Identification of potential probiotic Lactobacillus plantarum isolates with broad-spectrum antibacterialactivity
Food deterioration is largely related to contamination by undesirable microorganisms; it can cause economical loss and serious health-related problems. Owing to increased awareness of health issues by consumers, biological food preservation using antibacterial Lactobacillus species is being increasingly studied. Here, we make a preliminarily assessment of the antibacterial activity of 347 Lactobacillus plantarum isolates against five common food-borne pathogens (Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Salmonella typhimurium, and Shigella flexneri). Nine of these isolates had broad-spectrum antibacterial activity and were selected for further experimentation. Subsequent assays based on physical, chemical, and sensory evaluations of yoghurts fermented in the presence or absence of each of the selected isolates and persistence of antibacterial activity following protease challenge revealed that L. plantarum isolate IMAU10216 was superior to the other isolates. L. plantarum IMAU10216 also exhibited high in vitro gastrointestinal tract tolerance. To conclude, we have identified a novel bioactive antibacterial L. plantarum isolate with potential for use as a probiotic in the production of fermented milk or other related dairy products. Further in vivo studies are now required.