C_(17)-fengycin B,produced by deep-sea-derived Bacillus subtilis,possessing a strong antifungal activity against Fusarium solani

Root rot disease caused by Fusarium solani is the most devastating disease of the tomato and legume crops in China.The metabolites of Bacillus species can inhibit many fungal diseases.In this study,the metabolites of deep-sea-derived bacterium Bacillus subtilis 2 H11 can significantly inhibit the growth of F.solani.The metabolite C_(17)-fengycin B,one of the cyclic lipopeptides,was identified by the combination of silica column chromatography,high-performance liquid chromatography(HPLC),high-energy collision induced dissociation mass spectrometry(HCD-MS) and tandem mass spectrometry(HCD-MS/MS).The results of scanning electron microscopy(SEM) and transmission electron microscopy(TEM) showed that C_(17)-fengycin B could destroy the structure of the hyphae and spores of F.solani.The antifungal activities of C_(17)-fengycin B against F.solani were tested at concentrations ranging from 0.05 mg/mL to 0.20 mg/mL.The results indicated that C_(17)-fengycin B inhibited the growth of F.solani with antifungal index of 89.80%at 0.20 mg/mL,and the antifungal activity of C_(17)-fengycin B was further verified by the pot experiment.In addition,the cytotoxicity experiment showed that C_(17)-fengycin B had good biocompatibility and was a potential candidate for the development of biocontrol pesticide in the future.