1. Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
2. Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, Wisconsin 53726, USA
3. Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin 53726, USA
4. Andlinger Center for Energy and the Environment, Princeton University, Princeton, NJ, 08544, USA
5. Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, USA
6. Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53726, USA
7. Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA