1. Deconstruction Division, Joint BioEnergy Institute, 5885 Hollis Street, Emeryville, California 94608, USA
2. Department of Biomass Science and Conversion Technology, Sandia National Laboratories, 7011 East Avenue, Livermore, California 94551, USA
3. Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
4. Key Laboratory of Forestry Genetics & Biotechnology (Nanjing Forestry University), Ministry of Education, Nanjing 210037, People's Republic of China