title: Microbial production of 1-octanol: A naturally excreted biofuel with diesel-like properties.
abstract: The development of sustainable, bio-based technologies to convert solar energy and carbon dioxide into fuels is a grand challenge. A core part of this challenge is to produce a fuel that is compatible with the existing transportation infrastructure. This task is further compounded by the commercial desire to separate the fuel from the biotechnological host. Based on its fuel characteristics, 1-octanol was identified as an attractive metabolic target with diesel-like properties. We therefore engineered a synthetic pathway specifically for the biosynthesis of 1-octanol inEscherichia coliBL21(DE3) by over-expression of three enzymes (thioesterase, carboxylic acid reductase and aldehyde reductase) and one maturation factor (phosphopantetheinyl transferase). Induction of this pathway in a shake flask resulted in 4.4 mg 1-octanol L-1h-1which exceeded the productivity of previously engineered strains. Furthermore, the majority (73%) of the fatty alcohol was localised within the media without the addition of detergent or solvent overlay. The deletion ofacrAreduced the production and excretion of 1-octanol by 3-fold relative to the wild-type, suggesting that the AcrAB-TolC complex may be responsible for the majority of product efflux. This study presents 1-octanol as a potential fuel target that can be synthesised and naturally accumulated within the media using engineered microbes.
authors.affiliation: Department of Biochemistry, University of Turku, Tykistökatu 6B 4krs, 20520 Turku, Finland; Department of Biochemical Engineering, University College London, Torrington Place, London WC1E 7JE, UK.
authors.forename: M Kalim
authors.initials: MK
authors.lastname: Akhtar
authors.affiliation: Department of Biochemistry, University of Turku, Tykistökatu 6B 4krs, 20520 Turku, Finland.
authors.forename: Hariharan
authors.initials: H
authors.lastname: Dandapani
authors.affiliation: Department of Biochemistry, University of Turku, Tykistökatu 6B 4krs, 20520 Turku, Finland.
authors.forename: Kati
authors.initials: K
authors.lastname: Thiel
authors.affiliation: Department of Biochemistry, University of Turku, Tykistökatu 6B 4krs, 20520 Turku, Finland; Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, London SW7 2AZ, UK.
authors.forename: Patrik R
authors.initials: PR
authors.lastname: Jones
keywords: 1-Octanol; Biofuel; Diesel; Excretion; Fatty alcohol