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T P Efimova

Publications and source records attributed to T P Efimova.

At least 19 recordsLinked to original sources
PubMed1988

[Cytophysiology of Penicillium solitum: a producer of lipase].

The cell population of Penicillin solitum was studied during maximum accumulation of lipase in the medium with electron microscopic and immunofluorescence methods. The data provided a conclusion that 2 types of lypolytic enzymes with various substrate and antigenic characteristics formed in the cells of P. solitum. It is likely that there is a specific inductor for exolipase synthesis as well as relationship endoenzymatic systems.

Fluorescent Antibody Technique↗
PubMed1984

[Action of the products of the vital activity of yeastlike fungi on the biosynthesis of levorin, levoristatin and fatty acids by a Streptomyces levoris culture].

The data on the effect of the products of vital activity of Candida tropicalis, a yeast-like fungus, on the biosynthesis of levorin, levoristatin and fatty acids by Streptomyces levoris are presented. It was shown that the effect of the biostimulators was not specific with respect to production of levorin, since in the presence of the products of vital activity of C. tropicalis an increase in the synthesis of levoristatin and fatty acids was also observed. The qualitative and quantitative composition of the fatty acids of the mycelium of S. levoris was studied. Interrelation between the biosynthesis of levorin and synthesis of unsaturated fatty acids and branched chain fatty acids was noted.

Antifungal Agents↗
PubMed1981

[Interrelationship of polyphosphate metabolism and levorin biosynthesis in Streptomyces levoris].

The effect of inorganic phosphate on biosynthesis of the polyene antibiotic levorin by Streptomyces levoris was studied. At phosphate concentration of 4.0 mM levorin biosynthesis is repressed by 90%, resulting in an increase of ATP and a condensed inorganic polyphosphates content in the producer cells. At phosphate concentration optimal for levorin production (0.04 mM) the level of intracellular ATP sharply falls by the beginning of the steady-state phase of the producer growth and that of polyphosphates decreases 3-6-fold. The inorganic phosphate exerts different effects on polyphosphate metabolism enzymes, such as polyphosphate: D-glucose-6-phosphotransferase, polyphosphate phosphohydrolase, tripolyphosphate phosphohydrolase, pyrophosphate phosphohydrolase, alkaline and acid phosphatase. The strongest effect of phosphate excess is observed in the case of polyphosphate: D-glucose-6-phosphotransferase, whose activity decreases 2-5-fold. The activity of this enzyme was shown to be correlated with the antibiotic accumulation. The data obtained are indicative of interrelationship between the polyphosphate metabolism and levorin biosynthesis.

Adenosine Triphosphate↗
PubMed1980

[Morphological and biochemical characteristics of Streptomyces hygroscopicus mutants induced by streptomycin and hygromycin B].

Under the effect of streptomycin and hygromycin B there were obtained morphological mutants of Str. hygroscopicus differing in their capacity for synthesis of the antibiotic and a complex of proteolytic enzymes, as well as their resistance to high concentrations of the antibiotics. The mutation of resistance to the aminoglycosides with preservation of the initial phenotype did not result in significant changes in biosynthesis of hygromycin B and the enzyme. At the same time the antibiotic resistant mutants with changed morphology of the colonies were characterized by different capacity for the biosynthesis of the enzyme and antibiotic. Mutants with high, productivity of hygrolytin, not producing hygromycin B were most valuable. Production of hygromycin B correlated with the culture capacity to form aerial mycelium and spores. On the contrary, synthesis of hygrolytin by Str. hygroscopicus did not depend on the morphological characteristics of the culture: strains active with respect to hygrolytin synthesis were found among both the mutants forming abundant aerial mycelium and those not forming it. The study on the biochemical characteristics of the cultures showed that by the lipid content and fatty acid composition they belonged to the same group.

Anti-Bacterial Agents↗
PubMed1979

[Action of polyene antibiotics on actinomycetes with a varying lipid makeup].

The effect of polyenic antibiotics, such as nystatin, levorin, amphotericin B and mycoheptin on 93 representatives of various species of the ray fungi was studied. It was shown that resistance of the actinomycetes to the polyens was connected with the absence or insufficient content of sterols (0.001--0.008 per cent in the dry mycelium). On addition of cholesterol to the nutrient media (100 microgram/ml) it was included into the membranes of some cultures and their sensitivity increased 2--60 times. Resistance of Actinomyces sp. LIA 0775 grown on the media with fats differing in their composition decreased 2--4 times. In these cases the culture lipids were characterized by lower content of phospholipids (35--45 per cent from the total lipids as compared to 70--80 per cent when grown on the control medium without fats) and significantly increased content of unsaturated fatty acids (3--4 times).

