Antibacterial activity of lactic acid bacteria isolated from fresh pepper and tomatoes against common food pathogens

Abstract

This study aimed to investigate the antibacterial activity of lactic acid bacteria (LAB) isolated from fresh pepper and tomatoes against common food borne pathogens. Man Rogosa Sharpe (MRS) broth and agar were used for the isolation of LAB from the food products and whose antagonistic properties were tested against Bacillus cereus, Staphylococcus aureus, Streptococcus sp., E. coli, Klebsiella pneumoniae and Pseudomonas aeruginosa using well diffusion assay method. Four LAB species were isolated and these included Streptococcus pyogenes, Enterococcus faecalis, Lactococcus casei and Lactococcus fermentii. The percentage occurrence of LAB species ranged from 11.77% to 35.29%. E. faecalis exerted the strongest antibacterial activity against all selected pathogenic bacteria while L. casei showed the weakest activity. It was concluded that the isolated LAB showed remarkable inhibitory effect against tested pathogenic strains. It is therefore suggested that these potent isolates could be used as a natural bio-preservatives in different food products. However, further in vitro and in vivo studies are required, according to selection criteria, on their application in different food products.