life see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Superkingdom Prokarya see Domain Bacteria Woese et al. 1990 stat. inval.
     Kingdom Bacteria Cavalier-Smith 1998 nom. inval. - bacteria see Kingdom Bacteria Cavalier-Smith 2002 stat. inval.
       Subkingdom Eubacteria Cavalier-Smith 1981 see Domain Bacteria Woese et al. 1990 stat. inval.
         Division Gracilicutes Gibbons and Murray 1978 (Approved Lists 1980) see Phylum Gracilicutes
           Phylum Proteobacteria Garrity and Holt 2001 nom. nud. see Phylum Proteobacteria Garrity et al. 2005 stat. inval.
             "Alpha Group" see Class Alphaproteobacteria Garrity et al. 2006
               01 Genus Agrobacterium Conn 1942 (Approved Lists 1980) nom. cons.
               02 Genus Aquaspirillum Hylemon et al. 1973 (Approved Lists 1980)
               03 Genus Beijerinckia Derx 1950 (Approved Lists 1980)
               04 Genus Nitrobacter Winogradsky 1892 (Approved Lists 1980) nom. cons.
               05 Genus Paracoccus Davis 1969 (Approved Lists 1980)
               07 Genus Rhizobium Frank 1889 (Approved Lists 1980) nom. cons.
               08 Genus Rhodobacter Imhoff et al. 1984
               09 Genus Rhodopseudomonas Czurda and Maresch 1937 (Approved Lists 1980) nom. cons.
               10 Genus Rhodospirillum Molisch 1907 (Approved Lists 1980)
               13 "Budding Bacteria" see Family Hyphomicrobiaceae Babudieri 1950 (Approved Lists 1980)