EFFECTS OF PENTACHLOROPHENOL UPON THE EXPRESSION OF OUTER-MEMBRANE PROTEINS, AND ROLE OF EXOPOLYSACCHARIDE AND LIPOPOLYSACCHARIDE IN THE TOLERANCE OF PSEUDOMONAS-FLUORESCENS TO THIS COMPOUND

The role of exopolysaccharide (EPS), lipopolysaccharide (LPS) and oute r membrane proteins (OMPs) in the tolerance of Pseudomonas fluorescens to pentachlorophenol (PCP) was investigated. Two strains of FI fluore scens were cultivated in R2A broth supplemented with 5.0 mmol l(-1) so dium salicylate or 2.75 mmol l(-1) EDTA, and the tolerance to PCP in t he presence of these compounds was determined. In addition, the expres sion of OMPs was also studied by using electrophoresis in polyacrylami de-SDS-urea gels. Sodium salicylate inhibited the biofilm formation of both strains. Neither sodium salicylate nor EDTA modified the levels of tolerance to PCP, indicating that such tolerance was not related to structures such as EPS or LPS. Three OMPs (46.9 to 88.1 kD) modified their expression levels in the presence of PCP. The results suggest th at the observed tolerance to PCP in the strains might be associated wi th OMP expression.