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The article presents the results of the study the ability of four not studied strains of enterococci (E. durans, SB6, E. faecium SB12, E. durans SB18, E. durans SB20), which were isolated from the Carpathian brynza, to reduce the acidity of medium of cultivation, the rate of biomass accumulation and the ability to exhibit antagonistic properties to the opportunistic microflora. Lactic acid and minor compounds are producing in a result of lactose fermentation, which form the specific taste and aroma properties of the product. The activity of acid formation has crucial because it directly connected with the coagulation of proteins and the prevention of the growing of extraneous microflora. Therefore, the rate of acidity increasing of the medium is one of the most important characteristics in selection of strains of lactic acid bacteria for the manufacture of dairy products. High growth rate, resistance to the contamination of extraneous microflora and preservation of their properties in the finished product are the technological properties of the strains. The inhibition of the growth of pathogenic cultures of microorganisms is the main probiotic functions of beneficial bacteria namely antagonistic activity. It was found, that the strain E. durans SB20 manifested the highest ability to increase the acidity of the medium under the cultivation for 24 hours at 37 °C as it reduced the pH on 30.3 %, and the strain E. durans SB18 increased the acidity on 29.9 %. Under 48 hours strains E. durans SB20 and SB18 increased the acidity on 31.1 and 30.5 % (P< 0.001) respectively compared with the control. The growth rate of stains E. durans SB20 and E. durans SB18 were in 18,0 and 17,6 times higher than in control under the cultivation for 24 hours at 37 °C, the optical density were in 18.3 and 18.2 times higher respectively than in the control sample under the cultivation for 48 hours at the same temperature. Furthermore, strains of enterococci showed antagonistic properties against conditionally pathogenic cultures of microorganisms on 24 and 48 hour of cultivation. In addition, it was found that with an increasing temperature of the antagonistic activity of the strains cultivation increased. Obviously, it was connected that more biologically active substances and microbial secondary metabolites are formed under the longer cultivation and higher temperatures. In particular on 48 hours at 37 °C almost of all the tested strains showed moderate antagonistic activity against E. coli, S. enteritidis, E. aerogenes, P. mirabilis and P. aeruginosa. However, all four strains didn`t have antagonistic activity against the test-strain S. aureus.

The work aimed to investigate the effect of the “Metisevit” feed additive on the activity of the enzymes of the antioxidant system of the blood of piglets under conditions of nitrate-nitrite load. The research was carried out on 60-day-old piglets of the large white breed. For the experiment, 10 clinically healthy piglets were selected, from which 2 groups of five animals were formed. Piglets of the control group were fed sodium nitrate at a dose of 0.3 g NO3-/kg body weight for three months. Piglets of the research group were also fed sodium nitrate at a dose of 0.3 g NO3-/kg of body weight, together with Metisevit at a dose of 0.36 g/kg of feed for three months. The “Metisevit” feed additive was developed at the Department of Pharmacology and Toxicology of the Stepan Gzhytskyi National University of Veterinary Medicine and Biotechnology Lviv, which contains vitamin E, selenium, and methiphene (methionine, phenarone, zeolite). Under the conditions of feeding piglets with sodium nitrate feed at a dose of 0.3 g of NO3ˉ/kg, a decrease in the activity of enzymes of the antioxidant defense system was established: superoxide dismutase by 14.8 %, catalase by 20%, glutathione peroxidase by 15.1 %. Metisevit in piglets increased the activity of the enzyme link of the antioxidant protection system, preventing the development of oxidative stress that occurs in nitrate-nitrite toxicosis. During our experiments, it was found that the introduction of Metisevit into the diet of piglets with excessive consumption of nitrates prevented the development of chronic nitrate-nitrite toxicosis. It was established that Metisevit increases the activity of enzymes – superoxide dismutase, catalase, and glutathione peroxidase. These enzymes reduce the high level of lipid peroxidation products in the body of piglets under conditions of nitrate-nitrite load.

The article presents data on the use in the cheese-making technology starter culture “Enteroplan”, which includes strains of lactic acid bacteria isolated from traditional Carpathian cheese, particularly L. lactis, Lb. plantarum, E. durans in the ratio 50 : 40 : 10. The microflora of traditional dairy products, particularly cheese, has evolved through time and is unique. It is essential to reproduce and preserve such a microbiome in cheese making. A change in the technology was the use of cow's milk by introducing our starter culture, “Enteroplan”. For the manufacturing of bryndza, cow's milk was chosen, which satisfied regulatory documentation criteria in terms of organoleptic characteristics, physicochemical properties, and cheese suitability. According to organoleptic parameters, the manufactured prototype of cheese with starter culture “Enteroplan” had a pronounced, rich creamy-cheese taste and smell; its consistency was homogeneous, plastic, moderately dense, whereas the control cheese made with RSF had a less pronounced taste and smell, and its consistency was homogeneous, plastic, and moderately fragile. No significant discrepancies were found in other organoleptic indicators. According to the results of the scoring of the cheese, the prototype received 3 points more. The taste, odor, and consistency of the test sample were examined above compared to the control sample. During the 20-day maturation period of the cheese, the number of lactic acid bacteria was relatively high, ranging in the control sample from (6.6 ± 0.28)×105 to (2.5 ± 0.23)×105 CFU/g and in the experimental sample from (8.1 ± 0.30)×105 to (6.1 ± 0.18)×105 CFU/g. Pathogenic microflora, mold, and yeast-like fungi were not detected during the storage of the manufactured cheese samples.

In order to give the product functional properties, promising for the industry strains of cultures of lactic acid bacteria L. lactis ssp. lactis IMAU 32258, Lb. plantarum KLDS 1.0728 and E. durans SB18, isolated from traditional Carpathian bryndza. It was found that under conditions of co-cultivation, the studied strains were compatible, ie did not show interspecific antagonism. Based on these probiotic strains, five compositions of L. lactis ssp. lactis IMAU 32258, Lb. plantarum KLDS 1.0728 and E. durans SB18 in the ratios,%: composition № 1 – 50:25:25; № 2 – 33:33:33; № 3 – 50:40:10; № 4 – 50:10:40 and № 5 – 70:15:15 respectively. When determining the rate of biomass accumulation, it was found that at a temperature of 32 ° C the highest growth intensity was registered in the cultivation of compositions № 1, № 2 and № 4, it exceeded the control by 19.5–20.1 times (P