diS-C3-(5) fluorescence intensity in the presence of TMPD after FCCP addition reflect delta psi m.

[Interaction of diS-C3-(5) and ethylrhodamine with lymphocyte mitochondria]. / Vzaimodeistvie diS-C3-(5) i étilrodamina s mitokhondriiami limfotsitov.

The interaction of thymocyte mitochondria with two types of dyes - potential indicators commonly used in lymphocyte studies, has been investigated. Ethylrhodamine at concentrations up to 16 microM does not influence the systems of oxidation and energy coupling in lymphocyte mitochondria. Carbocyanines-diS-C3-(5) and diO-C3-(5) inhibit oxygen uptake by the lymphocytes in the presence of glucose and pyruvate at the same low concentrations as does rotenone (40% inhibition occurs at 10 nM). DNP reduces the inhibition of respiration by carbocyanines but not by rotenone. The increase in the fluorescence of diS-C3-(5) and in the rate of oxygen uptake in the absence of diS-C3-(5) occurs at close concentrations of the uncoupler. This indicates that the changes in the fluorescence caused by FCCP reflect the membrane potential of lymphocyte mitochondria. The maintenance of the membrane potential in lymphocyte mitochondria in the presence of diS-C3-(5) provides evidence for the absence of the corresponding changes in mitochondrial ultrastructure after addition of 0.6 microM diS-C3-(5) which completely inhibits oxygen uptake.

[Effect of heliomycin on the respiration and oxidative phosphorylation of the liver mitochondria of the rat]. / Vliianie geliomitsina na dykhanie i okislitel'noe fosforilirovanie mitokhondrii pecheni krysy.

The effect of heliomycin and known uncouplers of oxidative phosphorylation on respiration and oxidative phosphorylation was studied comparatively. Heliomycin, as well as 2,4-dinitrophenol, valinomycin and gramicidin S inhibited the mitochondrial synthesis of ATP. This process was inhibited completely by heliomycin at a concentration of 1.5 x 10(-5) M. The synthesis of inorganic pyrophosphate, the other macroergic compound, was also inhibited by heliomycin, ATPase and pyrophosphatase of uncoupled mitochondria being not inhibited by the antibiotic. Like 2,4-dinitrophenol, heliomycin stimulated the synthesis of ATPase and respiration in intact mitochondria. Probably, heliomycin inhibited the synthesis of ATP and pyrophosphate by uncoupling the processes of respiration and oxidative phosphorylation. It was shown earlier that heliomycin, a specific inhibitor of bacterial RNA synthesis, also affected energy metabolism of bacterial cells by inhibiting the synthesis of ATP and active transport.

[Effect of carbonyl-conjugated pentaene-group antibiotics on the oxygen absorption rate of a thymocyte suspension]. / Vliianie antibiotikov gruppy karbonil-kon"iugirovannykh pentaenov na skorost' pogloshcheniia kisloroda suspenziei timotsitov.

When used in concentrations of 10-15 micrograms per 10(8) cells, flavofungin and nigrofungin, carbonyl-conjugated pentaenes lowered the rate of oxygen absorption by thymocyte suspensions in the presence of glucose. Flavopentin inhibited glucose oxidation in higher concentrations. ADP and succinate did not penetrate through the thymocyte membranes and were not oxidized with the cell suspensions. In concentrations of 30 micrograms per 10(8) cells the pentaenes did not change the membrane permeability for ADP. Still, they induced oxidation of succinate by the thymocytes (in the presence of amital). Flavofungin and nigrofungin were more effective with respect to increasing the membrane permeability for succinate as compared to flavopentin. The differences in the membrane permeability for various substrates induced by the antibiotics indicated a definite specific nature of the impairment of the thymocyte cytoplasmic membranes by carbonyl-conjugated pentaenes. The antibiotics tested are very similar as to their chemical structure and physicochemical properties. It is suggested that the differences in the biological activity of these substances are not associated with the presence of definite functional groups but are due to the general configuration of the antibiotic molecules, determining their hydrophilic-lipophilic balance and capacity for interaction with the biological membranes.

[Phosphohydrolases of the phytopathogenic fungus Phytophthora infestans (Mont) de Bary]. / Fosfogidrolazy fitopatogennogo griba Phytophthora infestans (Mont) de Bary.

ATPase, pyrophosphatase and tripolyhosphatase activities were found in a cell-free Phytophtora infestans micelium extract. No polyphosphatase activity, hydrolyzing high molecular weigh polyphosphates to orthophosphate, was observed in the fungi. It was demonstrated that, unlike ATPase, the activity of pyrophosphatase was inhibited by Ca2+ at concentrations from 0.1 to 20 mM, and it was considerably decreased in the presence of a Ca2+ transport inhibitor, ruthenium red (0.01--0.1 mM). Possible relation of Ph. infestans pyrophosphatase activity with the process of active calcium transport is suggested.

[Inorganic polyphosphate metabolism in Staphylococcus aureus and the action on it of antibiotics]. / Obmen neorganicheskikh polifosfatov u Staphylococcus aureus i deistvie na ego nekotorykh antibiotikov.

The culure of Staph. aureus in the exponential growth phase contained 14-18 mg/g of dry orthophosphate biomass and 18-22 mg/g of dry acid insoluble polyphosphate biomass. The extracellular extract of the culture had a phosphohydrolase activity with respect to high molecular polyphosphates, tripolyphosphate and pyrophosphate. Penicillin and bacitracin which inhibited the biosynthesis of the cell wall had no effect on the content of polyphosphates and the phosphohydrolase activity of Staph. aureus. Heliomycin which inhibited the biosynthesis of RNA increased the content of polyphosphates by 1.5 times and decreased the content of ATP by 30 per cent in the cells of Staph. aureus.