Type (and only) species : Rikenella microfusus.
Characterisitcs of the species: Ferments glucose, mannos, lactose, and melibiose, and sometimes galactose: growth is improved by the presence of carbohydrate. Strains are B-hemolytic, liquefy gelatin,and grow well in the presence of 20% bile. Produces propionic and succinic acids, but not butyric or lactic acids.