Evaluation of Bacillus velezensis NKG-2 for Bio-control Activities Against Fungal Diseases and Potential Plant Growth

This study investigated the antifungal metabolites of Bacillus velezensis NKG-2, a bacterium isolated from the Qilian Mountains in China’s Qinghai Province. Experimental results showed this bacterium exhibited antagonistic activity against major plant fungal pathogens, namely Fusarium oxysporum, Fusarium graminearum, Botrytis cinerea, Alternaria alternata, Fulvia fulva, and Ustilaginoidea virens. In addition, the volatile organic compounds (VOCs) produced by Bacillus velezensis NKG-2 adversely affected the growth of these fungi. We also found that B. velezensis NKG-2 produced chitinase, cellulase, β-glucanase, and amylase enzymes and it promoted tomato plant growth as well, by producing indole-3-acetic acid (IAA) and siderophore. From in vivo biocontrol assay, tomato (Solanum lycopersicum L.) plants treated only with plant pathogenic fungi showed a disease severity of 65%, whereas bacterial-treated plants lacked any symptoms and their disease severity was only about 25% at the final sampling time. This comprehensive study explored and analyzed many benefits of B. velezensis NKG-2 for its use as a potential biocontrol agent and plant growth promoter, which could be used for improving economic and agricultural development.
Source: Biological Control - Category: Biology Source Type: research