Domain Bacteria Woese et al. 1990
   Phylum Proteobacteria Garrity and Holt 2001 see Phylum Proteobacteria Garrity et al. 2005
     Class "Betaproteobacteria" Garrity et al. 2001 nom. ined. see Class Betaproteobacteria Garrity et al. 2006
       Order "Burkholderiales" see Order Burkholderiales Garrity et al. 2006
         Family Alcaligenaceae De Ley et al. 1986
           Genus Alcaligenes Castellani and Chalmers 1919 (Approved Lists 1980)