1. Centre for Ecology and Evolution in Microbial model Systems - EEMiS; Linnaeus University; SE-39182; Kalmar; Sweden
2. Department of Molecular Biology; Umeå University; SE-901 87; Umeå; Sweden
3. Department of Marine Sciences; University of Georgia; Athens; GA 30602; USA
4. Department of Microbiology; University of La Laguna; ES-38206; La Laguna; Tenerife; Spain