Antimicrobial Activity of Lactobacillus from Zobo Drink Against Various Pathogens

Abstract

Background and Objective: The bio-preservation of food products using bacteriocin-producing lactic acid bacteria (BPLAB) isolated directly from fermented foods is an innovative approach in ensuring food safety for human health sustainably. This study was designed to isolate and identify BPLAB from zobo drinks and evaluate their antimicrobial effects on selected spoilage and pathogenic microorganisms in vitro. Materials and Methods: Lactic acid bacteria were isolated using bacteriological media, while agar diffusion bioassay was employed to screen bacteriocin or bacteriocin-like substances and their antimicrobial effect was tested on selected pathogens, namely Salmonella pullorum, Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli as indicator organisms. Results: A high pH value of 5.5 was recorded from the control sample (LAB) while high temperature and total titratable acid of 28EC and 0.62% were obtained from the ETF sample, respectively. Out of 14 lactic acid bacterial isolates, Lactobacillus minor and L. buchneri exhibited total inhibition while L. bifermentans and L. fructivorans exhibited no inhibition to the tested microorganisms. Varied antimicrobial susceptibility profiling for the indicator isolates was recorded. Conclusions: The potential of BPLAB to inhibit some pathogens suggest their potential use as bio-preservatives in foods. Hence, this study was performed to test for the antimicrobial ability of Lactobacillus isolated from zobo drinks against some selected pathogens.