Characterization and antifungal activity against Pestalotiopsis of a fusaricidin-type compound produced by Paenibacillus polymyxa Y-1

Dendrobium nobile (D. nobile) is a valuable Chinese herbal medicine. The discovery of microbial resources from has provided a wealth of raw materials. Stalk rot, which is caused by Pestalotiopsis, is one of the most serious diseases of D nobile and has resulted in serious losses in production. However, an effective method for the prevention and control of stalk rot remains lacking. In this study, we aimed to identify a biocontrol strain against Pestalotiopsis. We isolated Paenibacillus polymyxa Y-1, an endophytic bacterium, from the stem of D. nobile. Three pairs of active metabolites isolated from this bacterium were identified as fusaricidin compounds. We then investigated the mechanism of fusaricidin compounds on Pestalotiopsis via proteomics. Proteomics data showed that the compounds mainly inhibit energy generation in the respiratory chain and amino acid biosynthesis of Pestalotiopsis. In this study, an endophytic bacterium was isolated from the stem of Dendrobium nobile and identified as Paenibacillus polymyxa Y-1. The active metabolites of this bacterium were isolated and identified as fusaricidin compounds. The mechanism of fusaricidin compounds on pathogenic fungi (Pestalotiopsis) was investigated by using proteomics. [Display omitted] •Isolated and identified an endophytic bacterium isolated from Dendrobium nobile is Paenibacillus polymyxa Y-1.•The active metabolites of P. polymyxa Y-1 were identified as fusaricidin compounds.•The mechanism of the fusaricidin compounds against pathogenic fungi was investigated via proteomics.•The compounds affect DNA transcription, energy metabolism, and amino acid synthesis.