IDENTIFICATION OF NONPATHOGENIC XANTHOMONAS STRAINS ASSOCIATED WITH PLANTS

A total of 70 presumptive non-pathogenic yellow-pigmented strains from different origins were identified to the genus Xanthomonas with the g enus-specific monoclonal antibodies (XI and XII), and fatty acid methy l ester (FAME) and sodium dodecyl sulfate-polyacrylamide gel electroph oresis (SDS-PAGE) protein databases. On the basis of FAME profiles and SDS-PAGE protein patterns, these non-pathogenic xanthomonads formed a heterogeneous population. Fourty-two strains were identified as the s ame species by both methods, whereas five strains were identified as d ifferent species. Only eight strains remained unidentified by both met hods, whereas in 15 cases the identification was ambiguous. The identi fication at pathovar level was usually ambiguous and nor concordant, w hich indicated that the non-pathogenic xanthomonads cannot be classifi ed in the described pathovars. None of the non-pathogenic xanthomonads was identified as belonging to the pathovars of the plant from which they were isolated.