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Biomedical subjects

V K Eroshin

Publications and source records attributed to V K Eroshin.

At least 19 recordsLinked to original sources
PubMed2000

Application of mass and energy balance regularities in fermentation. Reprinted from Biotechnology and Bioengineering, Vol. XX, No. 10, Pages 1595-1621 (1978).

Material and energy balances for fermentation processes are developed based on the facts that the heat of reaction per electron transferred to oxygen for a wide variety of organic molecules, the number of available electrons per carbon atom in biomass, and the weight fraction carbon in biomass are relatively constant. Mass-energy balance equations are developed which relate the biomass energetic yield coefficient to sets of variables which may be determined experimentally. Organic substrate consumption, biomass production, oxygen consumption, carbon dioxide production, heat evolution, and nitrogen consumption are considered as measured variables. Application of the balances using direct and indirect methods of yield coefficient estimation is illustrated using experimental results from the literature. Product formation is included in the balance equations and the effect of product formation on biomass yield estimates is examined. Application of mass-energy balances in the optimal operation of continuous single-cell protein production facilities is examined, and the variation of optimal operating conditions with changes in yield are illustrated for methanol as organic substrate.

Electrons↗
PubMed1984

[Microorganisms as potential producers of essential fatty acids].

The data on the importance of essential fatty acids in a balanced diet have been considered. The ways of essential fatty acid synthesis in microorganisms and their metabolism in animal tissues are being discussed. The criteria for microorganisms selection--producers of food lipids have been proposed.

Animal Nutritional Physiological Phenomena↗
PubMed1982

[Effect of the growth rate on the biomass composition of Candida valida].

The effect of growth rate on the biomass composition was studied with a thermotolerant strain of the yeast Candida valida grown in the chemostat at limitation of the growth by ethanol under the conditions of various temperature regimes. The temperature and the growth rate hardly influenced the content of protein and its amino acid composition. An increase in the specific growth rate of the cells caused a rise in the pool of free intracellular amino acids, in particular, glutamic acid. The degree of lipid unsaturation increased with a rise in the growth rate of the yeast as a result of intensification of oleic acid oxidative dehydration. As it had been shown earlier, the content of nucleic acids increased with a rise in the specific growth rate of the yeast.

Amino Acids↗
PubMed1977

Dependence of cell yield and specific growth rate of Candida boidinii on temperature during continuous cultivation.

Investigation of the dependence of cell yield of Candida boidinii in a chemostat and specific growth rate in a turbidostat on temperature was carried out using methanol as substrate. Each of the curves obtained had only one maximum, the optimum temperature for yield (Ys) and for specific growth rate (micron) being somewhat different. With deviation of temperature from the corresponding optimum the micron value decreases more sharply than that of Ys. The shape of two-factor dependences Ys(micron, T) and micron(S, T) is analyzed on the basis of these data and the known dependences of Ys on micron and micron on the limiting substrate concentration S. It is shown that the decelerating action of methanol on the growth rate increases at elevated and lower temperatures.

Candida↗
PubMedDate not supplied

[Effect of conditions od Trichosporon pullulans culturing on the synthesis of immunomodulating glycoprotein].

An extracellular glycoprotein (GP) exhibiting immunomodulating activity produced by the yeast Trichosporon pullulans grown in a defined ethanol-containing medium differed substantially in its composition from that of the yeast cell walls: therefore, it cannot be considered a structural component of the cell walls. In batch culture, the greatest GP production (40 mg/l) occurred in the exponential phase of the yeast growth. Under continuous cultivation, in both chemostat and pH-auxostat regimes, the specific rate of GP synthesis (qGP) increased with the increasing specific growth rate (mu) and reached 1.55 mg/(g h) at mumax. Under limitation of the yeast growth by zinc qGP was three times lower than under nitrogen or iron limitation. The rate of GP production depended inversely on the oxygen concentration.

Adjuvants, Immunologic↗
PubMedDate not supplied

[Quantitative analysis of polypeptides by disc electrophoresis in pore gradients].

