Partial purification and characterization of a bacteriocin produced by Lactobacillus acidophilus

Abstract

Bacteriocin produced by Lactobacillus acidophilus was partially purified by ammonium sulfate precipitation 60% saturation. The bacteriocin exhibited activity of 320AU/ml against Serratia marcescens. Characterization of bacteriocin showed that its active principle was proteinaceous in nature since it was inactivated by proteolytic enzymes but not by other enzymes. Treatment of bacteriocin with organic solvents 5% concentration did not affect the activity of it, but its activity was reduced to the half at 10% concentration of the solvents. Bacteriocin activity was stable at pH 4 -7, half of its activity was lost at pH8, and whole activity was lost at other pH values. Bacteriocin was stable at 40-100°C for 10min, but it retained only 50% of its activity at 40 and 60°C for 30min. whole activity was lost at 80 and 100°C for 30min and at 121°C for 15 min.