Spore-forming sulfate-reducing bacteria, previously assigned to the genus Desulfotomaculum, are typical inhabitants of thermal groundwater biotopes (Aüllo et al., 2013; Frank et al., 2016). Due to their ability to form spores, to grow autotrophically, and to survive high temperatures, this group is a successful colonizer of groundwaters. Revision of the genus Desulfotomaculum resulted in description of four new genera, Desulfallas, Desulfofundulus, Desulfofarcimen, and Desulfohalotomaculum (Watanabe et al., 2018)