Microbial production of fatty-acid-derived fuels and chemicals from plant biomass

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Increasing energy costs and environmental concerns have emphasized the need to produce sustainable renewable fuels and chemicals1. Major efforts to this end are focused on the microbial production of high-energy fuels by cost-effective ‘consolidated bioprocesses’2. Fatty acids are composed of long alkyl chains and represent nature’s ‘petroleum’, being a primary metabolite used by cells for both chemical and energy storage functions. These energy-rich molecules are today isolated from plant and animal oils for a diverse set of products ranging from fuels to oleochemicals. A more scalable, controllable and economic route to this important class of chemicals would be through the microbial conversion of renewable feedstocks, such as biomass-derived carbohydrates. Here we demonstrate the engineering of Escherichia coli to produce structurally tailored fatty esters (biodiesel), fatty alcohols, and waxes directly from simple sugars. Furthermore, we show engineering of the biodiesel-producing cells to express hemicellulases, a step towards producing these compounds directly from hemicellulose, a major component of plant-derived biomass.

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E.J.S. was supported by the Tien Scholar Environmental Fellowship and the Synthetic Biology Engineering Research Center (SynBERC). Y.K. and G.B. were supported by a grant from LS9, Inc. (South San Francisco, California) through the University of California Discovery Grant program. This research was performed at the Joint BioEnergy Institute. We thank M. Rude with help on the manuscript and J. Cronan and the LS9 Scientific Advisory Board for technical insight and discussion.

Author Contributions E.J.S., Y.K., G.B., Z.H., A.S., A.M., S.B.d.C. and J.D.K. conceived of the experiments. E.J.S. and Y.K. constructed the strains and metabolic pathways for fatty-acid-derived products and performed the production experiments. LS9 engineered and evaluated FAEE and fatty alcohol producing strains for thioesterase evaluations. G.B. conceived, constructed and performed the xylan-metabolizing pathway growth experiments. E.J.S. and Y.K. constructed the xylan-metabolizing, fatty acid production strain and performed the production experiments. E.J.S., Y.K., A.S., S.B.d.C. and J.D.K. drafted the manuscript. All authors approved the final manuscript.

Author information

Author notes

    • Eric J. Steen
    •  & Yisheng Kang

    These authors contributed equally to this work.


  1. Joint BioEnergy Institute,

    • Eric J. Steen
    • , Yisheng Kang
    • , Gregory Bokinsky
    •  & Jay D. Keasling
  2. Synthetic Biology Engineering Research Center, 5885 Hollis Avenue, Emeryville, California 94608, USA

    • Eric J. Steen
    •  & Jay D. Keasling
  3. Departmient of Bioengineering,

    • Eric J. Steen
    •  & Jay D. Keasling
  4. QB3 Institute,

    • Yisheng Kang
    • , Gregory Bokinsky
    •  & Jay D. Keasling
  5. Department of Chemical Engineering, University of California, Berkeley, California 94720, USA

    • Jay D. Keasling
  6. LS9, Inc., 100 Kimball Way, South San Francisco, California 94080, USA

    • Zhihao Hu
    • , Andreas Schirmer
    • , Amy McClure
    •  & Stephen B. del Cardayre
  7. Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA

    • Jay D. Keasling


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Competing interests

J.D.K. has financial interests in Amyris and LS9, both of which are involved in producing advanced biofuels. Z.H., A.S., A.M. and S.B.d.C. have a financial interest in LS9.

Corresponding authors

Correspondence to Stephen B. del Cardayre or Jay D. Keasling.

Supplementary information

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  1. 1.

    Supplementary Information

    This file contains Supplementary Tables 1-2, Supplementary Figures 1-3 with Legends and Supplementary References.


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