Purification and Mode of Action of Antilisterial Bacteriocins Produced byLactobacillus pentosus SJ65 Isolated fromUttapamBatter

Abstract

Humans and lactic acid bacteria (LAB) have allied relationships for thousands of years, where LAB has been involved in food preservations as well as in preserving human health against several pathogens. This study aims at partial purification of bacteriocins from Lactobacillus pentosus SJ65 isolated from fermented Uttapam batter, a South Indian fermented food source, their characterization and mode of action. The bacteriocin was purified using various strategies such as acetone precipitation, gel permeation and hydrophobic interaction chromatography. The bacteriocin was stable at acidic and neutral pH and up to 100C and exhibited a wide spectrum of activity against clinically relevant gram-positive and gram-negative pathogens. However, Tris-tricine sodium dodecyl sulfate, native polyacrylamide gel electrophoresis and its gel half activity assay against Listeria monocytogenes showed that the purified bacteriocin is composed of two independent peptides with molecular weight of 3.9 and 1.6 kDa. Practical Applications Bacteriocins, proteinaceous antimicrobial compounds from lactic acid bacteria, are receiving attention for their contribution in food preservation. In addition, interests are created for their use against human bacterial, fungal infections and cancer treatment. To date, only nisin and pediocin have been approved by the United States Food and Drug Administration for use in food industries as preservatives and marketed worldwide. Other bacteriocins such as lactacins, plantaricins, pentocins, etc., are in their own lines of progress for several applications. Bacteriocins are advantageous being less toxic, having broad spectrum of activity and exhibiting antimicrobial activity at nanomolar concentrations. Thus, bacteriocins can be a potential drug candidate for replacing antibiotics to treat drug-resistant pathogens in the future.