Goal: Convert sugars to ethanol using microbes. Microbes ferment sugars to ethanol, which is then separated from the mix of ethanol, water, microbes, and residue and purified through distillation.
[Some images taken from "Genomics:GTL Transforming Cellulosic Biomass," U.S. Department of Energy Office of Science and Office of Energy Efficiency and Renewable Energy, June 2006, genomicscience.energy.gov/biofuels/ and U.S. DOE. 2006. "Breaking the Biological Barriers to Cellulosic Ethanol: A Joint Research Agenda," DOE/SC/EE-0095, U.S. Department of Energy Office of Science and Office of Energy Efficiency and Renewable Energy, genomicscience.energy.gov/biofuels/.]
Credit or Source: Office of Biological and Environmental Research of the U.S. Department of Energy Office of Science. science.energy.gov/ber/
US DOE. May 2007. Biofuels Primer Placemat: From Biomass to Cellulosic Ethanol and Understanding Biomass: Plant Cell Walls, US Department of Energy Office of Science. (website)