[Micromycetes and actinobacteria under conditions of many years of natural cryopreservation]. / Mikromitsety i aktinobakterii v usloviiakh mnogoletnei estestvennoi kriokonservatsii.

Almost all of the investigated samples of the Arctic and Antarctic permafrost sediments of different genesis with ages from 5-10 thousand to 2-3 million years were found to contain viable micromycete and bacterial cells. The maximum amounts of viable cells of fungi (up to 10(4) CFU/g air-dried sample) and bacteria (up to 10(7)-10(9) CFU/g air-dried sample) were present in fine peaty sediment samples taken from different depths. The identified micromycetes belonged to more than 20 genera of the divisions Basidiomycota, Ascomycota, and Zygomycota, and some represented mitosporic fungi. Thawing the samples at 35 and 52 degrees C allowed the number of detected fungal genera to be increased by more than 30%. Aerobic heterotrophic prokaryotes were dominated by coryneform, nocardioform, and spore-forming microorganisms of the order Actinomycetales. Analysis of the isolated fungi and actinomycetes showed that most of them originated from the microbial communities of ancient terrestrial biocenoses.

[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.

[Physiology of the growth and supersynthesis of DNA-polymerase in Escherichia coli during 2-stage continuous cultivation]. / Izuchenie fiziologii rosta i sverkhsinteza DNK-polimerazy Escherichia coli pri dvukhstadiinom protochnom kul'tivirovanii.

The physiology of growth under the conditions of batch and continuous cultivation was studied with the recombinant strain of Escherichia coli CM 5199 capable of DNA polymerase I superproduction. The specific growth rate of the strain is 0.8 h-1 under the conditions of continuous cultivation which is almost 2.5 times greater than that in the exponential phase of batch cultivation. When the strain was cultivated at a flow rate above 0.3 h-1, the biomass concentration in the fermenter decreased and the culture was no more limited by the carbon source in the absence of other growth limiting components of the medium. Apparently, the metabolic product ceased to inhibit high growth rates of the culture under the conditions of continuous cultivation. The rate of DNA polymerase synthesis correlated with the specific growth rate and the respiration activity of the culture when the lambda pol A prophage was induced in the cells. The authors discuss the effectiveness of ribosome operation in the cells at a growth rate of 0.05 to 0.3 h-1 and the content of ribosomes at a higher growth rate in relation to DNA polymerase I synthesis.

[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.