1. NIOZ, Royal Netherlands Institute for Sea Research, Department of Marine Microbiology and Biogeochemistry, and Utrecht University, P.O. Box 59, NL-1790 AB Den Burg, The Netherlands
2. Department of Marine Science, University of Texas at Austin, Marine Science Institute, 750 Channel View Drive, Port Aransas, TX 78373, USA
3. Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, P.O. Box 596, Husargatan 3, SE-75123 Uppsala, Sweden
4. School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol, Bristol BS8 1TQ, UK