title: Efficient odd straight medium chain free fatty acid production by metabolically engineered Escherichia coli.
abstract: Free fatty acids (FFAs) can be used as precursors for the production of biofuels or chemicals. Different composition of FFAs will be useful for further modification of the biofuel/biochemical quality. Microbial biosynthesis of even chain FFAs can be achieved by introducing an acyl-acyl carrier protein thioesterase gene into E. coli. In this study, odd straight medium chain FFAs production was investigated by using metabolic engineered E. coli carrying acyl-ACP thioesterase (TE, Ricinus communis), propionyl-CoA synthase (Salmonella enterica), and β-ketoacyl-acyl carrier protein synthase III (four different sources) with supplement of extracellular propionate. By using these metabolically engineered E. coli, significant quantity of C13 and C15 odd straight-chain FFAs could be produced from glucose and propionate. The highest concentration of total odd straight chain FFAs attained was 1205 mg/L by the strain HWK201 (pXZ18, pBHE2), and 85% of the odd straight chain FFAs was C15. However, the highest percentage of odd straight chain FFAs was achieved by the strain HWK201 (pXZ18, pBHE3) of 83.2% at 48 h. This strategy was also applied successfully in strains carrying different TE, such as the medium length acyl-ACP thioesterase gene from Umbellularia californica. C11 and C13 became the major odd straight-chain FFAs.
authors.affiliation: Department of Bioengineering, Rice University, Houston, Texas.
authors.forename: Hui
authors.initials: H
authors.lastname: Wu
authors.forename: Ka-Yiu
authors.initials: KY
authors.lastname: San
mesh_terms: D015099:3-Oxoacyl-(Acyl-Carrier-Protein) Synthase / Q000235:genetics / Q000378:metabolism; D003066:Coenzyme A Ligases / Q000235:genetics / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D005230:Fatty Acids, Nonesterified / Q000378:metabolism*; D060847:Metabolic Engineering / Q000379:methods*; D053858:Metabolic Networks and Pathways; D011422:Propionates / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012278:Ricinus / Q000201:enzymology / Q000235:genetics; D019779:Salmonella enterica / Q000201:enzymology / Q000235:genetics; D013869:Thiolester Hydrolases / Q000235:genetics / Q000378:metabolism; D027422:Umbellularia / Q000201:enzymology / Q000235:genetics
chemical_list: D003470:Culture Media; D005230:Fatty Acids, Nonesterified; D011422:Propionates; D011994:Recombinant Proteins; C077402:3-ketoacyl-acyl carrier protein synthase III; D015099:3-Oxoacyl-(Acyl-Carrier-Protein) Synthase; D013869:Thiolester Hydrolases; C018748:oleoyl-(acyl-carrier-protein) hydrolase; D003066:Coenzyme A Ligases; C068072:propionate - CoA ligase
keywords: Escherichia coli; fatty acid production; odd straight medium chain; propionyl-CoA synthase; β-ketoacyl-acyl carrier protein synthase III