Antifungal effect of antimicrobial peptides (AMPs LR14) derived from Lactobacillus plantarum strain LR/14 and their applications in prevention of grain spoilage.

The concern for food safety has led to an increased interest in the development of novel antimicrobials. Keeping this aim in mind, we have investigated the antifungal effect of antimicrobial peptides (AMPs LR14) produced by Lactobacillus plantarum strain LR/14 against four spoilage fungi, namely, Aspergillus niger, Rhizopus stolonifer, Mucor racemosus and Penicillium chrysogenum. Interestingly, all the four fungi were inhibited, suggesting that AMPs LR14 exhibited anti-fungal property. The peptides inhibited both, the spore germination and hyphal growth, however, the former stage was found to be more susceptible. The hyphal extensions were also inhibited in a dose-dependent manner. Viability test of treated spores confirmed the fungicidal activity of AMPs LR14. AMPs LR14 were also studied for the prevention of wheat grain spoilage under storage. Unhygienic conditions in damp godowns and store-houses, lead to loss of food grains and make them unfit for human consumption due to microbial deterioration. The treatment of wheat seeds with AMPs LR14 prevented fungal growth even after a prolonged storage under laboratory conditions for ∼2.5 years. The carbohydrate and protein content of the AMPs LR14-treated seeds denoted no significant loss, but the seed viability was affected as germination was retarded. Such studies have not been reported for any bacteriocin/AMP to the best of our knowledge.