1. Center for Astronomy and Astrophysics (ZAA), Astrobiology Research Group, Technische Universität Berlin, Berlin, Germany.
2. German Research Centre for Geosciences (GFZ), Section Geomicrobiology, Potsdam, Germany.
3. Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Stechlin, Germany.
4. School of the Environment, Washington State University, Pullman, WA, USA.