Assignment of Clostridium bryantii to Syntrophospora bryantii gen. nov., comb. nov. on the basis of a 16S rRNA sequence analysis of its crotonate-grown pure culture.

The Clostridium bryantii-Methanospirillum hungatei syntrophic coculture, grown on caproate, was adapted to grow on crotonate. Then, C. bryantii was isolated in pure culture from crotonate bottle plates. A 16S rRNA sequence analysis of the pure subculture revealed that, as a member of the gram-positive phylum, it was not closely related to any of the Clostridium species with which it was compared or to any of the other clusters in the gram-positive phylum with which it was compared. However, it was closely related to another syntrophic fatty acid-degrading bacterium, Syntrophomonas wolfei. On the basis of its phylogeny, physiology, and cell wall ultrastructure, we propose assignment of C. bryantii to Syntrophospora bryantii gen. nov., nov. comb.