PHOTO: USDA AGRICULTURAL RESEARCH SERVICE
research
Left to right: NCAUR scientists Cotta, Hector, Hughes, Liang-Li and Rich
form and creating the automated molecular biology routines necessary to screen for the most effective set of enzymes. The genes for these enzymes may exist in organisms contained in the ARS culture collection and from organisms isolated from environments such as cattle rumen, hot springs, termite guts and ocean thermal vents. Sookie Bang at the Center for
Bioprocessing Research and Development located at the South Dakota School of Mines and Technology is isolating extremeophiles from the National Science Foundation-sponsored Deep Underground Science and Engineering Laboratory as a source of novel enzymes that have been selected for more than 125 years at temperatures in excess of 140 degrees Fahrenheit
in the harsh deep-mine conditions. These enzymes hold great promise for use in producing lignocellulose-degrading yeast strains. Assuming appropriate enzymes are identified, a critical question remains. Is S. cerevisiae capable of simultaneously expressing the genes for all the different enzymes necessary to hydrolyze cellulose and hemicellulose as well as ferment pentose sugars? Indications are increasing that ethanol production by an ethanologen that has the ability to efficiently hydrolyze pretreated biomass and metabolize the resulting sugars is feasible. However, says Michael Cotta, leader of the Fermentation Biotechnology Research Unit at NCAUR, “Considerable research and development are still needed to develop the optimum enzymes, organisms and processes that will be able to generate a sustainable biomass to ethanol process.” BIO Ronald Hector, Stephen Hughes and Xin Liang-Li are research molecular biologists with the USDA’s Agricultural Research Service. Reach Hector at Ronald.hector @ars.usda.gov or (309) 681-6098. Reach Hughes at Stephen.hughes@ars.usda.gov or (309) 681-6176. Reach Liang-Li at shin.li @ars.usda.gov or (309) 681-6327.
4|2008 BIOMASS MAGAZINE 85