Affiliation: | From the ‡Department of General Microbiology, Georg-August-University Göttingen, Grisebachstrasse 8, D-37077 Göttingen, Germany and ¶Interfaculty Institute for Genetics and Functional Genomics, Ernst-Moritz-Arndt-University Greifswald, Friedrich-Ludwig-Jahnstrasse 15a, D-17487 Greifswald, Germany |