Isolation and screening of bacteriocin-producing bacteria from native dairy products of Kerman province and study of antibacterial activity of produced bacteriocin

In recent years, Bacteriocins have been recognized as natural preservatives in food and drug industries, also, nowadays, they are used as substitutes of chemical antibiotics for treatment of infections. Bacteria in probiotic dairies recognized as “Lactic Acid Bacteria”, are significant group of bacteriocin producing bacteria. In this study 15 isolates have been isolated from native dairies of Kerman province. The Bacteriocins were purified by sulfate ammonium method. The effect of produced bacteriocins on different indicator gram negative and positive strains was investigated. The effects of trypsin, pH ranges, and heat on the produced bacteriocin were investigated too. The isolate that produced the most bacteriocin with the most antibacterial activity, identified as Enterococcus faecium Y1.The maximum antibacterial effect was observed against Listeria monocytogenes and Pseudomonas aeruginosa. The produced bacteriocin lost activity in presence of trypsin. It was resistant against pH ranges from 2 to 12 and heat ranges up to autoclave temperature. The produced bacteriocin had a wide antibacterial activity spectrum against the gram positive and negative bacteria, in particular pathogenic bacteria, also was resistant against heat and pH ranges. As a result, use of bacteriocin in food and drug industry, as animal feed, and as a substitute for chemical antibiotics is recommended.