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 "Nitrosomonadales" see Order Nitrosomonadales Garrity et al. 2006 Family "Nitrosomonadaceae" see Family Nitrosomonadaceae Garrity et al. 2006 Genus Nitrosospira Winogradsky and Winogradsky 1933 (Approved Lists 1980) 1 Genus Nitrosomonas Winogradsky 1892 (Approved Lists 1980)