Antibacterial Effect of Bacteriocinogenic Enterococci from Different Sources on Listeria monocytogenes

Abstract

In this study, antimicrobial activity of partially purifiedenterocins and crude bacteriocins from Enterococcus isolateswith different sources was investigated against Listeriamonocytogenes by disk diffusion assay. Totally 70% ofenterococcal isolates (Enterococcus faecalis andEnterococcus faecium from food and clinical sources) werefound as potential bacteriocinogenic strains. Both of foodand clinical enterococcal isolates also exhibitedantimicrobial properties against L. monocytogenes.Additionally, the present study detected that inhibitoryactivity was strain-specific. Both crude bacteriocins andpartially purified enterocins from E. faecium isolates showedlower antimicrobial activity against L. monocytogenes thanE. faecalis isolates. The inhibition diameters obtained withcrude enterocins and partially purified enterocins wererespectively ranging from 12.33 mm to 13.25 mm and from8.66 mm to 9.25 mm. Crude bacteriocins retainedantibacterial activity after heat treatment except 120 oC andalso remained functional at pH values between 3 and 11. Asa result, it was considered that enterocins could be benefit inheated and acidic or basic food products as biopreservative.