Biocontrol potential of Bacillus amyloliquefaciens D5 ARV metabolites

Integrated pathogen management incorporates biological control and ecological services of plant growth-promoting bacteria as base components. The biocontrol activity of Bacillus amyloliquefaciens D5 ARV toward Fusarium oxysporum, Fusarium graminearum, Botrytis cinerea, and Macrophomina sp. was estimated through a confrontation test, and the potential of volatile and non-volatile organic compounds (VOCs). The results of the confrontation test showed 60, 46, 37, and 33% of F. oxysporum, F. graminearum, B. cinerea, and Macrophomina sp. growth inhibition, while VOCs effects reached 30%, 47%, 53%, and 0% growth inhibition, respectively. A collection of non-volatile metabolites was made at a stationary phase; afterward, they were sterilized by filtration or autoclaving. Autoclaving caused a significant loss of non-volatile metabolite antifungal activity. GC-MS analysis of VOCs detected the presence of compounds with antifungal and antimicrobial properties such as pentadecanoic acid, and hexanedioic acid, bis(2-ethylhexyl) ester. The multiple antifungal mechanisms revealed in this study are part of the B. amyloliquefaciens D5 ARV arsenal and make it a potentially powerful biocontrol agent against selected phytopathogens.