1. National Bioenergy Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States
2. Department of Chemical Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
3. Renewable and Sustainable Energy Institute, University of Colorado at Boulder, Boulder, Colorado 80309, United States
4. Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States
5. Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
6. Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States