Pseudophomins A-D Produced from sp. HN8-3 Using an OSMAC Approach and Their Roles in Biocontrol of in Cucumbers.

In this study, two new cyclic lipopeptides (CLPs) pseudophomins C () and D () and two known CLPs pseudophomins A () and B () were produced and characterized from the bacterial supernatant of sp. HN8-3 by an OSMAC (one strain-many compounds) approach. OSMAC is a strategy that involves feeding of a single microorganism with divergent substrates to stimulate the production of new secondary metabolites. These pseudophomins were purified and identified via chromatographic methods, droplet collapse assay, genome mining, spectroscopic and spectrometric analyses, and single-crystal X-ray diffraction (XRD). Moreover, bioactivity tests showed that pseudophomins could lyse the zoospores of in vitro, and coapplication of pseudophomins with zoospores of further reduced the incidence of on cucumber leaves. Collectively, these results indicated that pseudophomins have the potential to be developed as biopesticides for controlling in cucumber.