The quantitation of components in a complex mixture of proteins of Pseudomonas denitrificans separated by disc-electrophoresis in the linear pore gradient of polyacrylamide gel was studied. The problem of a poor staining of proteins in the presence of a detergent was solved by a high resolving power photography. A linear correlation between the amount of protein in the fraction and the intensity of amide black staining was extablished. In comparison to the wild type of P. denitrificans the aldehyde negative mutant showed significant changes in protein fractions amounting to 30% of total protein, according to the densitometrical data. It is suggested that the changes are related to the protein migration in fractions rather than to an additional synthesis in different protein fractions.

Bacterial Proteins↗
PubMedDate not supplied

[Changes in the composition of intracellular lipids and hydrocarbons in Candida tropicalis in the absence of growth].

The fatty acid composition of lipids and the composition of hydrocarbons were studied in Candida tropicalis cultivated on a medium with propionic acid and incubated in the conditions of starvation and on a medium containing glucose-1-6-14C but no nitrogen. Intracellular fatty acids with an odd number of carbon atoms were found to be easily metabolized by yeast cells. The content and composition of intracellular hydrocarbons were very labile and underwent intensive transformation caused by changes in the metabolism of the yeast cell.

Candida↗
PubMedDate not supplied

[Yeasts utilizing methyl alcohol].

The ability to utilize methanol was found in the yeast strains isolated from forest substrates (Zygowillia pini IBFM y-655, Torulopsis molicshiana IBFM y-657) and in the collection yeast cultures (Candida boidinii IBFM y-588 and IBFM )-587). These yeasts assimilated not only methanol but other alcohols (ethanol, glycerol, erythrol, mannitol, and sorbitol), nitrates or nitrites. Their fermentation ability was low.

Candida↗
PubMedDate not supplied

[Inhibition of Candida valida growth by copper ions].

The high toxicity of copper ions for Candida valida growth was established at pH-auxostat regime. The value of mu max decreased even at the residual Cu2+ concentration 1.0 mg/l. The inhibition constant (Ki) that characterized a copper ion concentration at which yeast specific growth rate was halved was equal to 7.7 mg/l. A linear dependence of 1/mu max on a residual concentration of copper ions indicates that yeast growth inhibition is due to inhibition of one enzymic reaction which is the most sensitive to copper. Yeast growth inhibition by copper was accompanied by accumulation of Cu2+ ions in biomass, a decrease in nucleic acid and true protein contents, and changes in amino acid composition of protein. The amounts of cystine and cysteine in protein increased and tryptophane content decreased with inhibition of yeast growth. Yeast growth inhibition by copper did not affect the lipid content but significantly reduced the degree of unsaturation due to a decrease in the amounts of polyunsaturated linoleic and alpha-linolenic acids.

Candida↗
PubMedDate not supplied

[Effect of cell metabolism on the rate of medium addition during pH stabilized cultivation].

The rate of base or acid addition to the culture broth for maintenance of the present pH-value is a quantity reflecting the metabolic activity of the cell population. This quantity is proportional to the biomass growth rate with the proportionality coefficient depending on the cell consumption of ionized substrates from the environment, cell biomass, electric charge, and content of ionized metabolic products in the medium. The equation for this relationship has been found and the effect of the above, factors on the titration rate has been calculated. This rate may be used to obtain rapidly the quantitative information on the growth of the cell population.

Bacteria↗
PubMedDate not supplied

[Alkane-induced protein biosynthesis in Pseudomonas aeruginosa].

Protein disc-electrophoregrams of cell-free homogenates have been compared in the "non-adapted" and "preliminarily-adapted" to n-hexane strains of Pseudomonas aeruginosa. A statistically reliable increase in the content of protein by 60 per cent was found in fractions a (M. W. 70,000) and b (M. W. 130,000) when the cells of both strains were gorwn on hexane as compared to the cells cultivated on glucose. The content of protein in each a and b band was about 4 per cent of the total cell protein before the induction by hexane. No differences were found when the cells of the two strains were grown on identical substrates. The induced proteins are supposed to belong to the system of primary oxidation of n-alkanes with short chains and to be localized in the cytoplasm of Ps. aeruginosa.

Alkanes↗