[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Domain Bacteria Woese et al. 1990 stat. inval. see Domain Bacteria Woese et al. 2024
     Phylum "Proteobacteria" Garrity et al. 2005 stat. inval. see Phylum Pseudomonadota Garrity et al. 2021
       Class Gammaproteobacteria Garrity et al. 2005
         Order Chromatiales Imhoff 2005
           Family Chromatiaceae Bavendamm 1924 (Approved Lists 1980)
             Genus Nitrosococcus Winogradsky 1892 nom. cons. (Approved Lists 1980)
               Nitrosococcus nitrosus (Migula 1900) Buchanan 1925 (Approved Lists 1980)