Broad‐spectrum antifungal activity of lipopeptide brevilaterin B and its inhibition effects against Fusarium oxysporum and Penicillium chrysogenum.

Aims: Brevilaterin B is a natural antimicrobial lipopeptide produced by Brevibacillus laterosporus S62‐9. However, its antifungal spectrum and modes of action are still unclear. Herein, we investigated the detailed antifungal activity of brevilaterin B against 33 pathogenic fungi and the antifungal effects against two sensitive fungi in vitro and in vivo. Methods and Results: Brevilaterin B exhibited inhibitory activity against 33 pathogenic fungi involved in plant disease and food spoilage at the minimum inhibitory concentrations (MICs) range of 16–128 μg ml−1. The antifungal effects were further studied by Fusarium oxysporum and Penicillium chrysogenum. Both spore germination and mycelium growth were inhibited by brevilaterin B at sub‐MIC. Transmission electron microscopy and fluorescent dye staining assays indicated brevilaterin B damaged cell integrity and induced apoptosis. In vivo tests, brevilaterin B inhibited the infection of F. oxysporum to Dendrobium officinale and P. chrysogenum to mandarin (Citrus reticulata) at 500 μg ml−1, respectively. Conclusions: Brevilaterin B showed broad‐spectrum antifungal activity against 33 pathogenic fungi. And its antifungal modes of action were proposed as damaging cell integrity and inducing cell apoptosis. The lipopeptide is promising to control F. oxysporum in the D. officinale and P. chrysogenum in the mandarin. Significance and Impact of Study: The research provided insights into antifungal modes of action of brevilaterin B. The lipopeptide brevilaterin B is potential to be developed as a broad‐spectrum antifungal agent for agricultural biocontrol and postharvest storage. [ABSTRACT FROM AUTHOR]