1. Department of Biochemistry and Synthetic Metabolism, Max Planck Institute for Terrestrial Microbiology, D-35043 Marburg, Germany.
2. University of Bordeaux, CNRS, Centre de Recherche Paul Pascal, UMR 5031, Pessac 33600, France.
3. Institut Universitaire de France, Paris 75005, France.
4. Center for Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology, D-35043 Marburg, Germany.