prokaryotes - bacteria see Domain Bacteria Woese et al. 1990
   Domain "Bacteria" Woese et al. 1990
     Phylum "Proteobacteria" Garrity et al. 2005 see Superphylum Proteobacteria Craig et al. 2010
       Class Betaproteobacteria Garrity et al. 2006
         Order Nitrosomonadales Garrity et al. 2006
           Family Nitrosomonadaceae Garrity et al. 2006
             1 Genus Nitrosolobus Watson et al. 1971 (Approved Lists 1980) see Genus Nitrosospira Winogradsky and Winogradsky 1933 (Approved Lists 1980)
             2 Genus Nitrosomonas Winogradsky 1892 (Approved Lists 1980)
             3 Genus Nitrosospira Winogradsky and Winogradsky 1933 (Approved Lists 1980)