Establishment of a Platform Strain for Production of Short-Chain Fatty Acids and Alkane through Metabolic Engineering

Development of biofuels from renewable resources is important to replace limited fossil fuels. Here Escherichia Coli was metabolically engineered to produce short-chain alkanes, free fatty acids, fatty esters and fatty alcohols through the fatty acyl (acyl carrier protein (ACP)) to fatty acid to fatty acyl-CoA pathway. The fadE gene was deleted to block β-oxidation pathway and prevent the degradation of fatty acyl-CoAs generated in vivo. To increase the conversion of short-chain fatty acids to SCAs, the activity of 3-oxoacyl-ACP synthase (FabH) was enhanced by deleting the fadR gene and preventing upregulation of the fabA and fabB genes. A modified thioesterase was used to convert short-chain fatty acyl-ACPs to FFAs, which were then converted to SCAs. The final engineered strain produced up to 580.8 mg l⁻¹ of SCAs consisting of nonane, dodecane, tridecane, 2-methyl-dodecane and tetradecane with small amounts of other hydrocarbons. Furthermore, this platform strain could produce short-chain FFAs and short-chain fatty esters. (This work was supported by the Advanced Biomass Research and Development Center of Korea (NRF-2010-0029799) through the Global Frontier Research Program of the Ministry of Science, ICT and Future Planning (MSIP) through the National Research Foundation (NRF). And this work was supported by the Technology Development Program to Solve Climate Changes on Systems Metabolic Engineering for Biorefineries from the Ministry of Science, ICT and Future Planning (MSIP) through the National Research Foundation (NRF) of Korea (NRF-2012M1A2A2026556 and NRF-2012M1A2A2026557))