A positive effect of flaxseed mucilage (FSM) addition (at concentrations of 0.1, 0.2, and 0.4%) to MRS and milk whey nutrient medium on the survival, auto-aggregation, hydrophobicity, adhesive, and antioxidant properties of L. bulgaricus, L. fermentum AG8, and L. plantarum AG9 was shown. It was found that the AG 8 strain became less sensitive to 7% NaCl concentrations (the cell survival rate in the experiment with 0.4% flaxseed mucilage increased by 10% compared to the control). Cultivation in the presence of FSM led to an increase in auto-aggregation, especially in the case of AG8 (from 60 to 85%) and AG9 (from 50 to 80%) strains, and an increase in hydrophobicity was seen: for L. fermentum AG8, it was from 30% to 62–72%, for L. fermentum AG9 from 30% to 35–42%, and for L. bulgaricus from 20% to 30%. The adhesive properties of the L. fermentum AG8 and L. plantarum AG9 cells increased from 0.472 to 1 nN (nanonewton) and from 0.630 to 2.5 nN, respectively. The presence of flaxseed mucilage increased the total phenolic content in cell-free supernatants after 48 h of cultivation. The concentration of 0.1–0.2% FSM increased the OH-scavenging activity of milk whey nutrient medium cell-free supernatants of strains AG8 and AG9 by 7–10%. Flaxseed mucilage can serve as a promising bioactive additive that elevates antioxidant activity, increases the resistance and survival of Lactobacillus cells in the gastrointestinal tract, and leads to the synthesis of lipase and α-glucosidase inhibitors. The co-culture of these lactic acid bacteria in the presence of FSM and milk components in the form of whey leads to the synthesis of lipase and α-glucosidase inhibitors more than the culturing on de Man, Rogosa, and Sharpe broth.

The exopolysaccharides (EPS) produced by lactic acid bacteria (LAB) and released into fermented milk play a protective role from stress factors as well as improve emulsifying and thickening properties of the product, reduce syneresis, and increase elasticity. Here we report the relationship between the properties, composition, and microstructure of EPS produced by six different strains of lactobacilli (L. bulgaricus and five strains isolated from silage). The presence of fructose together with negative-charged uronic acid was found to play a significant role in changing the EPS properties. Thus, the increased fraction of rhamnose and arabinose and a decrease in xylose leads to compaction of the EPS, decreased porosity and increased both OH- and superoxide scavenging and Fe-chelating activities. By contrast, increased xylose and low rhamnose and arabinose apparently leads to loss of large aggregates and high DPPH activity and FRAP. The high content of glucose, however, provides the formation of large pores. The increased fructan fraction (69.9 mol%) with a high fraction of galacturonic (18.2 mol%) and glucuronic acids (6.7 mol%) apparently determines the highly porous spongy-folded EPS microstructure. Taken together, our results indicate that both the quantitative characteristics of the individual components of the fraction and the structural features of EPS are important for the antioxidant potential of fermented milk and depend on the strain used for milk fermentation, suggesting the advantage of a multicomponent starter to achieve the optimal beneficial properties of fermented milk.

Data on the dynamics of furfural yield from wheat straw, corn cobs, birch sawdust, oat husk and sugar beet pulp in a narrow temperature range (180 – 190 ° C) were obtained. Low-concentrated solutions of sulfuric and phosphoric acids were used. Enzymatic hydrolysis of cellulosic residues was conducted. It was shown that the maximum yield of glucose in birch sawdust was 21.8%, in the corn cobs 18.6%, in wheat straw 19.4%, in sugar beet pulp 15.8 % of absolutely dry substance respectively.

The possibility of fixing genotoxic changes in Saccharomyces cerevisiae yeast under the influence of physicochemical factors was evaluated using the DNA-comet assay. Peripheral blood leukocytes of mice subjected to similar effects were used as an object of comparison. The data obtained showed that under the action of both the alkylating agent and X-ray irradiation, the changes were more pronounced in experiments with leukocytes of the blood of mice. At a methyl-methane sulphonate concentration of 10 mM, the comet tail length in mouse peripheral blood leukocytes was about 40 μm, while the yeast spheroplasts tail length of a comet was 0.16 μm. The DNA content in the tail of the comet did not exceed 5 % for yeast after treatment with an alkylating agent at a concentration of 40 mM, which is 10 times less than in peripheral blood leukocytes of mice under similar conditions. Under the action of X-ray radiation, the length of the comet’s tail and the DNA content in it for spheroplasts of yeast also differed significantly from the leukocytes of the peripheral blood of the mouse. Thus, the comet test allows to register a significant increase in the level of DNA damage in yeast spheroplasts under the action of physicochemical factors in relatively high doses.

The conditions (solid to liquid ratio, acid concentration, temperature, process duration) were selected for the effective high-temperature pretreatment of corn cobs with dilute sulfurous acid. The activity of the enzymatic complexes «CellicCTec2» and «CellicHTec2» of the company «Novozymes» in the process of corn cobs hydrolysis was studied. The maximum yield of reducing sugars was 45 % of absolutely dry substance at a concentration of the enzymatic preparation «CellicCTec2» 3 % (of corn cobs absolutely dry substance) and solid to liquid ratio 1:30. The total amount of extracted reducing substances is 66 % of the theoretical yield of carbohydrates in the corn cobs.