Procaryotic Genera Domain "Bacteria" Woese et al. 1990 Phylum Actinobacteria Garrity and Holt 2001 [monotypic] Class Actinobacteria Stackebrandt et al. 1997 Subclass Actinobacteridae Stackebrandt et al. 1997 see Class Actinobacteria Stackebrandt et al. 1997 Order Bifidobacteriales Stackebrandt et al. 1997 1 Family Bifidobacteriaceae Stackebrandt et al. 1997 2 Family Unknown Affiliation