Abstract
Today, probiotic microorganisms, including lactic acid bacteria, are becoming increasingly important in the food industry and biotechnology. They play an important role in the formation of the microflora of the gastrointestinal tract, inhibit the growth of pathogenic microorganisms, improve the absorption of nutrients, and contribute to the overall health of consumers. Effective selection of probiotic strains is based on their physiological stability (acids and salts of bile acids), adhesive ability, and technological properties. In this regard, a comprehensive assessment of the probiotic potential of lactic acid bacteria is an important step in selecting promising strains for inclusion in food products. In this study, Lactobacillus acidophilus SLA, Lacticaseibacillus casei SLC және Lactobacillus delbrueckii subsp. bulgaricus SSV (hereinafter Lactobacillus - L) were used. The main probiotic properties of the strains were comprehensively evaluated in vitro. During the study, the Turner method revealed the activity of acid formation and conducted tests for resistance to acids and salts of the gallbladder to simulate gastrointestinal conditions. The ability of adhesion to erythrocytes was evaluated using the Brilis method. According to the results obtained, the L. acidophilus SLA strain is highly resistant to acids and bile salts (viability at pH 2.0 - 82.4%, viability at 0.5% - 90.4%) and showed a high level of adhesion (UAC = 4.3). Although the L. casei SLC strain has medium resistance and adhesion, the L. bulgaricus SSV strain had high acid-forming activity (124 °T), but low resistance to stress factors and adhesion. In general, the data showed that in a comprehensive assessment of the probiotic potential of lactic acid bacteria, it is necessary to take into account such important criteria as stability and adhesion of acids and bile salts. The results of the study allow us to evaluate the L. acidophilus SLA strain as a promising candidate for introduction into food.