1. Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research, Permoserstrasse 15, D-04318 Leipzig, Germany, Department of Bioremediation, Helmholtz Centre for Environmental Research, Permoserstrasse 15, D-04318 Leipzig, Germany, Center for Applied Geoscience, Working Group Hydrogeochemistry, Eberhard-Karls-University of Tuebingen, Sigwartstrasse 10, D-72076 Tuebingen, Germany, Department of Environmental Microbiology, Helmholtz Centre for Environmental Research, Permoserstrasse 15,...