Evaluation of a Natural Food Preservative Bac...

Evaluation of a Natural Food Preservative Bacteriocin Isolated from Lactic Acid Bacteria (Lab) a Potent Source

Author Name : Mr. Sandeep Nikam, Pradum Shinde, Dr. Sneha Agrawal

ABSTRACT LAB bacteriocins is being regarded by many experts as the upcoming discipline in food bio-preservation. It constitutes a ‘safer’ and ‘natural’ alternative solution to the problems caused by the ‘artificial’ preservative approaches used today. These are ribosomal synthesized antimicrobial peptides produced by Lactic acid bacteria, that are released extracellularly and have an antagonistic mode of action against susceptible target organisms. Due to their potent activity and ability to tolerate extreme temperatures and pH conditions, these antimicrobial peptides now prospect to be employed in Food technology as biological-based food preservatives with an ability to potentially eliminate food spoilage-causing pathogens. The study underlying this thesis was aimed at checking the antimicrobial activity of Bacteriocins produced by four Lactobacillus isolates, procured from various dairy and fermented food sources, against four indicators viz., two Gram-positive, i.e., Staphylococcus aureus, Bacillus subtilis, and two Gramnegative, i.e., Escherichia coli and Pseudomonas aeruginosa. A broth fermentation of each of the isolates was carried out in MRS Broth under anaerobic conditions for 3 days, followed by the preparation of Cell-free supernatants (CFS). These CFS thus prepared were filtered sterilized, neutralized, and checked for their antimicrobial against the four indicators by Agar-well diffusion (AWD) assay. For all four isolates, no zone of inhibition against any of the indicators was produced, which suggests that the Lactobacillus isolates were not Bacteriocins producers. Keywords: Antimicrobial, Bio preservatives, Food Preservation, Lactic acid bacteria, LAB Bacteriocins