Scientists from the Joint BioEnergy Institute have created a new type of renewable biofuel based on fragrant terpenes found in fir trees. The Joint BioEnergy Institute (JBEI) is a U.S. Department of Energy Research Center that aims to advance the development of the next generation of biofuels – liquid fuels derived from solar energy stored in plant biomass.
Terpenes are a diverse class of chemical compounds produced by a variety of plants. Terpenes are found in high concentrations in conifers and give these trees their distinctive odor.
Scientists from JBEI noticed that a terpene called bisabolane had a chemical structure similar to that of the hydrocarbons that make up diesel fuel. It also has chemical properties that are noncorrosive and would likely improve the performance of trucks operating in cold weather. They decided to investigate if they could produce enough bisabolane to make it a viable and greener alternative to diesel fuel.
To produce the new biofuel in large amounts, the scientists used genetic engineering to transfer the cellular machinery that produces bisabolane in fir trees into fast growing bacteria (Escherichia coli) and yeast (Saccharomyces cerevisiae). Taek Soon Lee, who led the team of researchers at JBEI, explained their experimental approach in a press release:
Although plants are the natural source of terpene compounds, engineered microbial platforms would be the most convenient and cost-effective approach for large-scale production of advanced biofuels.
The scientists were successful at coaxing the microorganisms into producing large quantities of the bisabolane precursor, bisabolene. Then, they simply added a chemical hydrogenation reaction into their production process to convert the biosynthetic bisabolene into bisabolane.
Approximately 22 billion gallons (83 billion liters) of diesel fuel were consumed by trucks in the United States during 2010. The development of a renewable source of diesel fuel would be a great gift that could help to improve the environment and national energy security.
The scientists still face the challenge of scaling up their new biofuel technology to a commercial level of production. They are planning on moving to this next phase of their research at the Lawrence Berkeley National Laboratory’s Advanced Biofuels Process Demonstration Unit, which is a 15,000 square foot facility available to U.S. Department of Energy-supported researchers, academic institutions, non-profit research organizations, and companies involved in biofuels R&D.
A paper [pdf] describing the microbial production of the terpene-based advanced biofuel was published previously on September 27, 2011 in the journal Nature Communications.
Deanna Conners is an Environmental Scientist who holds a Ph.D. in Toxicology and an M.S. in Environmental Studies. Her interest in toxicology stems from having grown up near the Love Canal Superfund Site in New York. Her current work is to provide high-quality scientific information to the public and decision-makers and to help build cross-disciplinary partnerships that help solve environmental problems. She writes about Earth science and nature conservation for EarthSky.