Bacteriocinogenic Activity of Lysinibacillus fusiformis NR_042072.1 Isolated from Cow Milk

Abstract

The prevailing increase in the search for bio-preservatives in the food industry has raised global concern. Biological substances with health benefits and no toxicity are considered as alternatives to the chemicals in food processing. Bacteriocins, which are proteinaceous substances with preservative properties, are now gaining attention in this regard and the search for new organisms for production is becoming global. This study focuses on the analysis of bacteriocinogenic activity of a local strain of Lysinibacillus fusiformis NR_042072.1 isolated from fresh cow milk obtained from Gaa Mobolohunduro, Tanke, Ilorin, Kwara State, Nigeria. Lactic acid bacteria were isolated from cow milk, characterized and identified using standard microbiological methods. Bacteriocin was extracted from the isolate, partially purified, and characterized using standard methods; and the antibacterial activity against some foodborne bacteria which are Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus subtilis was determined using agar-well diffusion method. The effect of certain physicochemical parameters on the antibacterial activity of the bacteriocin was also determined. The isolate was identified as Lysinibacillus fusiformis NR_042072.1. The bacteriocin showed antibacterial action against E. coli and P. aeruginosa with a zone of inhibition of 17.0±0.5 and 20.0±1.0 mm, respectively. The bacteriocin was active within temperatures of 4-50 °C, pH 5-7.5, bile salts concentration of 0.6-1.0 % and in the presence of the enzymes trypsin and pepsin. In conclusion, the bacteriocin produced by Lysinibacillus fusiformis NR_042072.1 could control food spoilage caused by the test organisms.