Abstract
* Corresponding author. Mailing address: DSM-German Collection of Microorganisms and Cell Cultures GmbH. Mascheroder Weg 1b, 38124 Braunschweig, Germany. Phone: 49 531 2616 352. Fax: 49 531 2616 418. Electronic mail address: stackebrandt{at}venus.gbf-braunschweig.d400.de .