Production of 2-methyl-1-butanol in engineered Escherichia coli

Appl Microbiol Biotechnol. 2008 Nov;81(1):89-98. doi: 10.1007/s00253-008-1631-y. Epub 2008 Aug 29.

Abstract

Recent progress has been made in the production of higher alcohols by harnessing the power of natural amino acid biosynthetic pathways. Here, we describe the first strain of Escherichia coli developed to produce the higher alcohol and potential new biofuel 2-methyl-1-butanol (2MB). To accomplish this, we explored the biodiversity of enzymes catalyzing key parts of the isoleucine biosynthetic pathway, finding that AHAS II (ilvGM) from Salmonella typhimurium and threonine deaminase (ilvA) from Corynebacterium glutamicum improve 2MB production the most. Overexpression of the native threonine biosynthetic operon (thrABC) on plasmid without the native transcription regulation also improved 2MB production in E. coli. Finally, we knocked out competing pathways upstream of threonine production (DeltametA, Deltatdh) to increase its availability for further improvement of 2MB production. This work led to a strain of E. coli that produces 1.25 g/L 2MB in 24 h, a total alcohol content of 3 g/L, and with yields of up to 0.17 g 2MB/g glucose.

MeSH terms

  • 1-Butanol / metabolism*
  • Acetolactate Synthase / genetics
  • Acetolactate Synthase / metabolism
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Biosynthetic Pathways
  • Corynebacterium glutamicum / enzymology
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism*
  • Gene Deletion
  • Genetic Engineering*
  • Operon
  • Salmonella typhimurium / enzymology
  • Threonine Dehydratase / genetics
  • Threonine Dehydratase / metabolism

Substances

  • Bacterial Proteins
  • 1-Butanol
  • Acetolactate Synthase
  • Threonine Dehydratase