1. Department of Hydrology, BayCEER, University of Bayreuth, Bayreuth, Germany;
2. Geomicrobiology Group, Eberhard-Karls-University Tuebingen, Tuebingen, Germany;
3. Earth System Science, Stanford University, Stanford, CA, USA;
4. Institute of Landscape Ecology (ILoek), Ecohydrology and Biogeochemistry Group, University of Muenster, Muenster, Germany;
5. Institute of Microbiology, Leibniz University Hannover, Hannover, Germany;
6. Department of Isotope Biogeochemistry, Helmholtz-Centre for Environmental Research UFZ, Leipzig, Germany;
7. Environmental Geochemistry Group, BayCEER, University of Bayreuth, Bayreuth, Germany