Characterization of Fatty Acid Methyl Ester Content ofClavibacter michiganensissubsp.michiganensis

(...) The presence of unsaturated branched-chain a15:1, anteisopentadecenoic acid, was highly specific for C.m. michiganensis. When the amount of a15:1 exceeded 2.56% of the total profile, the confidence level for identification was P = 0.10. Other qualitative and quantitative differences in FAMEs also were used to distinguish C.m. michiganensis from morphologically similar gram-positive bacteria that grew on semiselective media. When plotted three dimensionally, FAMEs defined a spatial relationship among strains of C.m. michiganensis. The technique was used as an accurate and rapid method for the characterization of bacteria recovered from irrigation ponds, seed, soil, transplants, and weeds