title: Engineering Escherichia coli for odd straight medium chain free fatty acid production.
abstract: Microbial biosynthesis of free fatty acids (FFAs) can be achieved by introducing an acyl-acyl carrier protein thioesterase gene into Escherichia coli. The engineered E. coli usually produced even chain FFAs. In this study, propionyl-CoA synthetase (prpE) from Salmonella enterica was overexpressed in two efficient even chain FFAs producers, ML103 (pXZM12) carrying the acyl-ACP thioesterase gene from Umbellularia californica and ML103 (pXZ18) carrying the acyl-ACP thioesterase gene from Ricinus communis combined with supplement of extracellular propionate. With these metabolically engineered E. coli, the odd straight chain FFAs, undecanoic acid (C11:0), tridecanoic acid (C13:0), and pentadecanoic acid (C15:0) were produced from glucose and propionate. The highest total odd straight chain FFAs produced by ML103 (pXZM12, pBAD-prpE) reached 276 mg/l with a ratio of 23.43 % of the total FFAs. In ML103 (pXZ18, pBAD-prpE), the highest total odd straight chain FFAs accumulated to 297 mg/l, and the ratio reached 17.68 % of the total FFAs. Due to the different substrate specificity of the acyl-ACP thioesterases, the major odd straight chain FFA components of ML103 (pXZM12, pBAD-prpE) were undecanoic acid and tridecanoic acid, while the ML103 (pXZ18, pBAD-prpE) preferred pentadecanoic acid.
authors.affiliation: Department of Bioengineering, Rice University, Houston, TX, 77005, USA.
authors.forename: Hui
authors.initials: H
authors.lastname: Wu
authors.forename: Ka-Yiu
authors.initials: KY
authors.lastname: San
mesh_terms: D053898:Biosynthetic Pathways; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D005227:Fatty Acids / Q000096:biosynthesis* / Q000737:chemistry; D060847:Metabolic Engineering; D015394:Molecular Structure
chemical_list: D005227:Fatty Acids