Branched and Cyclic Fatty Acids and Methyl Esters

In bacteria, the methyl branched-fatty acid¹ content and composition can often be used as a taxonomic marker because specific fatty acids not commonly found in other microorganisms are often found in bacteria.² Branched chain fatty acids are critical for the regulation of fluidity in membranes and in membrane transport for many types of bacteria due to their significantly lower transition temperature than straight chain fatty acids. Some bacteria handle stress (such as heat and toxicity) by changing the ratio of anteiso/iso-fatty acids in the cell membrane.

References:

1. T. Kaneda “Iso- and Anteiso-Fatty Acids in Bacteria: Biosynthesis, Function, and Taxonomic Significancet” American Society for Microbiology, Vol. 55(2) pp. 288-302, 1991
2. N. Jensen and M. Gross “Fast Atom Bombardment and Tandem Mass Spectrometry for Determining Iso- and Anteiso-Fatty Acids” Lipids, Vol. 21(5) pp. 362-365, 1986