The use of picolinyl esters for the characterization of microbial lipids: application to the unsaturated and cyclopropane fatty acids of campylobacter species

Picolinyl esters have been recently introduced for the mass spectrometric structure determination of unsaturated and cyclopropane fatty acids. We have used these derivatives to characterize the unsaturated and cyclopropane acids of Campylobacter species. The principle unsaturated acids were shown to be 11‐octadecenoic acid, with smaller amounts of 9‐hexadecenoic acid, 9‐octadecenoic acid and 9, 11‐octadecadienoic acid. The only cyclopropane acid present was cis 11, 12‐methylene octadecanoic acid. There was no interspecific variation in the position of unsatu‐ration or methylene bridges, even in the recently discovered gastric Campylobacter like organisms (GCLO) or the urease positive thermophilic Campylobacters (UPTC), the fatty acid profiles of which were consistent with their inclusion in the genus Campylobacter.