Fatty Acid Ethyl Esters (FAEE) are one of the types of esters known as biodiesel. These esters are less commonly produced industrially than FAME because methanol is cheaper and more abundant than ethanol [1]. The most common method of FAEE production industrially is via the chemical pathway; the chemical catalysis is driven by alkali catalysts, however an acid catalyst may also be used. The biochemical pathways displayed are not to industrial scale. The lipase transesterification of triacylglycerols to FAEE occurs in Chromobacterium viscosum [2]. The second biochemical pathway was engineered into an Escherichia coli strain.   The essential enzyme in the pathway is wax ester synthase/acyl-coenzyme A: diacylglycerol acyltransferase from Acinetobacter baylyi strain ADP1. This enzyme is an unspecific acyltransferase, which can be used to synthesize long chain esters. Ethanol production in this recombinant E. coli is dramatically increased by coexpression of ethanol production genes from Zymomonas mobilis [3].

The following is a fatty acid ethyl ester (FAEE) pathway map. For the biological pathway, organisms which carry out the pathway are given above, but other organisms may also carry out this biochemistry. Follow the links for more information on compounds or reactions.

[1] Fukuda, H., Kondo, A., Noda, H., 2001, J. Biosci. Bioeng. 92, 405
[2] Shah, S., Sharma, S., Gupta, M.N., 2004, Energy Fuels 18, 154-159
[3] Kalscheuer, R., Stölting, T., Steinbüchel A., 2006, Microbiol 152, 2529-2536