Isolation and NMR Analysis of Antifungal Fengycin A and B from Bacillus amyloliquefaciens subsp plantarum BC32-1

Natural antibiotics produced by microorganisms have generated considerable interest in various industries. Here we report the potential of antifungal lipopeptides produced by Bacillus amyloliquefaciens subsp. plantarum BC32-1 isolated from ultisols. The BC32-1 strain strongly inhibited mycelial growth of plant pathogenic fungi. Several lipopeptides were purified by organic solvent extraction and reversed-phase high-performance liquid chromatography (RP-HPLC). The purified lipopeptides contained iturin, fengycin, and surfactin-type lipopeptides, as confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses. Since fengycin-type lipopeptides showed strong antifungal activity, we characterized the chemical structures of fengycin A and B using LC-MS/MS and 2D NMR spectroscopy. This study will provide the structural basis for the development of new antifungal agents for the control of pathogenic fungal diseases.