Scientific Journal of KubSAU

The wide variety of microorganisms has been identified in many wine-making countries on the berries of grapes. These are yeasts of different families, forms and kinds, bacterium, mold fungi. In the article, we present the results of investigating species composition of microflora of berries of white and red types of grape, which grows in different economies of the Krasnodar region and the republic of Abkhaziya. The sowings onto the elective media were conducted for the development of entire spectrum of yeast. The grown colonies after preliminary microscoping were separated into the cultures and subjected to testing according to the culturalmorphological signs, being guided by determinants and benefits. It was established the specific variety of microflora on the surface of the berries of grapes of all investigated types, without dependence on the place of their growth. Obtained data showed that the group of yeast, which constantly is present in the complex of the epiphytic microorganisms of grapes of Saccharomyces, Pichia, Hansenula, Hanseniaspora was characteristic for all types of grapes in all investigated regions. The heterogeneity of the taxonometric composition of microflora is shown. Prevailed yeasts were of family Saccharomycetaceae, form Saccharomyces vini. A quantity of yeast of Saccharomyces vini decreases in a number of Myskhako-Caucasus-Fanagoriya, that as a whole will be coordinated with the climatic conditions. Only the type of Pinot nuar grapes had yeasts of Brettanomyces Dekkera. On the berries of Cabernets and Karaburnu we have discovered yeasts of Schisosaccharomyces acidodevoratus, causing acid-reduction. On the berries of the grapes, which grew in joint stock company APF “Fanagoriya” we haven’t revealed the presence of lactic acid bacteria Lactobacillus brevis and yeasts of the form of Schisosaccharomyces acidodevoratus. In the same farm the smallest quantity of yeastswreckers is noted, which we the forms of Pichia and Candida. In the microflora of Cabernets, Risling and, especially, Karaburnu grapes, we have found lactic acid bacteria Lactobacillus plantarum and Lactobacillus brevis. Lactobacillus plantarum. Among the bacteria the total quantity of coccic flora composes - 56 %, the rod-shaped - 44 %. Two types of active acetous bacteria are identified – Acetobacter aceti and Acetobacter xelinum. Especially high was their surface concentration on the berries of Kachich type of grapes

The article investigates the possible pathways for the formation of crotonaldehyde in wine production in the result of the activity of wine yeast and lactic acid bacteria. It established that exposure to exhaust gases, noble rot, pathogens and pests on grape plant does not lead to the biosynthesis of crotonaldehyde in grape berry. The experimental data to identify probable pathways for the formation of crotonaldehyde during vinification has been presented. The effect of the test substance on the life of yeasts and lactic acid bacteria has been estimated

The influence is shown for the race of yeasts to the dynamics of the fermentation of grape must, the composition of organic acids and aromatic of components. The races, which ensure obtaining high-quality winemakings material are presented

In the article, we have studied the influence of biological nitrogen deposition on the physical and chemical parameters of natural semi-sweet wine, on the example of two grape varieties – classic European Chardonnay and interspecific hybrid Ekaterinodar, including amino acids and aroma-forming components. It is established, that the use of the proposed technology contributes to the active consumption of amino acids by yeast in the fermentation stage. At the same time, yeast cells consumed most actively alanine, valine, phenylalanine, histidine, aspartic, aminobutyric, glutamic acids, leucine, lysine, Sirin, tyrosine, threonine. A slight increase in the concentration of amino acids was observed at the end of fermentation, when the yeast cells entered the stationary phase of development. However, the content of all amino acids, with the exception of Proline, in the wine material was less than in grapes and fermenting wort. As a result of biological nitrogen deposition in experimental versions, the concentration of nitrogen compounds (total and amine nitrogen) was three times less than in the control ones. There is a difference in the concentration of flavor-forming components in wines prepared from both grape varieties using different technologies. In experimental versions, we observed a greater accumulation of almost all components of the aroma-binding complex (especially esters, terpenes, phenylethanol, and ionone), with the exception of higher alcohols. Experimental samples of natural semi-sweet wines from the Chardonnay and Ekaterinodar grape varieties were characterized by a bright floral and fruit aroma and had a higher tasting rating in comparison with the classic technology

The results of the study of amino acids of white table wines depending on the yeast strain, continuous contact of wine with yeast biomass and the presence of lees stirring are presented. The dynamics of amino acids, which affect wine organoleptic characteristics and the formation of wine defects, specifically, tyrosine, methionine, threonine and lysine is shown. Conducted researches made it possible to divide the amino acids into three groups depending on the carrying out the batonnage or lack of it. The first group consisted of amino acids, the concentration of which practically has not changed in the presence or lack of stirring. The second and third groups include amino acids, the concentration of which increased and decreased, respectively during batonnage. The stirring of the wine with yeast biomass facilitated to the activation of mass transfer processes between cell and medium, and the access of air lead to oxidation of some amino acids and the change of its concentration. The absence of stirring influenced to a slight increase in the concentration of such amino acids as cystine, cysteine, β-phenylalanine, serine, α-alanine, leucine and glutamic acid. The experimental data allowed to arrange amino acids in a row depending on the speed of release into the medium: ά-aminobutyric acid > glutamic acid > α-alanine > leucine

We have established a change in the concentration of nitrous connections - amino, ammonium, total nitrogen and protein - during the fermentation of grape must by different races of yeast. Yeast which ensure reduction in the number of nitrous connections at the stage of the active fermentation were isolated

The study was performed to genotype some commercial wine yeast strains with SSR-markers. Five polymorphic SSR-markers were tested in a selection of 15 yeast strains. Tested SSR-markers showed a high level of informativeness as well as polymorphism and can be used further to analyze the genetic diversity of wine yeast

The study was performed to genotype some commercial wine yeast strains using the assay of Interdelta genomic sequences. Experimental parameters of PCR to identify were optimized and optimal simplified method of DNA extraction from dried preparations of yeast cultures was define. Proven method showed a high level of resolution and can be used for the analysis of genetic diversity wine yeast in combination with SSR-markers