1. Faculty of Biology; Philipps-Universität; Marburg 35043 Germany
2. Max Planck Institute for Terrestrial Microbiology; Marburg 35043 Germany
3. Division of Biology and Bioengineering; California Institute of Technology; Pasadena CA 91125 USA
4. Faculty of Chemistry; Philipps-Universität; Marburg Germany
5. Howard Hughes Medical Institute, California Institute of Technology; Pasadena CA 91125 USA
6. LOEWE Center for Synthetic Microbiology; Marburg 35043 Germany