ammonifex degensii ammonifex degensii ammonifex degensii is a gram-negative bacterium from the genus of ammonifex which has been isolated from a volcanic hot spring from the kawah candradimuka crater, dieng plateau, java, indonesia. ammonifex degensii scientific classification domain: bacteria phylum: bacillota order: thermoanaerobacterales family: thermoanaerobacteraceae genus: ammonifex species: a. degensii binomial name ammonifex degensiihuber and stetter 1996 type strain dsm 10501, kc4