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Antagonistic properties and peculiarities of inter-strain interactions of probiotic microorganisms were investigated. The study of the antagonistic activity of probiotic strains was carried out by the methods of perpendicular strokes (or delayed antagonism) and the diffusion method (block modification) in relation to opportunistic and pathogenic microorganisms. Most probiotic strains had moderate to high antagonistic activity against both gram-positive and gram-negative pathogens. The results obtained allowed us to select the most active strains, namely L. plantarum AS-41, L. acidophilus A-14, B. subtilis S-2 and B. subtilis S-18, which have a high probiotic potential. To assess biocompatibility, the method of co-cultivation of the selected strains on a modified agar MRS medium was used. The strains that showed biocompatibility of the type “mutual neutrality” or “contact progression” were selected to create a consortium of probiotic microorganisms. Further study of the investigated strains of probiotic bacteria opens up the possibilities of their use for the manufacture of a combined preparation for veterinary purposes, for the prevention and treatment of diseases of the gastrointestinal tract of farm animals.

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The neutralizing ability of the mycotoxin zearalenone with the KPM-2 biological preparation was studied. Changes in the cytotoxic properties and biochemical parameters of cell cultures under the influence of zearalenone on the background of the use of the drug KPM-2 were studied. As a result of the conducted studies, it is clear that the cytotoxicity of zearalenone in the minimum dose did not differ from the control and at the maximum dose of 3*10-3 M, cell death was higher by 75% in comparison with the control. When using the drug KPM-2 in a concentration of 2*10-9 CFU/ml, the cytotoxicity of zearalenone decreased only by 44.9% in comparison with the control. When zearalenone was exposed to cell culture at a dose of 3*10-3 M, the activity of the enzyme alanine aminotransferase (ALT) increased by 51.7% compared to the control group, and when using the drug KPM-2 at a concentration of 2*10-9 CFU/ml, ALT activity was higher than control by only 32.1%, respectively. The activity of aspartate aminotransferase (AST) in the group with a concentration of zearalenone 3*10-3 M increased by 53.9% compared to the control group, when using the drug KPM-2, the neutralization of the toxic effect of zearalenone was observed and the AST index increased by only 44.0%. The concentration of lactic acid when exposed to zearalenone at a dose of 3 * 10-3 M decreased by 26.1%, and in the group after neutralization of zearalenone with KPM-2 in a concentration of 2*10-9 CFU/ml, the decrease in this indicator was only 16% compared to the control. The concentration of lactic acid when exposed to zearalenone at a dose of 3 * 10-3 M decreased by 26.1%, and in the group after neutralization of zearalenone with KPM-2 in a concentration of 2*10-9 CFU/ml, the decrease in this indicator was only 16% compared to the control. It is proposed to use the drug KPM-2 in the form of a suspension, which has the ability to neutralize the mycotoxin zearalenone and reduce the toxic effect on living organizations.

We have identified the optimal conditions for the production of chitinolytic enzymes of T.viride in submerged state fermentation. The production of chitinase by a new strain of fungus was carried out on the basal liquid medium, containing (%) colloidal chitin 0.5, NaNO3 0.2, KH2PO4 0.1; MgSO44-7H2O 0.05 and KCl, 0.05. The activity of enzymes of the chitinase complex of the strain was evaluated using the method using dinitrosalicylic acid (DNS reagent). A quantitative determination of the activity of chitinases in a producer microorganism was established by their ability to hydrolyze 0.2% colloidal chitin (in phosphate buffer 0.05 M, pH 5.2), by the content of reducing sugars formed in this process, which were evaluated using a DNS reagent. The results of studies of the influence of various cultivation parameters showed that highest chitinolotic enzymes production by T.viride was obtained at pH 4.0, (301.15-303.15) K and after 144 h growth. The studied soil isolate can be further used in biotechnological research, as well as for biological control of pests and pathogens of agricultural crops.