This article discusses the current data on the biochemical properties of bacteria of the genus Lactobacillus and their use in industry, particularly in dairy production and biotechnology. Microorganisms of the genus Lactobacillus have antagonistic activity against pathogenic microorganisms and perform an immunomodulatory function. The positive effect of lactobacilli on human health explains their active use in probiotics. The positive effects of normal intestinal microflora and probiotics are mainly due to bifidobacteria and lactobacilli. In probiotic therapy, various types of bacteria of the genus Lactobacillus are used, such as: L. acidophilus, L. rhamnosus, L. plantarum, L. fermentum, L. delbrueckii subsp. bulgaricus, L. casei, L. paracasei. In recent years, the biotechnology of probiotics has been intensively developing - drugs used for the correction and prevention of microecological disorders in the gastrointestinal tract of humans and animals. An urgent issue is obtaining new data on the biological properties of lactobacilli, creating new probiotic preparations based on them using modified approaches to cultivation. The results of determining the species L. acidophilus L. casei, L. rhamnosus, L. paracasei, obtained by the classical biochemical identification method based on saccharolytic activity, complicating species identification, are comparable to the molecular genetic method. In the case of L. casei, L. rhamnosus, L. paracasei, it is necessary to carry out modern identification methods based on the polymerase chain reaction, since their biochemical properties are similar, which makes it difficult to carry out species identification. The molecular genetic method is a valuable addition to the intergeneric and species identification of lactobacilli, given the variability of the classical biochemical method.