Fatty Acid Methyl Ester Profiles of the Genus Agrobacterium.

Abstract

Profiles of the whole-cell fatty acid methyl esters (FAMEs) of 65 strains (including 16 overseas strains) of Agrobacterium were analyzed by gas-liquid chromatography. Principal component analysis, using 10 FAMEs out of the 12 detected, enabled us to separate the 65 strains into 3 distinct groups (Groups I, II and III). Biovars 1, 2 and 3 belonged to Groups I, II and III, respectively, indicating that each biovar is homogeneous and different from one another in terms of FAME profiles. Biovar 1 was separated from biovar 3 based on the quantitative differences in 16:1 and 18:1, and on the presence of 17:0 CYCLO. On the other hand, the quantitative difference in 19:0 CYCLO, the presence of 15:0 ISO 3OH and the absence of 18:1 3OH enabled separation of biovar 2 from biovars 1 and 3. The FAMEs of strain NCPPB 1650 and 2 strains of A. rubi (IFO 13261 and 13260) were similar to those of biovar 3, except that the latter lacked 17:0 CYCLO. The phenotypically unique 6 strains of A. tumefaciens isolated from kiwifruit (K-Ag-3, 4) and cherry (Ch-Ag-4, 5, 7 and 8) corresponded to biovar 2 in terms of FAME profiles. Thus, the use of FAME profiles was found to be a rapid and accurate method for the identification of the biovars.