Procaryotic Genera Domain "Bacteria" Woese et al. 1990 Phylum Proteobacteria Garrity and Holt 2001 see Phylum Proteobacteria Garrity et al. 2005 Class "Alphaproteobacteria" Garrity and Holt 2001 nom. nud. see Class Alphaproteobacteria Garrity et al. 2006 Order "Sphingomonadales" [monotypic] see Order Sphingomonadales Yabuuchi and Kosako 2006 1 Family Sphingomonadaceae Kosako et al. 2000