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V V Zhirova

Publications and source records attributed to V V Zhirova.

2 recordsLinked to original sources

[Effect of carbon composition of the fermented medium on the synthesis of volatile acids by the yeast Saccharomyces carlsbergensis 776].

The effect of glucose, maltose and sucrose on the synthesis of volatile oils during fermentation of model carbohydrate solutions (6, 8 and 11%) by the yeast Saccharomyces carlsbergensis 776 was studied. The composition and concentration of carbohydrates affected the build-up of volatile fatty acids during fermentation. The accumulation of biomass and volatile fraction of fatty acids reached maximum on the medium containing 11% glucose. There was a certain correlation between the biomass synthesis and accumulation of volatile fatty acids, i.e. with an increase in the biomass the content of volatile fatty acids in the medium increased. During fermentation of disaccharide solutions cell multiplication diminished and the fermentation process accelerated. Ethanol, residual sugar and acidity of fermented solutions increased with the initial concentration of carbohydrates. The pH value of the fermented must remained essentially unaltered independent of the sugar amount used.

Culture Media

[Effect of microelements on formation of acids and ethyl alcohol by Saccharomyces carlsbergensis yeasts].

The effect of Fe, Zn, Mn, Pb, Al, Cu, and K on the synthesis of pyruvic, alpha-ketoglutaric and total volatile acids and ethanol was studied in the process of fermentation of 6 per cent maltose solution by Saccharomyces carlsbergensis 776. Experiments were conducted using techniques of their mathematical planning. Fe, Pb, and Mn at concentrations of 15.0, 0.5, and 1.5 mg/litre, respectively, had a positive effect on the synthesis of pyruvic acid whose concentration in the medium increased by 3.3 mg per 100 ml to become equal to 43.3 mg per 100 ml. Fe3+ at a concentration of 15 mg/litre had a negative effect on the synthesis of alpha-ketoglutaric acid. The synthesis of volatile acids depended on the presence of Fe, Zn, Pb, Al, and K. Fe and Al at concentrations of 15 mg/litre favoured the synthesis of volatile acids by 2.72 mg/litre. In the presence of Zn (1.5 mg/litre), Pb (0.5 mg/litre), and K (15 mg/litre), the content of volatile acids decreased by 4.48 mg/litre and became equal to 14.94 mg/litre. Zn at a concentration of 1.5 mg/litre inhibited it.

Acids