[Effect of excess ethanol on the growth of yeasts of the genus Candida during continuous cultivation]. / Vliianie izbytka étanola na rost drozhzhei roda Candida pri protochnom kul'tivirovanii.

The effect of flow rates and a specific ethanol load on the growth of Candida utilis and Candida krusei was studied in the process of one-step and three-step cultivation. The productive capacity of fermenters and the economic coefficient of yeast biomass production were shown to depend on the ability of microbial populations to assimilate a certain quantity of a carbon substrate per unit time. When a specific ethanol load exceeds the optimal one, the respiratory activity of a population and the economic coefficient of growth fall down whereas the accumulation of metabolites in the cultural broth increases. The steady state of biomass can be maintained in the process of continuous cultivation by inhibiting the yeast growth with an excess of ethanol.

[Synthesis and secretion of the components of the cellulase complex in Aspergillus terreus]. / Sintez i sekretsiia komponentov tselliulaznogo kompleksa u Aspergillus terreus.

Aspergillus terreus was found to have two functionally different cellobiases. One of them is excreted into the surrounding medium and is a part of the cellulase complex. The second one is an endocellular (or periplasmic) enzyme. It is distinguished by its stability, the time of mRNA operation, the sorption of cell debris; moreover, its activity does not depend on changes in the parameters of the medium when the incubation mixture is replaced and the surface is treated with 0.5 M NaCl. The synthesis of all components in the cellulase complex of A. terreus is coordinated. The time it takes the mRNAs for cellulases to function does not exceed 2 h. A close correlation exists between the synthesis and secretion of polysaccharases (endoglucanases and exoglucosidases) in A. terreus. Cellobiase is adsorbed by the fungal cell wall owing to charge interactions; its desorption depends on the ionic strength and the pH of the medium.

[Fractional protein makeup of Candida utilis yeast protoplasts in the process of their growth and development]. / Izuchenie fraktsionnogo sostava belka protoplastov drozhzhei Candida utilis v protsesse ikh rosta i razvitiia.

Candida utilis IBFMY-405 was grown in a synthetic medium with glucose. Cells taken at the logarithmic phase of growth were studied. The cells were treated with the enzyme from Helix pomatia to prepare protoplasts which were separated by differential centrifugation into groups according to their size. Three protein fractions were isolated from each group and the amino acid composition of the proteins was determined. Proteins of the first fraction (cytoplasmic) prevailed in all of the protoplast groups while the content of proteins of the second fraction (intermediate or myosin-like) was the lowest. As the size of protoplasts increased, difference in the quantitative content of proteins from the first and second fractions became less pronounced. The content of proteins of the third fraction was 3.6 and 2.4 times higher in the protoplasts of the medium size than in the largest protoplasts. The amino acid composition of each protein fraction differed quantitatively and qualitatively in all of the protoplast groups.

Influence of the conditions of growth on the chemical composition and activity of the enzymes of the cell envelope of the yeast Candida tropicalis IBFM-303.

The article is devoted to a study of the changes in the activity and chemical composition of the enzymes of the cell envelope of the yeast Candida tropicalis IBFM-303 during growth on n-alkanes and glucose, as well as the transport of n-alkanes through the cell membrane and the redistribution of the cell contents in the process of budding on the indicated carbon sources.

[Physiologo-biochemical characteristics of Candida tropicalis yeasts, cultivated on n-alkanes at supraoptimal temperature]. / Fiziologo-biokhimicheskie osobennosti drozhzhei Candida tropicalis, vyrashchennykh na n-alkanakh pri supraoptimal'noi temperature.

Cultivation of Candida tropicalis IBEM 303 without thermostatic regulation on n-alkanes results in an increase of the temperature in the fermenter to supraoptimal values and to the linear growth of the culture without distinct differentiation according to the growth phases. The cells grown at supraoptimal temperature differ from the cells cultivated at optimal temperature by the amount of some amino acids and oligopeptides liberated by the yeast into the cultural broth, by the chemical composition of the cells and their morphology.