Study of antimicrobial activity and tolerance to stress factors of Lactobacillus strains for the development of new probiotics

Abstract

Probiotic strains, the main component of which are beneficial lactic acid bacteria, are of considerable interest in biotechnological production. Among various probiotic microorganisms, special attention is paid to Lactobacillus, which have many positive properties. The object of the study is lactic acid bacteria of the genus Lactobacillus isolated from biological samples, as well as collection strains of the Biobank of the Republican Collection of Microorganisms. The aim of the study is to isolate and characterize the probiotic properties of lactic acid bacteria for the development of probiotics. In the course of work, 15 probiotically active strains of lactic acid bacteria were screened and four most active cultures (Lactobacillus casei 2LB, Lactobacillus brevis 3LB, Lactobacillus fermentum BV-4, Lactobacillus plantarum 5LB) were selected among the strains of the Biobank of the Republican Collection of Microorganisms. A consortium of starter cultures of these strains was created and the optimal variant was selected for inclusion in the probiotic under development. The probiotic potential of bacteria was studied, including resistance to low pH values, osmotic pressure, such properties as autoaggregation and coaggregation to opportunistic microorganisms. Studies were conducted to investigate the survival of Lactobacillus in the aggressive environment of the gastrointestinal tract, their adhesive properties, ability to produce antimicrobial substances and modulate the immune response. The results showed that Lactobacillus strains can effectively suppress pathogenic microflora, colonize the intestine and stimulate immune processes. This holds promise for the development of novel Lactobacillus-based probiotic preparations to improve human health. These results emphasize the importance of studying the probiotic potential of Lactobacillus and their strain-specific properties, which are essential for the development of functional products.