Isolation and identification of lactic acid bacteria Lactococcus lactis subsp. lactis with antimicrobial properties
The paper presents the results of screening of lactic acid bacteria with antimicrobial effects contained in cow and mare milk by an example of national products of mixed lactic and alcoholic fermentation Kurunga, Kumiss and Doogh of therapeutic and prophylactic purposes from different territorial zones of Russia (Moscow region, Buryatia, Bashkortostan), and Iran. The separation of Lactococcus with antimicrobial effects has been performed in stages using selective media and test cultures of bacteria and fungi (Bacillus coagulans, Escherichia coli, Aspergillus niger). Twenty Lactococcus cultures having antimicrobial effects on pathogenic microorganisms including the fungicidal ones such as Lactococcus subsp. lactis. have been identified using classical microbiological methods and basing on the analysis of a 16S rRNA gene fragment. The research has also determined the level of lactic acid accumulation and the range of antimicrobial action of the cultures. Nucleotide sequences of the most promising strains for the development of new biopreservatives have been deposited in the GenBank.