Biomedical subjects

E G Toropova

Publications and source records attributed to E G Toropova.

At least 19 recordsLinked to original sources

PubMed1989

[Effect of metal cations on the formation of antibiotic and pigment by the mycophilic fungus Hypomyces rosellus 94/77].

Using the method of mathematical planning of experiment the effect of calcium, magnesium, manganese, iron, zinc and copper on synthesis of antibiotic and pigment by mycophilic fungus Hypomyces rosellus has been studied. The ions of Mg2+, Mn2+, Fe2+ have been found to be important for antibiotic and pigment formation by fungus, the ions of Mg2+ and Mn2+ are interchangeable.

Anti-Bacterial Agents↗

PubMed1988

[Development of a synthetic medium for the growth of the mycophilous fungus Hypomyces rosellus 94/77 and its synthesis of an antibiotic and a pigment].

Using the method of mathematical design of an experiment the synthetic medium ensuring the growth of the mycophilous fungus Hypomyces rosellus 94/77 and its production of antibiotic and pigment has been worked out.

Anti-Bacterial Agents↗

PubMed1988

[Selection of the seeding media and the age and quantity of mycelia providing simultaneous biosynthesis of an antibiotic and pigment by the fungus Hypomyces rosellus].

The authors observed maximum simultaneous biosynthesis of antibiotic and pigment in the microphilic fungus with using 48-hour seed mycelium having the specific growth rate of 0.008-0.011 h-1 in an amount of 5-7 per cent (v). The Balling 4 degrees wart and Chapek medium with 1 per cent of soybean flower and 1 per cent of corn steep liquor may be used for growing the seed mycelium. No significant effect of the seed medium composition and seed mycelium age on the pigment production was observed.

Anti-Bacterial Agents↗

PubMed1986

[Properties of the extracellular proteases of Hypomyces rosellus].

A protease complex with high caseinolytic activity capable of hydrolysing various protein substrates was isolated from the culture fluid of Hypomyces rosellus. The preparation is stable at pH 6.0-11.0. The temperature optimum of its activity and stability is 50 degrees C. The protease complex preserves its initial activity at 4 degrees C for a month.

Albumins↗

PubMed1986

[Optimizing the composition of the medium for the biosynthesis of antibiotic, proteases and pigments by the mycophilic fungus Hypomyces rosellus using a mathematical experimental design method].

Regulation of protease and pigment production in Hypomyces rosellus by the medium components was easier than that of antibiotic production. Medium was developed. The activity of exoproteases and pigment with the use of this medium increased up to 385-800 PU/ml and 0.68-0.83 arbitrary units, respectively. The level of the antibiotic biosynthesis was insignificant.

Anti-Bacterial Agents↗

PubMed1976

[Study of the carbohydrate metabolic enzyme activity of Act. noursei].

Activity of aldolase and threosophosphate dehydrogenase, transketolase and phosphogluconate dehydrogenase in Act. noursei, strain 153 and its inactive mutant 149 was studied comparatively. The enzyme activity of the inactive mutant was investigated in the absence of the antibiotic production and under conditions of reduced biosynthesis of nystatin in this strain after addition of the fermentation broth filtrate of the inactive mutant 369 to the medium. The activity of the enzymes of the hexosomonophosphate metabolic pathway in the active strain 153 of Act. noursei was 2-4 times higher than that of the inactive mutant 149. The activity of the enzymes of the hexosomonophosphate metabolic pathways increased and reached the level of the enzyme of the active mutant. The high level of the enzyme activity of the hexosomonophosphate glycolysis pathway is probably one of the necessary conditions for nystatin production.

Carbohydrate Metabolism↗

PubMed1976

[Nystatin biosynthesis by inactive mutants of Act. noursei when cultured together].

Inactive mutants of the nystatin-producing organism Act. noursei were selected. When 2 of them were cultivated together, nystatin biosynthesis was restored. The substance or substances restoring the antibiotic biosynthesis was excreted into the culture broth. It had non-protein nature and was stable on storage. Reduction of the nystatin biosynthetic chain proceeded without changes in the cultivation conditions.

Culture Media↗

PubMed1975

[Study of the fructosediphosphate aldolase and transketolase activity in the nystatin producer, Actinomyces noursei].

Activity of transketolase, an enzyme of the pentose cycle and fructosodiphosphataldolase, an enzyme of glycolisis was studied in the dynamics of development of the nystatin-producing organism and its inactive mutant under various conditions of their cultivation with a purpose of finding relation between the antibiotic production and general metabolism of Act. noursei. The transketolase activity of the organism was 2-4 times higher than that of the inactive mutant. Addition of 8000 Units/ml of nystatin to the medium markedly suppressed (50-100 per cent) the aldolase activity, however it had no effect on the transkelotase activity. Possibly the antibiotic accumulated in the mycelium played the role of a regulator of the activity of the enzymes, directing the metabolites along the hexosomonophosphate pathway of carbohydrate dissimilation.

Aerobiosis↗

PubMed1974