Bacteriocinogenic activity of Enterococcus faecalis strains from chourico, traditional sausage produced in Southern Portugal

Abstract

Enterococcus faecalis isolates from chourico (traditional Portugal fermented sausage) were studied here with the main impact on bacteriocin production. In bacteriocin-producing strains phenotypic antibiotic profile was tested to check if they are sensitive or resistant. Lactic acid production ranged from 0.581 mmol/L up to 0.783 mmo/L. Enterococci grew sufficiently in the medium with 1% concentration of oxgall/bile. From 14 E. faecalis, bacteriocin substances (Bs) by 8 strains were found to inhibit the growth at least 1 indicator of 27 (inhibitory zones-10 to 18 mm) by the qualitative method. The effect of Bs of 8 active E. faecalis strains was tested also by the quantitative method; Bs of 6 E. faecalis inhibited the growth at least of 1 indicator; E. faecalis P06/7, P06/13, P06/16 inhibited the growth of Enterococcus avium EA5, Listeria innocua LMG13568, Staphylococcus aureus SA5 (activity: 100 to 1600 AU/ml). The highest activity (1600 AU/ml) showed Bs produced by P06/16 against LMG13568. Taking into account the antibiotic sensitivity and activity in the strain itself, the most promising strains for detailed bacteriocin studies are E. faecalis P06/16, P06/7, P06/13 which are mostly antibiotic sensitive and bacteriocin active.