Peculiarities of fatty acid composition of the genusCaulobacter

The fatty acid composition of 35 strains of stalked bacteria belonging to 17 of the hitherto described 19 species and 10 unidentified strains of the genusCaulobacter was studied. ll-Methyl-cis-octadec-11-enoic acid presumably synthesized fromcis-vaccenic acid was detected in all the strains in amounts of 0.4 – 34.7 % and was considered as a chemotaxonomic marker of the genus. During growth on a peptone-yeast medium, the caulobacters synthesized, along with the fatty acids which are typical of gram-negative bacteria, some normal and branched fatty acids with 15 and 17 carbon atoms (1–49 %). The synthesis of these acids was inhibited by glucose. The cell shape of stalked bacteria (fusiform, vibrioid or bacteroid) is not obviously associated with the contents of individual fatty acids.