Antimicrobial compound produced by human gut lactic acid bacteria having antifungal activity against aflatoxigenic Aspergillus flavus MTCC 2798

Abstract

Lactic acid bacteria (LAB) are a group of distinguished bacteria that have reserved their place in the food industry, with their probiotic properties as well as their ability to produce many antimicrobial compounds. The antagonistic microorganisms and their bioactive compounds have a potential application as natural bio preservatives as they not only inactivate but also inhibit the growth of undesired microorganisms in food. Hence, the use of LAB and their antimicrobial compounds like organic acids, hydrogen peroxide, diacetyl, bacteriocins, etc. attract considerable interest during the past years. Among the 173 human gut LAB studied 17 isolates showed antifungal activity against aflatoxigenic Aspergillus flavus MTCC 2798. All the seventeen isolates produced antimicrobial compounds such as lactic acid, hydrogen peroxide, diacetyl. GC–MS based metabolic profiling of the methanolic extracts of 17 isolates identified 40 metabolites. Thirteen metabolites were identified and reported to have potent antimicrobial activity. The results suggest the antagonistic potential of antimicrobial compounds produced by human gut LAB having significant application in the pharmaceutical and food industry. Novelty impact statement Antimocrobial compounds were produced by seventeen antifungal human gut Lactic acid bacteria have promising application as food preservative. GC–MS based metabolic profiling of the methanolic extracts of 17 isolates identified thirteen metabolites reported to have potent antimicrobial activity. Bioactive metabolite Cyclo(leucyl prolyl), was present in the methonolic extract of all the seventeen LAB isolates reported to have anti-aflatoxin activity, thus confirms the anti-aflatoxigenic property of the isolates.