Microbial Genomics Group, Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359 Bremen, Germany. mrichter@mpi-bremen.de|Microbial Genomics Group, Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359 Bremen, Germany. mrichter@mpi-bremen.de|Microbial Genomics Group, Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359 Bremen, Germany. mrichter@mpi-bremen.de|Microbial Genomics Group, Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359 Bremen, Germany. mrichter@mpi-bremen.de|Microbial Genomics Group, Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359 Bremen, Germany. mrichter@mpi-bremen.de|Microbial Genomics Group, Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359 Bremen, Germany. mrichter@mpi-bremen.de|Microbial Genomics Group, Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359 Bremen, Germany. mrichter@mpi-bremen.de