1. Max-Planck-Institute for Terrestrial Microbiology; Karl-von-Frisch-Straße 10 Marburg D-35043 Germany
2. Laboratory of Microbial Ecology and Technology (LabMET); Ghent University; Coupure Links 653 Ghent 9000 Belgium
3. Microbial Ecophysiology; Faculty of Biology/Chemistry; University of Bremen; Bremen D-28334 Germany