AUTHOR=Garmasheva Inna L. , Oleschenko Ljubov T. 

TITLE=Screening of bacteriocin-producing dairy Enterococcus strains using low-cost culture media

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1168835

DOI=10.3389/fmicb.2023.1168835

ISSN=1664-302X

ABSTRACT=<p>This study was carried out to select the bacteriocinogenic strains among <italic>Enterococcus</italic> strains isolated from Ukrainian traditional dairy products using a low-cost media for screening, that containing molasses and steep corn liquor. A total of 475 <italic>Enterococcus</italic> spp. strains were screened for antagonistic activity against <italic>Pseudomonas aeruginosa</italic>, <italic>Escherichia coli</italic>, <italic>Staphylococcus aureus</italic>, and <italic>Listeria monocytogenes</italic> indicator strains. The initial screening revealed that 34 <italic>Enterococcus</italic> strains during growth in low-cost medium containing corn steep liquor, peptone, yeast extract, and sucrose produced metabolites with inhibition activity against at least of the indicator strains used. Enterocin genes <italic>entA</italic>, <italic>entP</italic>, and <italic>entB</italic> were detected in 5 <italic>Enterococcus</italic> strains by PCR assay. Genes of enterocins A and P were found in <italic>E. faecalis</italic> 58 and <italic>Enterococcus</italic> sp. 226 strains, enterocins B and P – in <italic>Enterococcus</italic> sp. 423, enterocin A – in <italic>E. faecalis</italic> 888 and <italic>E. durans</italic> 248 strains. Bacteriocin-like inhibitory substances (BLIS) produced by these <italic>Enterococcus</italic> strains were thermostable and sensitive to proteolytic enzymes. To our knowledge, this is the first report on the isolation of enterocin-producing wild <italic>Enterococcus</italic> strains from traditional Ukrainian dairy products using a low-cost media for screening bacteriocinogenic strains. Strains <italic>E. faecalis</italic> 58, <italic>Enterococcus</italic> sp. 423, and <italic>Enterococcus</italic> sp. 226 are promising candidates for practical use as producers of bacteriocins with inhibitory activity against <italic>L. monocytogenes</italic> using molasses and steep corn liquor as cheap sources of carbon and nitrogen, that can significantly reduce the cost of industrial bacteriocin production. Further studies will be required to determine the dynamic of bacteriocin production, its structure, and mechanisms of antibacterial action.</p>