Fermentative production of short-chain fatty acids in Escherichia coli

• DOI: 10.1099/mic.0.078329-0
• Publication Date: 2014-04-11T04:27:19Z
• Authors: Alexandra R. Volker; David S. Gogerty; Christian Barthol...; Tracie Hennen-Bie...; Huilin Zhu; Thomas A. Bobik
• Keywords: Thioesterase; Thiolase; Metabolic Engineering; Product inhibition; Coenzyme A; Short-chain fatty acid; Ethyl hexanoate

Escherichia coli was engineered for the production of even- and odd-chain fatty acids (FAs) by fermentation. Co-production thiolase, hydroxybutyryl-CoA dehydrogenase, crotonase trans -enoyl-CoA reductase from a synthetic operon allowed butyrate, hexanoate octanoate. Elimination native fermentation pathways genetic deletion (Δ ldhA , Δ adhE ackA pta frdC ) helped eliminate undesired by-products increase product yields. Initial butyrate rates were high (0.7 g l −1 h but quickly levelled off further study suggested this due to toxicity and/or acidification growth medium. Results also showed that endogenous thioesterases significantly influenced formation. In particular, yciA thioesterase gene substantially increased while decreasing butyrate. E. co-produce enzymes even-chain FA (described above) together with coenzyme B 12 -dependent pathway propionyl-CoA, which FAs (pentanoate heptanoate). The used here has potential allow single substrate (glucose) in more energy-efficient manner than prior methods.