title: Butyrate production under aerobic growth conditions by engineered Escherichia coli.
abstract: Butyrate is an important industrial platform chemical. Although several groups have reported butyrate production under oxygen-limited conditions by a native producer, Clostridium tyrobutylicum, and by a metabolically engineered Escherichia coli, efforts to produce butyrate under aerobic growth conditions have met limited success. Here, we constructed a novel butyrate synthetic pathway that functions under aerobic growth conditions in E. coli, by modifying the 1-butanol synthetic pathway reported previously. The pathway consists of phaA (acetyltransferase) and phaB (NADPH-dependent acetoacetyl-CoA reductase) from Ralstonia eutropha, phaJ ((R)-specific enoyl-CoA hydratase) from Aeromonas caviae, ter (trans-enoyl-CoA reductase) from Treponema denticola, and endogenous thioesterase(s) of E. coli. To evaluate the potential of this pathway for butyrate production, culture conditions, including pH, oxygen supply, and concentration of inorganic nitrogen sources, were optimized in a mini-jar fermentor. Under the optimal conditions, butyrate was produced at a concentration of up to 140 mM (12.3 g/L in terms of butyric acid) after 54 h of fed-batch culture.
authors.affiliation: Division of Agricultural Sciences, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi 753-8515, Japan; Research Center for Thermotolerant Microbial Resources, Yamaguchi University, Yamaguchi 753-8515, Japan. Electronic address: nkataoka@yamaguchi-u.ac.jp.
authors.forename: Naoya
authors.initials: N
authors.lastname: Kataoka
authors.affiliation: Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand; Center of Excellence in Hazardous Substance Management (HSM), Chulalongkorn University, Bangkok 10330, Thailand.
authors.forename: Alisa S
authors.initials: AS
authors.lastname: Vangnai
authors.affiliation: Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
authors.forename: Thunyarat
authors.initials: T
authors.lastname: Pongtharangkul
authors.affiliation: Division of Agricultural Sciences, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi 753-8515, Japan; Research Center for Thermotolerant Microbial Resources, Yamaguchi University, Yamaguchi 753-8515, Japan.
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Yakushi
authors.affiliation: Division of Agricultural Sciences, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi 753-8515, Japan; Research Center for Thermotolerant Microbial Resources, Yamaguchi University, Yamaguchi 753-8515, Japan.
authors.forename: Kazunobu
authors.initials: K
authors.lastname: Matsushita
mesh_terms: D020001:1-Butanol / Q000378:metabolism; D000123:Acetyltransferases / Q000235:genetics / Q000378:metabolism; D000332:Aerobiosis; D057585:Aeromonas caviae / Q000201:enzymology / Q000235:genetics; D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000378:metabolism; D061249:Batch Cell Culture Techniques; D019149:Bioreactors; D053898:Biosynthetic Pathways / Q000235:genetics*; D020148:Butyric Acid / Q000378:metabolism*; D003013:Clostridium / Q000378:metabolism; D020118:Cupriavidus necator / Q000201:enzymology / Q000235:genetics; D004746:Enoyl-CoA Hydratase / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D060847:Metabolic Engineering; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000235:genetics / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism / Q000494:pharmacology; D013869:Thiolester Hydrolases / Q000235:genetics / Q000378:metabolism; D048373:Treponema denticola / Q000201:enzymology / Q000235:genetics
chemical_list: D020148:Butyric Acid; D020001:1-Butanol; D000429:Alcohol Oxidoreductases; C023744:acetoacetyl-CoA reductase; D044925:Oxidoreductases Acting on CH-CH Group Donors; C434934:trans-2-enoyl-CoA reductase (NADPH); D000123:Acetyltransferases; D013869:Thiolester Hydrolases; C406162:R-specific trans-2,3-enoylacyl-CoA hydratase; D004746:Enoyl-CoA Hydratase; D010100:Oxygen
keywords: Aerobic synthesis; Butyrate; Escherichia coli; Fermentation; Synthetic pathway