thermohydrogenium thermohydrogenium thermohydrogenium is an anaerobic and thermophilic bacterial genus from the family of syntrophomonadaceae with one known species (thermohydrogenium kirishiense). thermohydrogenium scientific classification domain: bacteria phylum: bacillota class: clostridia order: eubacteriales family: syntrophomonadaceae genus: thermohydrogeniumzacharova et al. 1996 type species thermohydrogenium kirishiense species t. kirishiens