TAXONOMIC RESEARCH, BIOLOGICAL PROPERTIES AND BIOSYNTHETIC ACTIVITY OF LACTIC ACID BACTERIA AND BIFIDOBACTERIA ISOLATED FROM VARIOUS NATURAL ECOLOGICAL NICHES

Abstract

Lactic acid bacteria (LAB) and bifidobacteria play an important role in human health and have wide application in food industry. LAB propagation and high quantity of them in natural substrates testifies that many species of these microorganisms have adapted to the environmental conditions, and specific ecological niches. Lactic acid bacteria isolated from different ecological niches were identified using phenotypic and molecular–genetic methods. The species of Lactobacillus plantarum, Enterococcus faecium, E. durans, E. hirae, E. faecalis were identified among LAB. Bifidobacteria were majorly represented by Bifidobacterium infantis, B. breve, B. animalis, B. bifidum and B. dentium species. The intraspecific heterogeneity of LAB and bifidobacteria strains isolated from distal part of intestinal tract of people belonging to various age group was investigated. The role of teichoic acids in adhesion of the studied LAB strains to human’s buccal epithelium was evaluated. Different biological activities, such as gastric juice resistance, tolerance to bile acids, adhesive properties to macroorganism’s epithelial cells, sensitivity to clinically significant antibiotics were studied. All of these properties make specific LAB and bifido-bacteria strains to be promising for probiotics and functional foods creation.