Antibacterial activity and mechanism of Myxin from Lysobacter antibioticus against Xanthomonas fragariae

Abstract

BACKGROUNDXanthomonas fragariae (Xaf), the causative agent of angular leaf spot (ALS) in strawberries, poses a significant threat to the strawberry industry due to the current lack of effective biological control measures. Myxin, produced by Lysobacter antibioticus, exhibits good inhibitory activity against various pathogenic bacteria. However, the efficacy and mechanism of its antibacterial actions against X. fragariae remains poorly understood.RESULTSX. fragariae proliferation was almost completely suppressed by Myxin at 0.6 MIC (Minimum Inhibitory Concentration, MIC = 40 μg/mL). Biological characterization experiments found that Myxin can change the permeability of Xaf cell membrane, induce cell swelling, accumulate intracellular reactive oxygen species (ROS), hinder the synthesis of biofilm, Exopolysaccharide (EPS) and intracellular protein. Significant findings revealed a notable decrease in the expression of genes associated with ribosome metabolism, amino acid production, and energy metabolism, while genes related to oxidative stress were upregulated, and there was a change in the expression of genes involved in cell structure and exopolysaccharide biosynthesis.CONCLUSIONThis study reveals that the Myxin employs a multi‐target antimicrobial strategy against X. fragariae. Our findings lay the groundwork for using Myxin and developing a disease management system for strawberry angular leaf spot. © 2025 Society of Chemical Industry.