title: Assessment of bacterial acyltransferases for an efficient lipid production in metabolically engineered strains of E. coli.
abstract: Microbially produced lipids like triacylglycerols or fatty acid ethyl esters are currently of great interest as fuel replacements or other industrially relevant compounds. They can even be produced by non-oleaginous microbes, like Escherichia coli, upon metabolic engineering. However, there is still much room for improvement regarding the yield for a competitive microbial production of lipids or biofuels. We genetically engineered E. coli by expressing fadD, fadR, pgpB, plsB and 'tesA in combination with atfA from Acinetobacter baylyi. A total fatty acid contents of up to 16% (w/w) was obtained on complex media, corresponding to approximately 9% (w/w) triacylglycerols and representing the highest titers of fatty acids and triacylglycerols obtained in E. coli under comparable cultivation conditions, so far. To evaluate further possibilities for an optimization of lipid production, ten promising bacterial wax ester synthase/acyl-Coenzyme A:diacylglycerol acyltransferases were tested and compared. While highest triacylglycerol storage was achieved with AtfA, the mutated variant AtfA-G355I turned out to be most suitable for fatty acid ethyl ester biosynthesis and enabled an accumulation of approx. 500 mg/L without external ethanol supplementation.
authors.affiliation: Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany.
authors.forename: Annika
authors.initials: A
authors.lastname: Röttig
authors.affiliation: Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany.
authors.forename: Paul Jannis
authors.initials: PJ
authors.lastname: Zurek
authors.affiliation: Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany; Faculty of Environmental Sciences, King Abdulaziz University, Jeddah, Saudi Arabia. Electronic address: steinbu@uni-muenster.de.
authors.forename: Alexander
authors.initials: A
authors.lastname: Steinbüchel
mesh_terms: D000150:Acinetobacter / Q000235:genetics / Q000378:metabolism; D000217:Acyltransferases / Q000235:genetics* / Q000378:metabolism*; D056804:Biofuels; D051048:Diacylglycerol O-Acyltransferase / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics*; D000431:Ethanol / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D008055:Lipids / Q000096:biosynthesis*; D060847:Metabolic Engineering / Q000379:methods*; D010957:Plasmids / Q000235:genetics; D014280:Triglycerides / Q000378:metabolism
chemical_list: D056804:Biofuels; D005227:Fatty Acids; D008055:Lipids; D014280:Triglycerides; D000431:Ethanol; D000217:Acyltransferases; D051048:Diacylglycerol O-Acyltransferase; C079165:long-chain-alcohol O-fatty-acyltransferase
keywords: Biofuel; Escherichia coli; Fatty acid ethyl ester; Triacylglycerol; WS/DGAT acyltransferase