title: Global metabolic rewiring for improved CO2fixation and chemical production in cyanobacteria.
abstract: Cyanobacteria have attracted much attention as hosts to recycle CO2into valuable chemicals. Although cyanobacteria have been engineered to produce various compounds, production efficiencies are too low for commercialization. Here we engineer the carbon metabolism of Synechococcus elongatus PCC 7942 to improve glucose utilization, enhance CO2fixation and increase chemical production. We introduce modifications in glycolytic pathways and the Calvin Benson cycle to increase carbon flux and redirect it towards carbon fixation. The engineered strain efficiently uses both CO2and glucose, and produces 12.6 g l-1of 2,3-butanediol with a rate of 1.1 g l-1d-1under continuous light conditions. Removal of native regulation enables carbon fixation and 2,3-butanediol production in the absence of light. This represents a significant step towards industrial viability and an excellent example of carbon metabolism plasticity.
authors.affiliation: Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, USA.|Asahi Kasei Corporation, 2767-11 Niihama, Shionasu, Kojima, Kurashiki, Okayama 711-8510, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kanno
authors.affiliation: Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, USA.
authors.forename: Austin L
authors.initials: AL
authors.lastname: Carroll
authors.affiliation: Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, USA.
authors.forename: Shota
authors.identifier: 0000-0002-5782-4196
authors.initials: S
authors.lastname: Atsumi
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002072:Butylene Glycols / Q000378:metabolism*; D057486:Carbon Cycle; D002245:Carbon Dioxide / Q000378:metabolism*; D005285:Fermentation; D015964:Gene Expression Regulation, Bacterial; D005947:Glucose / Q000378:metabolism*; D006019:Glycolysis / Q000235:genetics; D060847:Metabolic Engineering / Q000379:methods; D010788:Photosynthesis; D046940:Synechococcus / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D002072:Butylene Glycols; D002245:Carbon Dioxide; C026978:2,3-butylene glycol; D005947:Glucose