Abstract
A new family, the Comamonadaceae, is proposed for the organisms belonging to the acidovorans rRNA complex in the beta subclass of the Proteobacteria. This family includes the genera Comamonas, Acidovorax, Hydrogenophaga, Xylophilus, and Variovorax (formerly Alcaligenes paradoxus), as well as a number of phylogenetically misnamed Aquaspirillum and phytopathogenic Pseudomonas species.