Engineering Production of Biofuels From Proteins

The Science

Biofuels currently are produced either from carbohydrates (e.g., ethanol from starch or sugar) or lipids (e.g., biodiesel from oils or fats). Both have serious shortcomings, requiring processes that have limited net energy efficiency and yielding byproducts such as nitrous oxide, a potent greenhouse gas. Research has now shown that the third major component of living organisms, proteins, could provide a large-scale source of biofuels without these limitations. Scientists at the UCLA-DOE Institute for Genomics and Proteomics have demonstrated that proteins produced in yeasts, bacteria, and algae can be converted efficiently into long-chain alcohols that are readily used in liquid fuels. The critical step in this research was to engineer metabolic processes into cells that convert the amino acids making up proteins into fuel molecules. These processes enable efficient deamination, or removal of the nitrogen-containing group from the amino acids and conversion of the resulting molecules into fuel alcohols. The nitrogen-containing byproducts are readily captured and recycled to fertilize growth of more of the photosynthetic cells, such as algae. The process can make effective use of sunlight as an energy source and CO2 as a carbon source, as proteins are the principal product of rapid growth in photosynthetic microorganisms.

Principal Investigator

James C. Liao

BER Program Manager

Amy Swain

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


Huo, Y.-X., K. M. Cho, J. G. Lafontaine Rivera, E. Monte, C. R. Shen, Y. Yan, and J. C. Liao. 2011. “Conversion of Proteins into Biofuels by Engineering Nitrogen Flux,” Nature Biotechnology. DOI:10.1038/nbt.1789.