1. School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
2. Center for Bioinformatics and Computational Genomics, Georgia Institute of Technology, Atlanta, Georgia, USA
3. School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
4. U.S. Department of Energy, Joint Genome Institute, Walnut Creek, California, USA
5. Center for Microbial Ecology, Michigan State University, East Lansing, Michigan, USA
6. Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, Michigan, USA
7. Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA