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
                     Family Alcaligenaceae De Ley et al. 1986
                       Genus Alcaligenesᵀ Castellani and Chalmers 1919 (Approved Lists 1980)
                         Alcaligenes faecalisᵀ Castellani and Chalmers 1919 (Approved Lists 1980)
                           1 Alcaligenes faecalis subsp. faecalisᵀ (Castellani and Chalmers 1919) Austin et al. 1981
                           2 Alcaligenes faecalis subsp. parafaecalis Schroll et al. 2001
                           3 Alcaligenes faecalis subsp. phenolicus Rehfuss and Urban 2006