USDA ARS Researchers Focus on Boosting Cellulosic Biofuel Yields

The Agricultural Research Service's Bioenergy Research Unit in Peoria has been focused on studies involving the feedstock switchgrass.

Chemical engineer Bruce Dien evaluated two different switchgrass varieties harvested at three different points in plant development and then pretreated with diluted ammonia. Chemist Michael Bowman led a separate study that focused on xylan levels at three different stages in switchgrass development to see if xylan structures change as the plant matures.

In another study, molecular biologist Ron Hector determined the microorganisms needed to convert xylose to ethanol. Scientists already know that the enzyme "D-xylose isomerase," or XI, is one of several enzymes required to convert xylose into ethanol. But, to date, it has been difficult to harness XI's conversion potential due to the difficulty of expressing XI in yeast strains.