Actinomycetales↗
PubMed1979

[Effect of inorganic phosphate on levorin biosynthesis and on the mycelial makeup of Streptomyces levoris].

The effect of inorganic phosphate on biosynthesis of the polyenic antibiotic levorin by Streptomyces levoris and composition of the culture mycelium was studied. It was found that the synthetic medium with 0.4 mM of phosphate was optimal for growth of Str. levoris. When the concentration of phosphate was higher, the biomass increased, while the synthesis of levorin appeared to be inhibited and morphological changes in the culture were observed. Phosphate had a significant effect on the mycelium composition. When its concentration was increased 10 times as compared to the optimal one, the amounts of protein, RNA, total phosphorus and polyphosphates increased 1.3--1.4, 1.6--1.7, 2--3 and 10 times respectively, while the synthesis of levorin decreased 5 times. Changes in the lipid component of the mycelium were also observed. In the absence of inorganic phosphate in the medium the acetone precipitating fraction of the lipids contained 20--40 per cent of the phosphoruless compounds. During cultivation their portion increased up to 70--77 per cent. However, in the presence of its excess the polar lipids were represented only by phospholipids during the whole life cycle. The fatty acid spectrum of the lipids did not depend on the phosphate concentration and was represented mainly by saturated fatty acids with a branched chain of a series of iso- and anteiso-structures containing 14--18 carbon atoms.

Antifungal Agents↗
PubMed1977

[Lipid makeup of the initial and selected strains of Actinomyces levoris and Streptoverticillium mycoheptinicum in the process of antibiotic synthesis].

The study of the lipid composition showed that the rate of the changes in the fatty acid composition of neutral lipids and phospholipids in the selected strains was higher than that in the initial strains. The medium composition had the decisive effect on the fractional and fatty acid spectrum of the mycelium lipids. When the antibiotic-producing organisms were grown on the synthetic medium the phospholipids were the predominating fractions (70--90 per cent of the total lipids), while with the use of organic medium they amounted only to 30--40 per cent. The data were evident of complex correlation between the synthesis of fatty acids and polyenic antibiotics, i.e. levorin and mycoheptin.

Anti-Bacterial Agents↗
PubMed1976

[Effect of the physiological activity of Clostridium cells on their sensitivity to antibiotics].

Actively multiplicating cells of C1. perfringens proved to be more sensitive to 7-chlor-7-desoxylincomycin and rifampicin than the cells in the phase of the population dying. The bactericidal effect of the antibiotics on Clostridia vegetating at a temperature range within 37--4degrees was studied. Determination of the content of higher fatty acids in the cultivation medium with the method of gas chromatography showed that the metabolic processes in the bacterial cells went on at a temperature of 4degrees. Sensitivity of Clostridia to antibiotics at 20 and 4degrees lowered. However, all antibiotics inhibited the cell viability under such conditions. The inhibitors of the intracellular protein synthesis, i. e. rifampicin, 7-chlor-7-desoxylincomycin and morphocycline proved to be most active. The effect of beta-lactame antibiotics, i. e. cephaloridine and benzylpenicillin was reliable though lower.

Anti-Bacterial Agents↗
PubMed1975

[Comparative characteristics of some actnomycetes, producers of antifungal antibiotics related to chondamycin].

Three actinomycetous strains designated as LIA-0773, LIA-0783 and LIA-0780 were isolated from various soil samples. The cultures actively inhibited the growth of Trichophyton gipseum and produced a non-polyenic antibiotic of the chondamycin type. The strains were identified with Act. griseochromogenes Fukunaga et. al., 1955. The cultures differed within the species by some morphological, cultural, physiological and antibiotic properties, as well as by the component composition of the antibiotic produced. Thus, strain LIA-0773 had larger spiral sporophores, satisfactorily hydrolized starch and inverted sucrose. The strain inhibited the growth of not only the fungi but also grampositive bacteria and mycobacteria and produced an antibiotic composed of 6 components. Strain LIA-0780 had small sporophores with close spirals and low amilolytic activity. It inhibited only the growth of the fungi and produced a monocomponent antibiotic. Strain LIA-0783 was intermediate. By its biological properties it was closer to strain LIA-0780. The antibiotic produced by it consisted of 6 components, while by its physico-chemical properties the antibiotic was close to that produced by strain LIA-0780. All the 3 actinomycetous cultures were considered as different variants of Act. griseochromogenes Fukunaga et al., 1955.

