COMPARATIVE ESTERASE ELECTROPHORETIC POLYMORPHISM AND PHENOTYPIC ANALYSIS OF XANTHOMONAS-MALTOPHILIA AND RELATED STRAINS

Membrane bound non-specific esterases of 52 Xanthomonas maltophilia an d related strains such as Pseudomonas betle, P. boreopolis, P. hibisci cola, P. pictorum and four Alcaligenes sp., are analysed by polyacryla mide gel electrophoresis and isoelectric focusing. A two dimensional e lectrophoretic profile relating for each electrophoretic variant the r elative mobility to the isoelectric point defines the degree of estera se polymorphism. The results of this analysis are compared to a numeri cal analysis of 29 discriminative phenotypic features examined in all the strains. The two taxonomic approaches are complementary and demons trate the existence of a core of X. maltophilia strains. They confirm that both P. betle and P. hibiscicola are synonyms of X. maltophilia. P. boreopolis, P. pictorum and five strains belonging to the X. maltop hilia biovar II as defined by Ikemoto et al. (1980) are clearly less r elated to the X. maltophilia core.