Antagonistic effect of bacteriocin from Bacillus subtilis against food-borne pathogens
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Abstract
Preservation of food items through natural and biological methods has become a norm in order to prevent huge financial losses that may be incurred as a result of contamination of raw foods and/or food products. Biological preservation methods help avert the chances of food born ailments thus ensuring the fulfillment of ever-increasing global food requirements. Growing skepticism among the customers in recent years regarding food safety and preservatives used in food industry has fetched remarkable consideration to the use of Bacillus bacteriocin in food processing as well as human health care. Bacillus subtilis was isolated from soil samples for determination of its microscopic and biochemical characteristics. The proteinaceous antimicrobial compounds were extracted through ammonium sulfate precipitation method. The bacteriocin was partially purified through SDS-PAGE; optimization of bacteriocin at different pH levels, heating temperatures and storage conditions was performed. Indicator strains were procured from CMS, UAF, Faisalabad. The antimicrobial assays of extracted bacteriocin were determined on Mueller-Hinton media through agar well diffusion method. The extracted bacteriocin showed comparatively better antibacterial activity against indicator Staphylococcus aureus followed by E. coli and Salmonella. Maximum activity was observed at pH 7, heating temperature 37°C and storage 4°C, comparatively higher activity against Gram positive bacteria was noticed.
Keywords: Biological preservation; Economic losses; Antimicrobial compounds; Optimization