Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
           Domain Bacteria Woese et al. 2024
             Kingdom Pseudomonadati (Gibbons and Murray 1978) Oren and Göker 2024
               Phylum Pseudomonadotaᵀ Garrity et al. 2021
                 Class Betaproteobacteria Garrity et al. 2006
                   Order Burkholderialesᵀ Garrity et al. 2006
                     Family Comamonadaceae Willems et al. 1991
                       Genus Hydrogenophaga Willems et al. 1989
                         1 Hydrogenophaga atypica Kämpfer et al. 2005
                         2 Hydrogenophaga bisanensis Yoon et al. 2008
                         3 Hydrogenophaga caeni Chung et al. 2007
                         4 Hydrogenophaga defluvii Kämpfer et al. 2005
                         5 Hydrogenophaga flava (Niklewski 1910) Willems et al. 1989
                         6 Hydrogenophaga intermedia Contzen et al. 2001
                         7 Hydrogenophaga palleronii (Davis 1970) Willems et al. 1989
                         8 Hydrogenophaga pseudoflava (Auling et al. 1978) Willems et al. 1989
                         9 Hydrogenophaga taeniospiralis (Lalucat et al. 1982) Willems et al. 1989