Metabolic engineering of Escherichia coli for 1-butanol and 1-propanol production via the keto-acid pathways

Metab Eng. 2008 Nov;10(6):312-20. doi: 10.1016/j.ymben.2008.08.001. Epub 2008 Aug 17.

Abstract

Production of higher alcohols via the keto-acid intermediates found in microorganism's native amino-acid pathways has recently shown promising results. In this work, an Escherichia coli strain that produces 1-butanol and 1-propanol from glucose was constructed. The strain first converts glucose to 2-ketobutyrate, a common keto-acid intermediate for isoleucine biosynthesis. Then, 2-ketobutyrate is converted to 1-propanol through reactions catalyzed by the heterologous decarboxylase and dehydrogenase, or to 1-butanol via the chemistry involved in the synthesis of the unnatural amino acid norvaline. We systematically improved the synthesis of 1-propanol and 1-butanol through deregulation of amino-acid biosynthesis and elimination of competing pathways. The final strain demonstrated a production titer of 2 g/L with nearly 1:1 ratio of butanol and propanol.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • 1-Butanol / metabolism*
  • 1-Propanol / metabolism*
  • Bioelectric Energy Sources*
  • Escherichia coli / physiology*
  • Escherichia coli Proteins / physiology*
  • Genetic Enhancement / methods*
  • Glucose / metabolism*
  • Keto Acids / metabolism*
  • Protein Engineering / methods
  • Recombinant Proteins / metabolism
  • Signal Transduction / physiology

Substances

  • Escherichia coli Proteins
  • Keto Acids
  • Recombinant Proteins
  • 1-Butanol
  • 1-Propanol
  • Glucose