1. Centre d'Estudis Avançats de Blanes (CEAB); CSIC; Accés a la Cala Sant Francesc 14 17300 Blanes Spain
2. Laboratory of Microbiology; Wageningen University; Dreijenplein 10 6703 HB Wageningen The Netherlands
3. Institute of Water Research; Department of Microbiology; University of Granada; c/Ramon y Cajal 4 18071 Granada Spain
4. Molecular Microbial Ecology Group; University of Copenhagen; Sølvgade 83H 1307K Copenhagen Denmark