Actinomycetales↗
PubMedDate not supplied

[Production of protoplasts and membranes in Actinomyces hygroscopus].

Protoplasts of Actinomyces hygroscopicus were obtained in a hypertonic medium containing 10.3% sucrose. Lysozyme was employed as a lysing agent at a concentration of 1 mg/ml. The cells were subjected to lysis during 3-4 hours at 37 degree C, the concentration of biomass being 0.05 g of dry mycelium per 1 ml of hypertonic solution. Production of protoplasts was controlled by phase-contrast microscopy; the amount of the protoplast was determined by optical density at lambda=530 nm. The highest amount of the protoplasts was obtained during growth of the culture on a medium containing 0.5% glycine. The membrane fraction was isolated after lysis of the protoplasts in a hypotonic medium, treatment with DNase and RNase, and centrifugation at 22,000 g in the cold. Production of the membranes was controlled by electron microscopy. The yield of the membranes was 17-19% of the dry mycelium weight. They contained about 35% of lipids, 50% of protein, and 5% of RNA.

Actinomyces↗
PubMedDate not supplied

[Heterogeneity of the genus Actinomadura Lechevalier a. Lechevalier].

Studies of the morphology of Actinomadura spp. have shown that the genus comprises several morphological types of actinomycetes which differ by the presence and structure of the sporophores on the aerial and substrate mycelium. The actinomycetes differ also by the fatty acid composition of lipids in the mycelium, and can be subdivided into three groups: (1) fatty acids with a straight chain prevail; (2) fatty acids with branched chains of the iso- and anteiso structure predominate; and (3) fatty acids with straight and branched chains are contained in almost equal amounts. Therefore the genus separated on the basis of differences in the composition of the cell wall was heterogeneous according to the properties used in the taxonomy of the actinomycetes at the level of genus. These data prove that morphological properties have to be taken into account in the taxonomy of the actinomycetes.

Actinomycetaceae↗
PubMedDate not supplied

[Lipids of Aureobasidium (Pullularia) pullulans].

Fractional composition of free and bound lipids was studied in Aureobasidium (Pullularia) pullulans 8 by preparative TLC on Silufol. Bound lipids contained a fraction (27.76 +/- 0.5%) of dark brown colour, similar to melanin. The composition of fatty acids was studied by GLC. The following fatty acids were identified and determined quantitatively: C12:0, C14:0, C15:0, C16:0, C18:0, C18:1+C15:2. The following fatty acids predominated in free and bound lipids: C16:0, C18:1+C18:2. The ratio between unsaturated and saturated fatty acids in all fractions of free and bound lipids was more than unity. The following parameters were determined for lipids; ester number (173.89 and 178.53); iodine number (44.1 and 33.10), and saponification number (181.17 and 206.03) (the values are given for free and bound lipids, respectively).

Fatty Acids↗
PubMedDate not supplied

[The effect of lipase from Penicillium sp. on the membrane fraction of the levorin-producing Streptomyces levoris].

The effect of a lipase preparation from Penicillium sp. on the membranes of the levorin producer Streptomyces levoris was being studied. The enzyme preparation was found preferably to hydrolyse neutral lipids in the Str. levoris membranes, which makes it possible to use the lipase from Penicillium sp. for studying neutral lipids in microbial membranes.

Antifungal Agents↗
PubMedDate not supplied

[Biosynthesis of the polyene antibiotic levorin and the membrane composition of Streptomyces levoris].

Changes in the composition of Streptomyces levoris membranes were studied in the course of the polyene antibiotic levorin biosynthesis when the process was stimulated by Candida tropicalis metabolites and inhibited by inorganic phosphate. In the presence of stimulating compounds, the percentage of membranes increased in S. levoris cells and the membrane composition changed: the protein-to-lipid ratio and the concentration of total phosphorus decreased while the content of carbohydrates increased. Analysis of the lipid component showed that these changes were due to a gradual substitution of non-phosphorus glycolipids for membrane phospholipids and to an enrichment of the membranes with proteolipids. Such changes were not detected in a medium containing the inhibitor. It was for the first time that a considerable amount of the antibiotic produced by the culture was found in the membrane fractions. The data are discussed in relation with a possible role of the actinomycete membrane structures in levorin biosynthesis.

Antifungal Agents↗