Probiotic Properties of Enterococcus Isolated From Artisanal Dairy Products

Abstract

The present study focused on probiotic characterization and safety evaluation of Enterococcus bacteria from different artisanal dairy products. Morphological properties, acid and bile tolerance, antimicrobial activities, PCR amplification of known enterocin genes, exopolysaccharide production, auto-aggregation, co-aggregation, cell surface hydrophobicity, adhesion to human intestinal cells, cholesterol removing ability, hemolytic and β-galactosidase activities, bile salt hydrolysis, resistance to antibiotics and detection of virulence factors were evaluated. All the isolates exhibited inhibitory activity against several food spoilage bacteria and food-borne pathogens, including Shigella flexneri, Staphylococcus aureus, Listeria monocytogenes, Yersinia enterocolitica, Klebsiella pneumoniae, Escherichia coli and Bacillus subtilis. The Enterococcus isolates showed cholesterol lowering and pathogen inhibition properties. Hydrophobicity and auto-aggregation results indicated strong attachment capacity of the isolates. The PCR results indicated the presence of at least one enterocin structural gene in all the tested strains. The Enterococcus isolates were further evaluated regarding their safety properties and functional features. The isolates were susceptible to vancomycin, gentamycin and chloramphenicol. The results of PCR amplification revealed that all the tested isolates harbored none of the tested virulence genes. This study revealed that the Enterococcus isolates, especially E. durans ES11, ES20 and ES32, might be excellent candidates for production of functional foods to promote health benefits.