title: Production of 2-methyl-1-butanol and 3-methyl-1-butanol in engineered Corynebacterium glutamicum.
abstract: The pentanol isomers 2-methyl-1-butanol and 3-methyl-1-butanol represent commercially interesting alcohols due to their potential application as biofuels. For a sustainable microbial production of these compounds, Corynebacterium glutamicum was engineered for producing 2-methyl-1-butanol and 3-methyl-1-butanol via the Ehrlich pathway from 2-keto-3-methylvalerate and 2-ketoisocaproate, respectively. In addition to an already available 2-ketoisocaproate producer, a 2-keto-3-methylvalerate accumulating C. glutamicum strain was also constructed. For this purpose, we reduced the activity of the branched-chain amino acid transaminase in an available C. glutamicuml-isoleucine producer (K2P55) via a start codon exchange in the ilvE gene enabling accumulation of up to 3.67g/l 2-keto-3-methylvalerate. Subsequently, nine strains expressing different gene combinations for three 2-keto acid decarboxylases and three alcohol dehydrogenases were constructed and characterized. The best strains accumulated 0.37g/l 2-methyl-1-butanol and 2.76g/l 3-methyl-1-butanol in defined medium within 48h under oxygen deprivation conditions, making these strains ideal candidates for additional strain and process optimization.
authors.affiliation: Institute of Bio, and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, D-52425 Jülich, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Vogt
authors.affiliation: Institute of Bio, and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, D-52425 Jülich, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Brüsseler
authors.affiliation: Institute of Bio, and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, D-52425 Jülich, Germany.
authors.forename: Jan van
authors.initials: JV
authors.lastname: Ooyen
authors.affiliation: Institute of Bio, and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, D-52425 Jülich, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Bott
authors.affiliation: Institute of Bio, and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, D-52425 Jülich, Germany. Electronic address: j.marienhagen@fz-juelich.de.
authors.forename: Jan
authors.initials: J
authors.lastname: Marienhagen
mesh_terms: D053898:Biosynthetic Pathways / Q000235:genetics*; D000440:Butanols / Q000302:isolation & purification / Q000378:metabolism*; D048230:Corynebacterium glutamicum / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D024861:Genetic Enhancement / Q000379:methods*; D060847:Metabolic Engineering / Q000379:methods*; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D000637:Transaminases / Q000235:genetics*
chemical_list: D000440:Butanols; D000637:Transaminases
keywords: 2-keto acids; 2-methyl-1-butanol; 3-methyl-1-butanol; Biofuels; Corynebacterium glutamicum; Ehrlich pathway