Scientific journal

50 2011

Journal of Food and Nutrition Research
Summary No. 1 / 2011

Antibacterial activity and enterocin genes in enterococci isolated from Bryndza cheese
Journal of Food and Nutrition Research, 50, 2011, No. 1, s. 21-32

Roman Dušinský, Institute of Cell Biology and Biotechnology, Faculty of Natural Sciences, Comenius University, Mlynská dolina, SK – 842 15 Bratislava, Slovakia. E-mail:, Tel: +421 2 6029 6724, Fax: +421 2 6029 6288

Summary: Antimicrobial activity of 112 Enterococcus faecium and 33 E. faecalis isolates from Slovakian bryndza cheese was determined against fifteen strains of lactic acid bacteria (LAB) and nine potential bacterial pathogens by the well diffusion agar assay. The observed inhibitory activity was strain-specific. The cell-free supernatants of E. faecium isolates obtained from MRS broth cultures showed higher antimicrobial activity against LAB than supernatants obtained from reconstituted milk cultures, while the opposite was observed for E. faecalis isolates. All supernatants showed a direct inhibitory activity against Listeria innocua, Staphylococcus lentus, E. faecalis V583, Acinetobacter calcoaceticus, Sphingomonas paucimobilis, Escherichia coli, Edwardsiella tarda, Serratia marcescens and Salmonella enterica. Supernatants from enterococcal isolates with pH adjusted to 6.5 possessed bacteriocinogenic activity against L. innocua, Staph. lentus, S. enterica and E. faecalis. In MRS medium, enterococci produced from 5.0 g•l-1 to 9.9 g•l-1 of titratable organic acids. Presence of at least one enterocin structural gene was demonstrated in 63 isolates by PCR. Structural genes for enterocin A, B, P, L50A/L50B and bac31 were detected, entA+entB and entA+entP being the most frequent combinations of the genes. None of the isolates carried the enterocin AS-48 structural gene.

Keywords: Enterococcus sp.; bryndza cheese; antibacterial activity; lactic acid; enterocin genes

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