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" see Order Sphingomonadales Yabuuchi and Kosako 2006 Family "Sphingomonadaceae" Kosako et al. 2000 Genus Blastomonas Sly and Cahill 1997 Genus Erythrobacter Shiba and Simidu 1982 Genus Erythromicrobium Yurkov et al. 1994 Genus Erythromonas Yurkov et al. 1997 see Genus Blastomonas Sly and Cahill 1997 Genus Porphyrobacter Fuerst et al. 1993 Genus Rhizomonas van Bruggen et al. 1990 Genus Sandaracinobacter Yurkov et al. 1997 Genus Zymomonas Kluyver and van Niel 1936 (Approved Lists 1980) 1 Genus Sphingomonas Yabuuchi et al. 1990