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 14E. 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 to1600 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.

Key words: Enterococcus faecalis, bacteriocin, chourico,sensitivity, oxgall