procaryotes Domain Bacteria Woese et al. 1990 Phylum Aquificae Reysenbach 2001 Class Aquificae Reysenbach 2001 nom. inval. see Class Aquificae Reysenbach 2002 Order Aquificales Reysenbach 2001 nom. inval. see Order Aquificales Reysenbach 2002 1 Family Aquificaceae Reysenbach 2001 nom. inval. see Family Aquificaceae Reysenbach 2002 2 Genus Desulfurobacterium L'Haridon et al. 1998