Description: The main objective of the present study is the proteolytic potential of Lactobacillus isolates for degradation of whey proteins. To implementation this goal, the following tasks were set: Isolation of lactobacilli strains from cow and sheep, buffalo yoghurt and lactic acid products, characteristics of newly isolated strains, survival at different temperatures, acidification of the nutrient medium, monitoring the production of biologically active peptides, study of the proteolytic activity of the strains, hydrolysis of basic whey proteins, hydrolysis of whey proteins (beta-lactoglobulin and alpha-lactalbumin). Of the 30 samples used, 27 lactobacilli strains were isolated to pure cultures. Antimicrobial activity of strains R4.2 against E. coli. The studied strains have proteolytic potential and some of the studied strains can hydrolyze whey proteins as beta-lactalbumin and beta-lactoglobulin. Low molecular weight molecular moieties are formed after cultivation in the presence of beta-lactalbumin analysed using Tris-Tricine PAGE