UGA Researchers Develop Super Yeast that Turns Pine into Ethanol

(University of Georgia/Ethanol Producer Magazine) Researchers at the University of Georgia have developed a "super strain" of yeast that can efficiently ferment ethanol from pretreated pine, one of the most common species of trees in Georgia and the U.S. Their research could help biofuels replace gasoline as a transportation fuel.

Before the pinewood is fermented with yeast, however, it is pre-treated with heat and chemicals, which help open the wood for enzymes to break the cellulose down into sugars. Once sugars are released, the yeast will convert them to ethanol, but compounds produced during pretreatment tend to kill even the hardiest industrial strains of yeast, making ethanol production difficult.

Doran-Peterson, along with doctoral candidate G. Matt Hawkins, used directed evolution and adaptation of Saccharomyces cerevisiae, a species of yeast used commonly in industry for production of corn ethanol, to generate the "super" yeast.

Their research, published online in Biotechnology for Biofuels, shows that the pine fermented with the new yeast can successfully withstand the toxic compounds and produce ethanol from higher concentrations of pretreated pine than previously published.

The loblolly pine that Doran-Peterson and Hawkins used for their research is among the fastest growing trees in the American South.

"We're talking about using forestry residues, waste and unsalable timber," said Peterson, "Alternatively, pine forests are managed for timber and paper manufacturing, so there is an existing infrastructure to handle tree-farming, harvest and transportation for processing.

"The basic idea is that we're trying to get the yeast to make as much ethanol as it can, as fast as it can, while minimizing costs associated with cleaning or washing the pretreated pine. With our process, no additional clean-up steps are required before the pine is fermented," she said. READ MORE Abstract (Biotechnology for Biofuels)