Although cellulosic biomass such as corn stover, wheat straw and bagasse (the fibrous remains after sugar is extracted from sugarcane or sorghum) is abundant and cheap, because of recalcitrance -- a plant's resistance to releasing sugars for conversion to alcohol -- it is much more difficult to utilize than corn. However, Mascoma's new strain of yeast, which is one of many strains Mascoma developed as part of BESC over the last two years, proved highly effective at xylose conversion.
While most processing methods simply convert cellulose to sugar, this new approach also converts hemicellulose, which significantly increases overall sugar yield and thereby increases the level of ethanol produced. In fact, the new strain of yeast simultaneously yields 97 percent conversion of xylose and glucose -- and does so in a significantly shorter period of time than existing approaches.
Kevin Wenger, executive vice president of Mascoma, a subsidiary of Lallemand Inc., shares Gilna's enthusiasm and emphasized that the BESC model of collaboration made this result possible.
"The scientific and technical resources that we have had access to as a member of BESC for the past six years have made possible the development of this uniquely high-performing yeast product," Wenger said. "This is just the start of a pipeline of second-generation yeast products planned by Mascoma and Lallemand Biofuels and Distilled Spirits."
The next step for BESC will be to demonstrate and again validate the application of the consolidated bioprocessing approach using thermophilic, or heat-loving, bacteria to produce biofuels directly from biomass in a single process.