1. Max-Planck-Institute für terrestrische Mikrobiologie; Department of Ecophysiology; 35043 Marburg Germany
2. Biochemistry Department; University of Oxford; Oxford OX1 3QU UK
3. Justus-Liebig-Universität Gießen; Department of Microbiology and Molecular Biology at the IFZ; Gießen 35392 Germany
4. Physics Department; University of Oxford; Oxford OX1 3QU UK