Cellulosic Ethanol Progress from Mascoma

Mascoma presented new information on its "one-step process" for producing ethanol from cellulosic biomass at the 31st Symposium on Biotechnology for Fuels and Chemicals in San Francisco recently. Mascoma saves on enzyme costs by using engineered organisms, Clostridium thermocellum, that produce their own cellulase enzymes for breaking down cellulose.

Pre-treatment opens up the structure of the biomass by disrupting the lignin seal and exposing cellulosic plant cell wall components. This gives the CBP microorganisms—which generate the enzymes to hydrolyze cellulose into fermentable sugars and also ferment the sugars to ethanol—access to the cellulosic constituents.

This one-step conversion process lowers costs by limiting additives and enzymes used in other biochemical processes.

Mascoma is combining naturally occurring metabolic activities in single microorganisms by modifying the fermentative pathways of the most efficient processors of cellulose, including the thermophilic anaerobic bacterium Clostridium thermocellum, to produce high yields of ethanol from hardwoods and other biomass. _GCC

The ethanol can be continuously siphoned off, and fresh biomass and organisms can be continuously added to the bioreactors as needed. Waste products -- both liquid and solid -- can be passed on to further processes or sold as feedstock for gasification, pyrolysis, torrefaction, pelletisation, anaerobic fermentation to methane, etc etc etc.

The infrastructure for bioenergy will take time to develop, just as the infrastructure for coal, natural gas, and liquid petroleum products developed over time. The key concept is "local and regional." No magic bullets. Just local and regional solutions.