1 Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute of Sea Research and University of Utrecht, PO Box 59, 1790 AB Den Burg, The Netherlands.
2 Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road, New Brunswick, New Jersey 08901, USA.
3 Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Marítim de la Barceloneta 37-49, 08003 Barcelona, Spain.
4 Department of Biology and Environmental Science, Center of Ecology and Evolution in Microbial model Systems (EEMiS), Linnæeus University, 39182 Kalmar, Sweden.