Determination of monounsaturated double-bond position and geometry in the cellular fatty acids of the pathogenic bacterium Francisella tularensis.

The nonhydroxy fatty acid composition of Francisella tularensis is reported in detail. The double-bond configuration of the monounsaturated acids has been determined by capillary gas chromatography-mass spectrometry of the derivatized fatty acids. The monounsaturated fatty acids detected, in decreasing order of abundance, were 24:1 omega 15c, 18:1 omega 9c, 22:1 omega 13c, 20:1 omega 11c, 16:1 omega 7c, 26:1 omega 17c, and 14:1 omega 7c. The fatty acid profile found in F. tularensis, in particular the double-bond positions, represents a valuable taxonomic characteristic of this pathogenic bacterium.