title: Acetone production with metabolically engineered strains of Acetobacterium woodii.
abstract: Expected depletion of oil and fossil resources urges the development of new alternative routes for the production of bulk chemicals and fuels beyond petroleum resources. In this study, the clostridial acetone pathway was used for the formation of acetone in the acetogenic bacterium Acetobacterium woodii. The acetone production operon (APO) containing the genes thlA (encoding thiolase A), ctfA/ctfB (encoding CoA transferase), and adc (encoding acetoacetate decarboxylase) from Clostridium acetobutylicum were cloned under the control of the thlA promoter into four vectors having different replicons for Gram-positives (pIP404, pBP1, pCB102, and pCD6). Stable replication was observed for all constructs. A. woodii [pJIR_actthlA] achieved the maximal acetone concentration under autotrophic conditions (15.2±3.4mM). Promoter sequences of the genes ackA from A. woodii and pta-ack from C. ljungdahlii were determined by primer extension (PEX) and cloned upstream of the APO. The highest acetone production in recombinant A. woodii cells was achieved using the promoters PthlA and Ppta-ack. Batch fermentations using A. woodii [pMTL84151_actthlA] in a bioreactor revealed that acetate concentration had an effect on the acetone production, due to the high Km value of the CoA transferase. In order to establish consistent acetate concentration within the bioreactor and to increase biomass, a continuous fermentation process for A. woodii was developed. Thus, acetone productivity of the strain A. woodii [pMTL84151_actthlA] was increased from 1.2mgL(-1)h(-1) in bottle fermentation to 26.4mgL(-1)h(-1) in continuous gas fermentation.
authors.affiliation: Institut für Mikrobiologie und Biotechnologie, Universität Ulm, Albert-Einstein-Allee 11, D-89081 Ulm, Germany. Electronic address: Sabrina.Hoffmeister@uni-ulm.de.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Hoffmeister
authors.affiliation: Evonik Technology & Infrastructure GmbH, Process Technology & Engineering, Bioprocess Technology & Life Cycle Management, Paul-Baumann-Straße 1, D-45772 Marl, Germany.
authors.forename: Marzena
authors.initials: M
authors.lastname: Gerdom
authors.affiliation: Institut für Mikrobiologie und Biotechnologie, Universität Ulm, Albert-Einstein-Allee 11, D-89081 Ulm, Germany.
authors.forename: Frank R
authors.initials: FR
authors.lastname: Bengelsdorf
authors.affiliation: Institut für Mikrobiologie und Biotechnologie, Universität Ulm, Albert-Einstein-Allee 11, D-89081 Ulm, Germany.
authors.forename: Sonja
authors.initials: S
authors.lastname: Linder
authors.affiliation: Institut für Mikrobiologie und Biotechnologie, Universität Ulm, Albert-Einstein-Allee 11, D-89081 Ulm, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Flüchter
authors.affiliation: Institut für Mikrobiologie und Biotechnologie, Universität Ulm, Albert-Einstein-Allee 11, D-89081 Ulm, Germany.
authors.forename: Hatice
authors.initials: H
authors.lastname: Öztürk
authors.affiliation: Evonik Technology & Infrastructure GmbH, Process Technology & Engineering, Bioprocess Technology & Life Cycle Management, Paul-Baumann-Straße 1, D-45772 Marl, Germany.
authors.forename: Wilfried
authors.initials: W
authors.lastname: Blümke
authors.affiliation: Abteilung Mikrobiologie, Institut für Biowissenschaften, Universität Rostock, Albert-Einstein-Str. 3, D-18051 Rostock, Germany.
authors.forename: Antje
authors.initials: A
authors.lastname: May
authors.affiliation: Abteilung Mikrobiologie, Institut für Biowissenschaften, Universität Rostock, Albert-Einstein-Str. 3, D-18051 Rostock, Germany.
authors.forename: Ralf-Jörg
authors.initials: RJ
authors.lastname: Fischer
authors.affiliation: Abteilung Mikrobiologie, Institut für Biowissenschaften, Universität Rostock, Albert-Einstein-Str. 3, D-18051 Rostock, Germany.
authors.forename: Hubert
authors.initials: H
authors.lastname: Bahl
authors.affiliation: Institut für Mikrobiologie und Biotechnologie, Universität Ulm, Albert-Einstein-Allee 11, D-89081 Ulm, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Dürre
mesh_terms: D000085:Acetates / Q000378:metabolism*; D045855:Acetobacterium / Q000502:physiology*; D000096:Acetone / Q000302:isolation & purification / Q000378:metabolism*; D053898:Biosynthetic Pathways / Q000502:physiology*; D002245:Carbon Dioxide / Q000378:metabolism*; D024861:Genetic Enhancement / Q000379:methods; D060847:Metabolic Engineering / Q000379:methods*; D053858:Metabolic Networks and Pathways / Q000502:physiology*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D000085:Acetates; D011994:Recombinant Proteins; D000096:Acetone; D002245:Carbon Dioxide
keywords: Acetobacterium woodii; Acetone; Carbon dioxide; CoA transferase; Continuous gas fermentation; Replicon for Gram-positives; Syngas