In this study, Bacillus velesensis TJS119, isolated from freshwater, demonstrated growth inhibition against insect pathogenic fungi. The culture medium of the B. velezensis TJS119 strain underwent sequential fractionation with n-hexane, chloroform, ethyl acetate, n-butanol, and water. Notably, the n-butanol fraction exhibited significant antifungal activity against Metarhizium anisopliae and Beauveria bassiana. LC/MS analysis of antifungal peaks identified the production of various lipopeptides by B. velezensis TJS119, including two types of iturin A (C14, C15), four types of fengycin A (C14, C15, C16, C17), and two types of fengycin B (C16, C17). The antifungal efficacy of Iturin A and Fengycin against insect pathogenic fungi was further validated using the paper disc diffusion method. These findings underscore the potential of B. velezensis TJS119 as a promising candidate for future research and applications in the realm of agricultural biological controls against fungal diseases.

• Young Ho Nam(Microbial Research Department, Nakdonggang National Institute of Biological Resources (NNIBR), Republic of Korea) Corresponding author
• Buyng Su Hwang(Bio-Resource Industrialization Center, Nakdonggang National Institute of Biological Resources (NNIBR), Republic of Korea)
• Kook-Il Han(Microbial Research Department, Nakdonggang National Institute of Biological Resources (NNIBR), Republic of Korea)
• Jeomok Jung(Microbial Research Department, Nakdonggang National Institute of Biological Resources (NNIBR), Republic of Korea)
• Eunsun Kim(Industrial Insect and Sericulture Division, National Institute of Agricultural Sciences, RDA, Jeonju, Republic of Korea)
• Mi-Hwa Lee(Microbial Research Department, Nakdonggang National Institute of Biological Resources (NNIBR), Republic of Korea)