Transfer of the Nitrogen-Fixing Hydrogen Bacterium Corynebacterium autotrophicum Baumgarten et al. to Xanthobacter gen. nov.

Abstract
Thirty-five nitrogen-fixing, hydrogen-oxidizing bacteria, all members of Cory-nebacterium autotrophicum Baumgarten, Reh, and Schlegel 1974, and including the type strain of this species, were compared with 28 strains of coryneform bacteria by numerical taxonomy methods. The nitrogen-fixing hydrogen bacteria formed a well defined cluster; their similarity to the other strains tested was low, however. Furthermore, the chemotaxonomic characters of these strains excluded them from the coryneform bacteria. Therefore C. autotrophicum was reclassified, following the keys of Bergey's Manual of Determinative Bacteriology (8th ed.) as a species of the family Azotobacteraceae. Although taxonomically close to Beijerinckia and Derxia, the nitrogen-fixing, hydrogen-oxidizing bacteria are regarded as representing a new genus, for which we propose the name Xanthobacter. C. autotrophicum Baumgarten, Reh, and Schlegel is transferred to the new genus as Xanthobacter autotrophicus (Baumgarten et al.) comb. nov.