1. Department of Genetics, Biology of Microorganisms, Anthropology, Evolution, University of Parma, Parma, Italy
2. Alimentary Pharmabiotic Centre and Department of Microbiology, National University of Ireland, Cork, Ireland
3. Institute for Genome Research and Systems Biology Center for Biotechnology, Bielefeld University, Universitaetsstrasse 25, D-33615 Bielefeld, Germany
4. Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Colney, Norwich, United Kingdom