Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         [crown] Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
           Domain Bacteria Woese et al. 1990 [paraphyletic?]
             Superphylum "Proteobacteria" Craig et al. 2010
               Phylum "Betaproteobacteria" Garrity et al., 2006 [monotypic]
                 Class Betaproteobacteriaᵀ Garrity et al. 2006
                   Order Burkholderiales Garrity et al. 2006
                     Genus Aquabacterium Kalmbach et al. 1999, incertae sedis
                       1 Aquabacterium citratiphilum Kalmbach et al. 1999
                       2 Aquabacterium commune Kalmbach et al. 1999
                       3 Aquabacterium fontiphilum Lin et al. 2009
                       4 Aquabacterium limnoticum Chen et al. 2012
                       5 Aquabacterium parvum Kalmbach et al. 1999