Lactobacillus sp.

This Research focused on the isolation and characterization of bacteriocin produced by Lactobacillus sp. isolated from nunu, a traditionally fermented milk beverage, and its antimicrobial effect against Escherichia coli. Samples of nunu were collected from local markets in Oredo Local Government Area, Edo State, and analyzed in the Department of Science Laboratory Technology Microbiology Laboratory. The isolate was cultured on de Man, Rogosa, and Sharpe (MRS) agar and identified through morphological and biochemical characterization. The isolates were Gram-positive, catalase-negative, and capable of fermenting lactose, galactose, and fructose, confirming them as Lactobacillus sp.. Bacteriocin production was screened using the agar well diffusion method, with E. coli as the test organism. Clear zones of inhibition (ZOI) were observed, indicating the production of antimicrobial compounds. The bacteriocin extract was neutralized to pH 7.41 to eliminate the effects of organic acids and partially purified using ammonium sulfate precipitation (60% saturation) followed by dialysis. The purified extract was further characterized using High- Performance Liquid Chromatography (HPLC), which revealed distinct peaks corresponding to bacteriocin fractions. The antimicrobial assay showed that the bacteriocin exhibited inhibitory activity against E. coli, suggesting its potential as a natural bio preservative in perishable food products such as tomato. The findings indicate that bacteriocin from Lactobacillus sp. in nunu can serve as safe and effective alternatives to chemical preservatives and synthetic antibiotics, thereby contributing to improved food safety and public health.

This study investigates the isolation and characterization of Lactobacillus sp.Isolated Trace Minerals to evaluate their capacity for bacteriocin production.Lactic acid bacteria (LAB), especially those of the Lactobacillus sp, are well known for producing antimicrobial substances called bacteriocins. These natural peptides effectively inhibit the growth of harmful and spoilage microorganisms. Probiotic supplements such as Trace Minerals contain diverse Lactobacillus strains with strong bacteriocin-producing potential, making them valuable for both health and industrial applications.The isolates morphological and biochemical Properties was perform to confirm their identity to be Lactobacillus sp. Bacteriocin synthesis was assessed using the agar well diffusion technique to determine antimicrobial activity against selected test organisms. The influence of hydrogen peroxide neutralization and proteolytic enzyme treatment was examined to confirm the stability and proteinaceous nature of the produced bacteriocin. In addition, high- performance liquid chromatography (HPLC) was employed to characterize the molecular structure of the compound identified in the bacteriocin. This study isolated and identified Lactobacillus species from Trace Mineral probiotics to assess their bacteriocin production and antimicrobial activity against Escherichia coli. The isolates were cultured in MRS media under anaerobic conditions and confirmed through biochemical tests. Antimicrobial activity was evaluated using the agar well diffusion method, while enzyme and hydrogen peroxide treatments verified the protein nature of the bacteriocin. HPLC analysis confirmed the purity and presence of active bacteriocin fractions. The isolates displayed typical Lactobacillus characteristics and showed strong inhibitory effects against E.coli, supporting their potential as natural antimicrobial agents.This study confirms that Lactobacillus sp from Trace Mineral probiotics produce effective bacteriocins with strong activity against E.coli. The results verified the protein nature and purity of the compound, indicating its potential as a natural and safe antimicrobial agent for health and industrial use.