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 bifdobacteria play an important role in human health and have wide application in food industry. LAB propagation and high quantity of them in natural substrates testifes that many species of these microorganisms have adapted to the environmental conditions, and specifc ecological niches. Lactic acid bacteria isolated from different ecological niches were identifed using phenotypic and molecular–genetic methods. The species of Lactobacillus plantarum, Enterococcus faecium, E. durans, E. hirae, E. faecalis were identifed among LAB. Bifdobacteria were majorly represented by Bifdobacterium infantis, B. breve, B. animalis, B. bifdum and B. dentium species. The intraspecifc heterogeneity of LAB and bifdobacteria 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 signifcant antibiotics were studied. All of these properties make specifc LAB and bifdobacteria strains to be promising for probiotics and functional foods creation.