U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights

Higher Yields of Advanced Biofuels from Genetically Engineered Yeast
Published: July 27, 2013
Posted: February 07, 2014

The development of renewable substitutes for fuels and chemicals supplied by petroleum is an important aspect of achieving energy security. Currently, the United States annually produces more than 10 billion gallons of the biofuel ethanol from microbial fermentation of corn sugars using yeast. As this industry has matured, it has become clear that ethanol is not an ideal gasoline replacement due to its low-energy density, handling challenges, and limited compatibility with the current transportation fleet. Focus therefore has shifted to the production of advanced biofuels, designed to be “drop-in” fuels, having the same properties as gasoline, diesel, or jet fuel. Researchers at the Joint BioEnergy Institute (JBEI) recently achieved the highest ever reported yields of drop-in fuel precursors in yeast. Diesel fuels are composed mainly of long-chain hydrocarbon esters, similar to the fatty acids produced by yeast and other microorganisms for construction of their cell membranes. Overproduction of fatty acids in yeast is no easy task as elaborate regulatory and feedback systems exist to prevent excessive accumulation of these building blocks. To overcome this hurdle, the JBEI researchers replaced the highly-regulated native promoters for fatty acid production machinery with new high-intensity promoters. These promoters are effectively always “on,” directing the cell to make more fatty acid assembly machinery. The researchers also engineered cellular machinery to reroute fatty acids from cell membrane manufacture to free fatty acids that can be transformed through industrial processes to drop-in biofuels. These engineering changes led to an over 500-fold increase in production of free fatty acids when compared to the native strain. Strains also were engineered to produce drop-in biofuels directly, rerouting fatty acids into fatty alcohols and fatty acid ethyl esters that can be used in diesel engines. With these increased yields of fatty alcohols and fatty acid ethyl esters, this work represents a major advance toward production of next generation drop-in biofuels.

Reference: Runguphan, W., and J. D. Keasling. 2013. “Metabolic Engineering of Sacchromyces cerevisiae for Production of Fatty Acid-Derived Biofuels and Chemicals,” Metabolic Engineering 21, 103 €"13. (Reference link)

Contact: Kent Peters, SC-23.2, (301) 903-5549
Topic Areas:

  • Research Area: Microbes and Communities
  • Research Area: Sustainable Biofuels and Bioproducts
  • Research Area: DOE Bioenergy Research Centers (BRC)
  • Research Area: Biosystems Design

Division: SC-23.2 Biological Systems Science Division, BER


BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

May 10, 2019
Quantifying Decision Uncertainty in Water Management via a Coupled Agent-Based Model
Considering risk perception can improve the representation of human decision-making processes in age [more...]

May 09, 2019
Projecting Global Urban Area Growth Through 2100 Based on Historical Time Series Data and Future Scenarios
Study provides country-specific urban area growth models and the first dataset on country-level urba [more...]

May 05, 2019
Calibrating Building Energy Demand Models to Refine Long-Term Energy Planning
A new, flexible calibration approach improved model accuracy in capturing year-to-year changes in bu [more...]

May 03, 2019
Calibration and Uncertainty Analysis of Demeter for Better Downscaling of Global Land Use and Land Cover Projections
Researchers improved the Demeter model’s performance by calibrating key parameters and establi [more...]

Apr 22, 2019
Representation of U.S. Warm Temperature Extremes in Global Climate Model Ensembles
Representation of warm temperature events varies considerably among global climate models, which has [more...]

List all highlights (possible long download time)