Strains ofPseudomonas syringaepv. porri are characterized by a number of pathovar-specific phenotypic and genomic characters and constitute a highly homogeneous group. Using monoclonal antibodies, they all were classified in a novelP. syringaeserogroup O9. The O polysaccharides (OPS) isolated from the lipopolysaccharides (LPS) of P. syringaepv. porri NCPPB 3365 and NCPPB 3364 T possess multiple oligosaccharide O repeats, some of which are linear and composed ofL-rhamnose (L-Rha), whereas the major O repeats are branched with L-rhamnose in the main chain and GlcNAc in side chains (structures1and2). Both branched O repeats, which differ in the position of substitution of one of the Rha residues and in the site of attachment of GlcNAc, were found in the.
