MADISON - A collaborative research project between the U.S. Forest Service Forest Products Laboratory (FPL) and the Department of Energy Joint Genome Institute has advanced the quest for efficient conversion of plant biomass to fuels and chemicals.
"We have sequenced and assembled the complete genome of Pichia stipitis, a native xylose-fermenting yeast," says Thomas Jeffries, research microbiologist at FPL and a professor of bacteriology at the University of Wisconsin-Madison. The results of this research project will be published in the scientific journal Nature Biotechnology in April, and the report is currently available online at http://www.nature.com/nbt/journal/vaop/ncurrent/index.html.
The sequencing of P. stipitis marks an important step toward the efficient production of biofuels because the yeast can efficiently ferment xylose, a main component of plant lignocellulose. Xylose fermentation is vital to economically converting plant biomass to fuels and chemicals such as ethanol.
"A better understanding of the genetic structure of this yeast allows us to determine how specific genes are used in fermentation and then reengineer them to perform other desired functions," says Jeffries.
For example, Jeffries explains that the fermentation of both glucose and xylose is critical to efficient bioconversion because xylose is so abundant in hardwoods and agricultural residues. However, when glucose is present, the fermentation of xylose by P. stipitis is repressed. Using their knowledge of the genetic makeup of the yeast, researchers will be able to alter the expression of the genes so that both glucose and xylose are fermented simultaneously. This will increase the efficiency, and improve the economic viability, of the process.
The U.S. Forest Service Forest Products Laboratory, with its mission to conserve and extend the country's wood resources, is a partn
Contact: Thomas Jeffries
University of Wisconsin-Madison