LAUSR

BACKGROUND Lipopeptides from the Bacillus spp. possess excellent spectrum of antimicrobial properties which make them suitable candidates to be explored for the food, agricultural, pharmaceutical and biotechnological applications. As the low yield of the lipopeptides limits their applications, methods to enhance its production are highly significant. RESULTS In the study, the extracts prepared from the endophytic Bacillus sp. Fcl1 cultured in presence of various supplements were screened for the antifungal activity against Pythium aphanidermatum. From the results, the supplementation of carbon sources and zinc oxide nanoparticles (ZnONPs) was found to have enhancement effect on the antifungal activity of Bacillus sp. Fcl1. Among these, the highest antifungal activity (73.2 %) could be observed for the Fcl1 sample cultured with 5 mg/L of ZnONPs supplementation. The growth of Fcl1 in the presence of ZnONPs also indicated its compatibility to the nano-supplement at the used concentration range. By the LC-QTOF-MS analysis, the synthesis of increased numbers of lipopeptide surfactin derivatives could be identified from the extracts of Fcl1 prepared from the carbon sources and ZnONPs supplemented cultures. In addition to the surfactin derivatives, the presence of another lipopeptide iturin was also detected from the extracts of Fcl1 cultured with ZnONPs. CONCLUSION From the results of the study, the ZnONPs supplementation was found to enhance the antifungal activity and lipopeptide production in the Bacillus sp. Fcl1. The use of nanoparticles to enhance the antifungal mechanisms of Fcl1 as observed in the study provides novel insights to explore its applications for sustainable agricultural productivity. This article is protected by copyright. All rights reserved.