[Optimization of the process of culturing yeast in the presence of the dispersed mineral palygorskite]. / Optimizatsiia protsessa kul'tivirovaniia drozhzhei v prisutstvii dispersnogo minerala palygorskita.

A positive effect from introduction of the highly dispersed mineral palygorskite in the nutrient medium for aerobic batch cultivation of the yeast Saccharomyces cerevisiae, the Kyivsky strain, used in production of champagne has been established experimentally. An adequate mathematical model describing the process of growth has been constructed. Optimal cultivation conditions have been determined which provided for the achievement of such yeast cell concentration in the culture fluid as 116 mln/ml, palygorskite concentration in the nutrient medium being 0.37 g/l and sucrose 2.0 +/- 0.2%. The yeast obtained possess higher fermentation activity.

[Certain features of culturing Saccharomyces cerevisiae (Kiev strain) in a wine medium]. / Nekotorye osobennosti kul'tirovaniia Saccharomyces cerevisiae (shtamm kievskii) na vinnoi srede.

The growth of yeast Saccharomyces cerevisiae Kyivsky strain, used in production of champagne, has been studied as affected by a number of factors. The optimum values of saccharose concentration and partial pressure of oxygen dissolved in the medium under which the carbohydrate source use efficiency achieved 9 mln cells/mg of saccharose have been established. The strain growth on the nutrient medium with 2% of saccharose traditionally used in the champagne production has been investigated under the conditions of periodic cultivation. It has been shown that at the beginning of cultivation the low values of the economic coefficient were determined by the Crabtree effect. The saccharose concentration in the culture liquid being decreased to 1%, the carbohydrate utilization efficiency decreases considerably. A chemostatic method of the strain cultivation under growth limitation has been proposed to achieve high concentrations of yeast. Under periodical cultivation the saccharose concentration in the culture liquid would be supported at the level of 0.5-1.0% by its fractional introduction to the fermenter.

[The growth characteristics of the yeast Saccharomyces cerevisiae on media containing ethanol and saccharose]. / Osobennosti rosta drozhzhei Saccharomyces cerevisiae na sredakh, soderzhashchikh étanol i sakharozu.

Joint effect of various concentrations of alcohol and saccharose in the medium as well as the influence of temperature are studied under conditions of batch cultivation of Saccharomyces cerevisiae. It has been found that saccharose added to the medium in the amount exceeding 1% is assimilated less efficiently. So, it is not expedient to exceed the above concentration in industrial nutrient media with 10-12 vol. % of ethanol. The biomass yield within 18-22 degrees C depends only on the alcohol amount in the medium. A further rise in temperature to 35 degrees C induces its inhibitory effect ever growing with the ethanol concentration in the medium. Mathematical modeling shows basic regularities of the growth process which permit predicting behaviour of the culture in the studied factorial space. Optimal values of saccharose concentrations and cultivation temperature for the most efficient cultivation of yeast on the ethanol-containing medium are determined.

[The growth characteristics of Enterococcus faecium under batch cultivation conditions]. / Osobennosti rosta Enterococcus faecium v usloviiakh periodicheskogo kul'tivirovaniia.

Growth peculiarities of the strain of homoenzymic lactic acid bacteria Enterococcus faecium under periodic cultivation have been studied. The effect of carbohydrates source on the level of biomass accumulation and efficiency of its use by the strain is shown. Glucose concentration in the medium being increased from 1.0 to 3.5%, the economic effect decreases from 16.0 to 10.6%. It is established that only at the beginning of cultivation the specific growth rate of the strain is determined by the concentration of lactic acid. This dependence can be described by Ierusalimsky's equation. The obtained values of micronm and Kp are 1.5 h(-1) and 6.5 g/l, respectively. Biomass concentration being above 0.3 g ACB/l, the strain growth depends on two factors: inhibition of lactic acid and limitation of the sources of nitrogen nutrition. Interaction of these two factors results in considerable decrease of specific rate of bacterial growth.

[Characteristics of growth and changes in the ultrafine structure of bacteria in the course of continuous cultivation on media containing ethanol]. / Nekotorye zakonomernosti rosta i izmeneniia ul'tratonkoi struktury bakterii pri nepreryvnom kul'tivirovanii na sredakh s etanolom.

A large number of bacterial strains assimilating chemical ethanol has been isolated using an original technique. Active growth of strains belonging to the genera Pseudomonas and, particularly, Acinetobacter was registered on mineral media containing ethanol. A mathematical model was constructed select a strain of Acinetobacter calcoaceticus K-9 during its continuous cultivation on media containing ethanol. The model makes it possible to determine conditions for producing a present amount of the biomass, the percentage of its yield, and the produc;iveness as a function of the dilution rate, temperature, and the concentration of ethanol and phosphoric acid in the medium. The main characteristics of the growth process in the studied factor space were established. The optimum conditions were calculated for growth of the strain with respect to each of the criteria. Under various conditions of bacterial growth, changes in the morphology and ultra-fine structure of the cells correlated with their physiological activity. The volume of the cells increased with the rate of dilution of the medium: the process can be described by a saturation curve. The presence of mesosomal structures is typical of the cells growing at low flow rates.