Enzymes improve biofuel production efficiency

By JOHN O'CONNELL

Capital Press

Idaho National Laboratory researchers have isolated a suite of enzymes -- derived from a microorganism found in a Yellowstone National Park hot spring -- intended to make production of biofuels more economical.

David Reed, an INL staff scientist who has taken a lead role in the $14 million project, said six patents have been issued on enzymes capable of withstanding extreme conditions. The enzymes will work in concert to convert plant biomass into simple sugars for biofuel production.

Patents are pending for several other enzymes, which will be added to the suite to improve its effectiveness.

The common method of biofuel production involves heating the feed stock to hundreds of degrees under high pressure and adding acid to assist in the decomposition of cellulose.

The INL enzymes could cut production costs by reducing temperatures, pressure, waste and wear on equipment. With the heat- and acid-tolerant enzymes added to help conversion, the INL process makes biofuels effectively at temperatures as low as 170 degrees, still too hot for other enzymes to survive.

The microbe that was the basis of the 15-member INL team's research, Alicyclobacillus acidocaldarius, was discovered in 1971 by microbiologist Thomas Brock in the thermal waters of Yellowstone's Nymph Creek.

"We have taken this organism and taken its guts out, so to speak. We pulled it apart to look at what its enzymes do, and we have taken those enzymes and applied them to a process -- the production of ethanol," Reed said.

One of the enzymes developed by INL, Xtreme Xylanase, won the prestigious R&D 100 award in 2006. Reed describes it as "the most thermal- and acid-resilient enzyme of its kind."

INL is working with an industrial partner, Xtreme Biochemicals, seeking to commercialize the enzymes. Reed believes cost-effectively mass producing the enzymes poses a significant challenge toward using them in commercial production, though INL has made great progress toward that end lately.

The enzymes have been tested on corn stover, but Reed said rice hulls, straw, switchgrass and several other products would make good feed stocks. He said switchgrass can be grown on marginal farm land and could create a new cash crop for growers if technology can make it an efficient source of biofuels.

Tim Magnuson, an Idaho State University microbiology professor, is a member of a bioenergy research team with the Eastern Idaho-based Center for Advanced Energy Studies. His research has focused on converting dairy waste into biofuels using microorganisms the occur naturally in the manure. Magnuson believes the two approaches could be complementary.

"The more useful organisms, the better -- mix and match different organisms," Magnuson said. "The whole idea is to get more efficient breakdown and conversion of that material into biofuel."

On April 26, the European-based International Energy Agency's Tracking Clean Energy Progress report concluded global production of biofuels for transportation is insufficient to meet goals for curbing global climate change by 2020. The organization concluded global production of biofuels must double to meet their share of carbon dioxide reduction.