Effect of bacteriocins from lactic acid bacteria obtained from Zea mays-based Ogi on foodborne bacteria from contaminated cabbage

Abstract

The objective of this work was to evaluate the effect of bacteriocins from lactic acid bacteria (LAB) in Zea mays-based Ogi on some foodborne bacteria contaminating cabbage in Abakaliki, Nigeria. Ten (10) samples (5 samples of Z. mays-based Ogi and 5 samples of suspected contaminated cabbage heads) were aseptically collected and analyzed using standard microbiological methods. Five different Lactobacillus isolates (A, B, C, D, and E) were isolated from the Z. mays-based Ogi while 5 different species of bacterial pathogens; Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella spp., and Shigella spp were isolated from cabbage heads. Results showed that Lactobacillus isolates exhibited high inhibitory effect against foodborne bacteria (S. aureus, E. coli, and Shigella spp) isolated from cabbage with inhibition zone diameter (IZD) ranging from 14 to 20 mm. A very high antimicrobial activity against foodborne bacteria isolated from cabbage was also observed for the crude bacteriocin at pH of 2. The stability of the antimicrobial affinity of the bacteriocin decreased as pH rises from 6 to 7. This study has shown that bacteriocin has antimicrobial activity against foodborne bacteria contaminating cabbage and could be used as bio-preservatives instead of hazardous chemical preservatives with adverse effects on the human body.   Key words: Lactic acid bacteria, bacteriocin, Zea mays, cabbage, fermented food, Ogi.