New Pathways Developed to Higher Alcohols as Biofuels

The Science

Although much attention is currently focused on ethanol as a biofuel, other alcohols could be even more valuable, with energy densities closer to that of conventional gasoline (thus providing gas mileage comparable to that of gasoline), and less hygroscopic properties (which would simplify their distribution, for example in pipelines). The difficulty in implementing the use of higher alcohols is that no economical biosynthetic route has been developed to produce them in the large quantities needed (with the possible exception of 1-butanol). Now a research group at the UCLA-DOE Institute for Genomics and Proteomics has shown that straight-chain (such as 1-butanol) and branched-chain alcohols containing four and five carbons atoms can be produced using a common microbe, E. coli, by engineering the needed metabolic pathways to the desired products into the microbe. Their key breakthrough exploited redirection of existing highly efficient amino acid biosynthetic pathways in E. coli to the formation of the desired alcohols. Because of the universal presence of these amino acid pathways in all species, the strategy can be implemented in many different organisms, enabling the use of a large variety of raw materials, from cellulose to carbon dioxide.

Principal Investigator

James C. Liao
University of California–Los Angeles

BER Program Manager

Amy Swain

U.S. Department of Energy, Biological and Environmental Research (SC-33)
Biological Systems Science Division
[email protected]


The research was supported by the Genomics:GTL program in the Office of Biological & Environmental Research and appears in the January 3, 2008, issue of Nature.


Atsumi, S., T. Hanai, and J. C. Liao. 2008. “Non-Fermentative Pathways for Synthesis of Branched-Chain Higher Alcohols as Biofuels,” Nature 451, 86–9. DOI:10.1038/nature06450.