1. 1BioDiscovery Institute and Department of Biological Sciences, University of North Texas, Denton, Texas, USA; email: Richard.Dixon@unt.edu
2. 2Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
3. 3Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, Colorado, USA
4. 4Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA