Аннотация
Pear fire blight caused by Erwinia amylovora necessitates environmentally friendly biocontrol alternatives. Strain TRMB57781, isolated from Alar chemical plant wastewater, was identified as Paenibacillus sp. via polyphasic taxonomy and 16S rRNA gene analysis. Whole-genome sequencing revealed a biosynthetic gene cluster for fusaricidin B. Fermentation medium optimization with glucose and cottonseed meal significantly enhanced antibacterial activity. In vitro assays demonstrated that a 1:50 dilution of the fermentation broth achieved 84.62% control efficacy on fragrant pear inflorescences, markedly exceeding agricultural streptomycin (69.48%). Comparable efficacy to streptomycin was observed in detached leaf assays and potted plant protective and curative trials. Through HR-TOF MS analysis combined with genomic verification, the active compound was identified as a key antimicrobial metabolite associated with the antagonism against E. amylovora. This study presents Paenibacillus sp. TRMB57781 as a promising biocontrol agent and provides genomic and metabolomic insights into its antibacterial activity against pear fire blight.