Letter | Published:

Non-fermentative pathways for synthesis of branched-chain higher alcohols as biofuels

Nature volume 451, pages 8689 (03 January 2008) | Download Citation

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Abstract

Global energy and environmental problems have stimulated increased efforts towards synthesizing biofuels from renewable resources1,2,3. Compared to the traditional biofuel, ethanol, higher alcohols offer advantages as gasoline substitutes because of their higher energy density and lower hygroscopicity. In addition, branched-chain alcohols have higher octane numbers compared with their straight-chain counterparts. However, these alcohols cannot be synthesized economically using native organisms. Here we present a metabolic engineering approach using Escherichia coli to produce higher alcohols including isobutanol, 1-butanol, 2-methyl-1-butanol, 3-methyl-1-butanol and 2-phenylethanol from glucose, a renewable carbon source. This strategy uses the host’s highly active amino acid biosynthetic pathway and diverts its 2-keto acid intermediates for alcohol synthesis. In particular, we have achieved high-yield, high-specificity production of isobutanol from glucose. The strategy enables the exploration of biofuels beyond those naturally accumulated to high quantities in microbial fermentation.

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Acknowledgements

This work was partially supported by UCLA-DOE Institute for Genomics and Proteomics. We are grateful to H. Bujard for plasmids, and members of the Liao laboratory for discussion and comments on the manuscript.

Author Contributions S.A. and J.C.L. designed experiments; S.A. and T.H. performed the experiments; S.A. and J.C.L. analysed the data; and S.A. and J.C.L. wrote the paper.

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Affiliations

  1. Department of Chemical and Biomolecular Engineering,

    • Shota Atsumi
    • , Taizo Hanai
    •  & James C. Liao
  2. UCLA-DOE Insitute for Genomics and Proteomics, University of California, Los Angeles, 5531 Boelter Hall, 420 Westwood Plaza, Los Angeles, California 90095, USA

    • James C. Liao

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Competing interests

The University of California has filed a provisional patent application based on this work, and has licensed the technology to Gevo, a biofuel company. J.C.L. serves on the Scientific Advisory Board of Gevo. No financial support was received from Gevo to support this work.

Corresponding author

Correspondence to James C. Liao.

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https://doi.org/10.1038/nature06450

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