Bacteriocin production and characterization from lactic acid bacteria

A variety of bacteriocins, produced by bacteria that kill or inhibit the growth of other bacteria, have been identified and characterized biochemically and genetically. Lactic acid species were isolated from indigenious dairy source and purified using different microbiological techniques. The pure culture was maintained in selective broth and used for bacteriocin production. The produced bacteriocin was concentrated and characterized heating up to 100 C was found to have less effect while more heating minimized the bacteriocin activity. Similarly at low pH, activity of bacteriocin reduced while at higher (6.8), near to neutral, it showed higher antimicrobial activity. On treating with choloroform, bacteriocin activity ceased while NaCl concentration, up to 4% had no effect bacteriocin production. The selected extract was partially purified by ammonium sulphate at 80% saturation level and then further purified by using gel filtration chromatography using Sephadex-100. Most of the extract exhibited anti-bacterial activity against bacterial strain. It is suggested that LAB is a source far anti-bacterial peptides and in future, may be used for industrial extraction and isolation.