title: Metabolic engineering of Cupriavidus necator for heterotrophic and autotrophic alka(e)ne production.
abstract: Alkanes of defined carbon chain lengths can serve as alternatives to petroleum-based fuels. Recently, microbial pathways of alkane biosynthesis have been identified and enabled the production of alkanes in non-native producing microorganisms using metabolic engineering strategies. The chemoautotrophic bacterium Cupriavidus necator has great potential for producing chemicals from CO2: it is known to have one of the highest growth rate among natural autotrophic bacteria and under nutrient imbalance it directs most of its carbon flux to the synthesis of the acetyl-CoA derived polymer, polyhydroxybutyrate (PHB), (up to 80% of intracellular content). Alkane synthesis pathway from Synechococcus elongatus (2 genes coding an acyl-ACP reductase and an aldehyde deformylating oxygenase) was heterologously expressed in a C. necator mutant strain deficient in the PHB synthesis pathway. Under heterotrophic condition on fructose we showed that under nitrogen limitation, in presence of an organic phase (decane), the strain produced up to 670mg/L total hydrocarbons containing 435mg/l of alkanes consisting of 286mg/l of pentadecane, 131mg/l of heptadecene, 18mg/l of heptadecane, and 236mg/l of hexadecanal. We report here the highest level of alka(e)nes production by an engineered C. necator to date. We also demonstrated the first reported alka(e)nes production by a non-native alkane producer from CO2 as the sole carbon source.
authors.affiliation: LISBP, Université de Toulouse, CNRS, INRA, INSA, 135 Avenue de Rangueil, 31077 Toulouse CEDEX 04, France. Electronic address: crepin@insa-toulouse.fr.
authors.forename: Lucie
authors.initials: L
authors.lastname: Crépin
authors.affiliation: LISBP, Université de Toulouse, CNRS, INRA, INSA, 135 Avenue de Rangueil, 31077 Toulouse CEDEX 04, France. Electronic address: elombard@insa-toulouse.fr.
authors.forename: Eric
authors.initials: E
authors.lastname: Lombard
authors.affiliation: LISBP, Université de Toulouse, CNRS, INRA, INSA, 135 Avenue de Rangueil, 31077 Toulouse CEDEX 04, France. Electronic address: stephane.guillouet@insa-toulouse.fr.
authors.forename: Stéphane E
authors.initials: SE
authors.lastname: Guillouet
mesh_terms: D000473:Alkanes / Q000302:isolation & purification / Q000378:metabolism*; D000475:Alkenes / Q000302:isolation & purification / Q000378:metabolism*; D052818:Autotrophic Processes / Q000502:physiology; D053898:Biosynthetic Pathways / Q000502:physiology; D002245:Carbon Dioxide / Q000378:metabolism*; D020118:Cupriavidus necator / Q000502:physiology*; D024861:Genetic Enhancement / Q000379:methods; D052836:Heterotrophic Processes / Q000502:physiology; D060847:Metabolic Engineering / Q000379:methods*; D053858:Metabolic Networks and Pathways / Q000502:physiology
chemical_list: D000473:Alkanes; D000475:Alkenes; D002245:Carbon Dioxide
keywords: Alkane; Alkene; Biofuels; Cupriavidus necator; Fermentation; Hydrocarbon; Metabolic engineering