Many of the enzymes currently being used in the pretreatment processes for cellulosic biofuels production come from species that thrive at temperatures comfortable to humans (68°F-95°F).
To speed up this process of converting polysaccharides to fermentable sugars, a goal driven by the nation’s Renewable Fuels Standard requirement that calls for the annual production of 36 billion gallons of biofuelby 2022, researchers propose raising the temperature of the reaction. This proposed change in the process in turn requires enzymes from species that can tolerate hotter environments.
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Thermophilic fungus M. thermophila
(Micrograph by Ronald de Vries, CBS-KNAW Fungal Biodiversity Centre. Image enhanced by Michelle Wyse)
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In a report published online October 2, 2011 in Nature Biotechnology, an international team of scientists including DOE JGI researchers and longtime collaborators from industry and academia compared the finished genomes of Thielavia terrestris and Myceliophthora thermophila, filamentous fungi that thrive in high-temperature environments above 45°C.
The 38.7-million base pair (Mbp) genome of M. thermophila and the 36.9 Mbp genome of T. terrestris were sequenced using Sanger technology at the DOE JGI, and the researchers believe the enzymes of these fungi, active at temperatures ranging from 40°C to 75°C, would therefore be useful for accelerating the biofuel production process.
“These sequences open the way for new industrial applications of the enzymes from these organisms and potential development of thermophilic fungal production hosts,” wrote the team including DOE JGI Fungal Genomics Head Igor Grigoriev in their paper.
More information is available in the DOE JGI release regarding this study.