1. Department of Microorganisms, Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures GmbH , Braunschweig D-38124 , Germany
2. Department of Bacteriology, University of Wisconsin-Madison , Madison, WI, 53706 , USA
3. Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna , Vienna A-1030 , Austria
4. Technical University of Braunschweig, Institute of Microbiology , Braunschweig D-38106 , Germany