[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Domain Bacteria Woese et al. 1990
     Phylum "Proteobacteria" Garrity et al. 2005 see Superphylum Proteobacteria Craig et al. 2010
       Class Gammaproteobacteria Garrity et al. 2005
         Order Chromatiales Imhoff 2005
           Family Chromatiaceae Bavendamm 1924 (Approved Lists 1980)
             Genus Chromatium Perty 1852 (Approved Lists 1980)
               Chromatium okenii (Ehrenberg 1838) Perty 1852 (Approved Lists 1980)