title: Cell-free metabolic engineering: production of chemicals by minimized reaction cascades.
abstract: The limited supply of fossil resources demands the development of renewable alternatives to petroleum-based products. Here, biobased higher alcohols such as isobutanol are versatile platform molecules for the synthesis of chemical commodities and fuels. Currently, their fermentation-based production is limited by the low tolerance of microbial production systems to the end products and also by the low substrate flux into cell metabolism. We developed an innovative cell-free approach, utilizing an artificial minimized glycolytic reaction cascade that only requires one single coenzyme. Using this toolbox the cell-free production of ethanol and isobutanol from glucose was achieved. We also confirmed that these streamlined cascades functioned under conditions at which microbial production would have ceased. Our system can be extended to an array of industrially-relevant molecules. Application of solvent-tolerant biocatalysts potentially allows for high product yields, which significantly simplifies downstream product recovery.
authors.affiliation: Lehrstuhl für Chemie Biogener Rohstoffe, Technische Universität München, Schulgasse 16, 94315 Straubing, Germany.
authors.forename: Jan-Karl
authors.initials: JK
authors.lastname: Guterl
authors.forename: Daniel
authors.initials: D
authors.lastname: Garbe
authors.forename: Jörg
authors.initials: J
authors.lastname: Carsten
authors.forename: Fabian
authors.initials: F
authors.lastname: Steffler
authors.forename: Bettina
authors.initials: B
authors.lastname: Sommer
authors.forename: Steven
authors.initials: S
authors.lastname: Reiße
authors.forename: Anja
authors.initials: A
authors.lastname: Philipp
authors.forename: Martina
authors.initials: M
authors.lastname: Haack
authors.forename: Broder
authors.initials: B
authors.lastname: Rühmann
authors.forename: Andre
authors.initials: A
authors.lastname: Koltermann
authors.forename: Ulrich
authors.initials: U
authors.lastname: Kettling
authors.forename: Thomas
authors.initials: T
authors.lastname: Brück
authors.forename: Volker
authors.initials: V
authors.lastname: Sieber
mesh_terms: D001419:Bacteria / Q000201:enzymology; D055162:Biocatalysis; D032701:Biomimetics / Q000379:methods*; D000440:Butanols / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D006019:Glycolysis; D060847:Metabolic Engineering / Q000379:methods*; D019289:Pyruvic Acid / Q000378:metabolism; D012997:Solvents / Q000737:chemistry
chemical_list: D000440:Butanols; D012997:Solvents; D000431:Ethanol; C040507:isobutyl alcohol; D019289:Pyruvic Acid; D005947:Glucose