WALNUT CREEK, Calif.The nation's Renewable Fuels Standard calls for annual production of 36 billion gallons of biofuel by 2022. One of the biggest hurdles to achieving this goal lies in optimizing the multistep process involved in breaking down plant biomass and then converting it into fermentable sugars that can be refined into fuel for our transportation needs. To overcome this challenge, the U.S. Department of Energy supports several projects focused on identifying enzymes from fungi and microbes such as cellulasesthat breakdown plant cell wallsand heat-tolerant industrial-strength host cell systems to drive these reactions.
Many of the cellulases currently used in biofuel production are derived from species that thrive at temperatures of 20C-35C (68F-95F) which is room temperature to nearly body temperature. The conversion process at these temperatures takes time, during which contaminants can reduce the final yield. To speed up the conversion process, researchers propose raising the temperature, which in turn requires enzymes that are stable above current working conditions. They now appear to be on the right track.
Published online October 2 in Nature Biotechnology, an international team of scientists including DOE JGI researchers compared the finished genomes of Thielavia terrestris and Muceliophthora thermophila, fungi that thrive in high-temperature environments above 45C and whose enzymes, active at temperatures ranging from 40 C to 75 C, would therefore be useful for accelerating (thus improving) the biofuel production process.
"Thermostable enzymes and thermophilic cell factories may afford economic advantages in the production of many chemicals and biomass-based fuels," wrote the team that includes DOE JGI Fungal Genomics head Igor Grigoriev as well as longtime collaborators Randy Berka from Novozymes in Davis, Calif. and Adrian Tsang of Concordia University in Canada. As these published genomes represent the first
|Contact: David Gilbert|
DOE/Joint Genome Institute