Natura - nature actualia - actual entities Mundus Plinius - physical world naturalia - natural bodies [crown] Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020] Domain Bacteria Woese et al. 1990 [paraphyletic?] Superphylum "Proteobacteria" Craig et al. 2010 Phylum "Alphaproteobacteria" Garrity et al., 2006 [monotypic] Class Alphaproteobacteriaᵀ Garrity et al. 2006 Order Rhizobiales Kuykendall 2006 Family Bradyrhizobiaceae Garrity et al. 2006 Genus Nitrobacter Winogradsky 1892 (Approved Lists 1980) Nitrobacter winogradskyi Winslow et al. 1917 (Approved Lists 1980)