Assembly of a Biosynthetic Pathway for Production of Short-chain Alkane in Escherichia coli

Abstract

Development of biofuels from renewable resources is important to replacelimited fossil fuels. Here Escherichia Coli was metabolically engineeredto produce short-chain alkanes, free fatty acids, fatty esters and fatty alcoholsthrough the fatty acyl (acyl carrier protein (ACP)) to fatty acid to fattyacyl-CoA pathway. The fadE gene was deleted to block β-oxidation pathwayand prevent the degradation of fatty acyl-CoAs generated in vivo. Toincrease the conversion of short-chain fatty acids to SCAs, the activity of3-oxoacyl-ACP synthase (FabH) was enhanced by deleting the fadR geneand preventing upregulation of the fabA and fabB genes. A modifiedthioesterase was used to convert short-chain fatty acyl-ACPs to FFAs, whichwere then converted to SCAs. The final engineered strain produced up to580.8 mg l−1 of SCAs consisting of nonane, dodecane, tridecane, 2-methyldodecaneand tetradecane with small amounts of other hydrocarbons.Furthermore, this platform strain could produce short-chain FFAs andshort-chain fatty esters.(This work was supported by the Advanced BiomassResearch and Development Center of Korea (NRF-2010-0029799) throughthe Global Frontier Research Program of the Ministry of Science, ICT andFuture Planning (MSIP) through the National Research Foundation (NRF).Development of systems metabolic engineering platform technologies forbiorefineries funded by theMinistry of Education, Science and Technology)