Comparative Analysis of the Lytic Profiles of Bacteriophages of Industrially Significant Strains of Lactic Acid Bacteria

Bacterial starters for fermented dairy products are specially selected consortia of lactic acid bacteria. Lactococcus bacteriophages are widespread in dairies and are the main cause of the inhibition of lactic acid fermentation. To select lactococcal cultures for cheese starters, a group of 25 bacteriophages isolated from various enterprises in the European part of Russia in the period from 1985 to 2016 was formed and their lytic spectrum was analyzed using phage-sensitive lactococcal strains. Based on the study, it can be concluded that there is a wide diversity of lytic profiles of bacteriophages at dairy enterprises in the European part of Russia. Despite the wide geographical coverage and wide time period of bacteriophage isolation, no regularities in the spectra of the bacteriophage lytic activity are revealed when using the lactococcal test panel. The results of the work demonstrate the need for the preliminary testing of starter cultures on a wide panel of bacteriophages to identify cultures of lactic acid bacteria with the maximum level of resistance to infection by bacteriophages.