[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Domain Bacteria Woese et al. 1990
     Phylum "Aquificae" Reysenbach 2001
       Class "Aquificae" Reysenbach 2002
         Order Aquificales Reysenbach 2002
           Family Aquificaceae Reysenbach 2002
             Genus Hydrogenobacter Kawasumi et al. 1984
               1 Hydrogenobacter thermophilus Kawasumi et al. 1984
               2 Hydrogenobacter hydrogenophilus (Kryukov et al. 1984) Stöhr et al. 2001
               3 Hydrogenobacter subterraneus Takai et al. 2001