Mascoma Corp is one of the two cellulosic ethanol companies that
General Motors invested in earlier this year
is one of Mascoma's co-founders and he and his collaborators at Dartmouth College have published a paper that gives some more insight into Mascoma's process. They have created a new genetically-engineered bacteria aimed at producing ethanol from biomass. The key to this new microbe is its ability to function at higher temperatures than the naturally-occurring types that have been used previously. The natural bacteria can't function at temperatures above 37°C and require a significant amount of cellulase enzyme which greatly increases the cost of the process. By operating at temperatures above 50°C, the new microbe requires only 40 percent of the amount of cellulase. The natural bacteria also produce another by-product besides ethanol, organic acids. The resulting output then needs further processing to separate the alcohol from the acid. The genetically-engineered microbes apparently produce no acids, with the fuel being the only product.