Lipopeptides from Antarctic Bacillus siamensis N52R1 inhibit Pseudomonas aeruginosa biofilm.

This article focuses on the identification of bioactive compounds produced by Antarctic microorganisms, specifically Bacillus siamensis strain N52R1, that inhibit biofilm formation by the pathogenic bacterium Pseudomonas aeruginosa. Through cultivation and extraction of bacterial secretomes, the study found that polar hexane fractions from N52R1 significantly reduced P. aeruginosa biofilms without affecting bacterial growth. Untargeted metabolomics and molecular networking analyses suggest that lipopeptides, particularly plipastatin and surfactin, are responsible for this antibiofilm activity, marking a novel report of their effect on P. aeruginosa. Toxicity assays using Galleria mellonella larvae indicated that the active fractions are non-toxic at concentrations up to 200 mg/kg, supporting their potential for further development as antivirulence agents against biofilm-associated infections.