1. German Aerospace Center (DLR e.V.), Institute of Aerospace Medicine, Radiation Biology Department, Space Microbiology Research Group, Cologne, Germany
2. Chemical, Biological and Radiological Division, Defense Science and Technology Laboratory (Dstl), Porton Down, Salisbury, Wiltshire, United Kingdom
3. Department of General Microbiology, Institute for Microbiology and Genetics, Georg-August-University Göttingen, Göttingen, Germany
4. Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, Connecticut, USA