A team of researchers from Dartmouth's Thayer School of Engineering and Mascoma Corporation in Lebanon, N.H., have made a discovery that is important for producing large quantities of cellulosic ethanol, a leading candidate for a sustainable and secure alternative to petroleum-derived transportation fuel. For the first time, the group has genetically engineered a thermophilic bacterium, meaning it's able to grow at high temperatures, and this new microorganism makes ethanol as the only product of its fermentation.