Protein and enzymatic criteria for the characterization of phytopathogenic Pseudomonas fluorescens

: Polyacrylamide gel electrophoresis of proteins was carried out to characterize eight bacterial strains belonging to the genus Pseudomonas. The sampling included three species (P. cichorii, P. viridiflava and P. syringae), with three pathovars for this last species (pv. pisi, pv. syringae, pv. tomato). Several molecular markers were evaluated: native proteins, denatured proteins, esterases, superoxide dismutases (SOD) and polyphenoloxidases (PPO). Each species or pathovar of Pseudomonas was clearly differentiated by esterase patterns. SOD, PPO and native protein patterns allowed strains of P. cichorii, P. viridiflava and P.s. pv. tomato also to be distinguished. Strains of P.s. pv. pisi and P.s. pv. syringae were identical for these criteria. Denatured protein patterns of these two pathovars and P. viridiflava were similar.