MOLECULAR SEPARATION, PROBIOTIC PROPERTIES AND ANTILISTRIOSTIC BACTERIOCIN PRODUCTION OF ENTEROCOCCUS FAECIUM AND LACTOBACILLUS CURVATUS

Background and Aim:Bacteriocins have become important preservatives in the food and pharmaceutical industries and today they become important substitutes for chemical antibiotics . The purpose of this study is isolation and molecular identification of Enterococci and Lictobacilli producing bacteriocins with a wide range of antibacterial activity. Enterococcus facium strain had the most antibacterial effect against Listeria monocytogenes 506 and Lictobacillus brevis F 145 and has both bactericidal and Bacteriostatic properties , whereas the lactobacillus curvatus strain had bacteriostatic properties. Bacteriocin lost activiry in presence of trypsin and proteolytic enzymes and maintained its activity against pH changes from 3 to 10 and changes in temperature to 121 Co. The bacteriocin genes of Enterococcus faecium and lactobacillus curvatus ent A, ent P, but L50A and curA were 135, 216 and 542 bp, respectively. The probiotic properties of strains were able to grow in the acidic range and in the presence of bile salts.Methods:Among the isolated bacteria, two strains with the ability to produce bacteriocin more than other samples were selected for sequencing. DNA extraction was performed based on the kit. PCR reaction was performed using primers of 16S rRNA and PCR products were sequenced after purification.Results:Identified isolates under the name Lactobacillus curvatus and Enterococcus faecium.Conclusion:Use as a bio-maintainer in the food industry, Pharmaceuticals and animal feed, as well as an alternative to chemical antibiotics .

Keywords:

Bacteriosin , Enterococcus , Lactobacillus , listeriosis , Bactericidal , Bacteriostatic , Probiotic properties