Glycosyl hydrolase from Pseudomonas fluorescens inhibits the biofilm formation of Pseudomonads

Biofilms are complex microbial communities embedded in extracellular matrix. Pathogens within the biofilm become more resistant to the antibiotics than planktonic counterparts. Novel strategies are required to encounter biofilms. Exopolysaccharides are one of the major components of biofilm matrix and play a vital role in biofilm architecture. In previous studies, a glycosyl hydrolase, PslG_PA, from Pseudomonas aeruginosa was found to be able to inhibit biofilm formation by disintegrating exopolysaccharide in biofilms. Here, we investigate the potential spectrum of PslG homologous protein with anti-biofilm activity. One glycosyl hydrolase from Pseudomonas fluorescens, PslG_PF, exhibits anti-biofilm activities and the key catalytic residues of PslG_PF are conserved with those of PslG_PA. PslG_PF at concentrations as low as 50 nM efficiently inhibits the biofilm formation of P. aeruginosa and disassemble its preformed biofilm. Furthermore, PslG_PF exhibits anti-biofilm activity on a series of Pseudomonads, including P. fluorescens, Pseudomonas stutzeri and Pseudomonas syringae pv. phaseolicola. PslG_PF stays active under various temperatures. Our findings suggest that P. fluorescens glycosyl hydrolase PslG_PF has potential to be a broad spectrum inhibitor on biofilm formation of a wide range of Pseudomonads.