In-vitro probiotic profiling of novel Enterococcus faecium and Leuconostoc mesenteroides Lactic Acid Bacteria strains from Tunisian freshwater fishes

The potential use of Enterococcus faecium and Leuconostoc mesenteroides (four novel lactic acid bacteria) as an additive in raw and processed foods was here examined. Thus, their antimicrobial activities against a panel of 23 pathogens and food poisoning bacteria was described and their molecular identity achieved by 16S rRNA sequencing and random amplification of polymorphic DNA-polymerase chain reaction (RAPD-PCR). The molecular characterization of their bacteriocins was performed by the enterobacterial repetitive intergenic consensus (ERIC) sequences in PCR. Isolates are belonging to Enterococcus faecium and Leuconotoc mesenteroides species and exhibited high inhibitory activities against food-borne pathogens and spoilage microbial species. All the lactic strains studied were able to survive at pH 3.0 and in the presence of bile salts, pancreatin and pepsin, without any detectable hemolytic activity. Indeed, moderate heat-resistance was observed. Interestingly, their adhesion ability to a steel surface was revealed and their antimicrobial sensitive profiles to clinically-relevant antimicrobial agents were analyzed. The present study indicates that such probiotic property is strain-specific and gives evidence of potential application in minimally-processed foods subjected to moderate heat processing.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author