Genomes have recently been obtained for this previously uncharacterised genus which is now known as "Ca. Methanofastidiosa" 1. Genome analyses indicate a lack of potential for CO2 and nitrogen fixation. Acetate, propionate and malonate are suggested to be potential carbon sources for growth. All genomes lack genes for acetoclastic and C02-reducing methanogenesis and it is suggested that they are restricted to methylated thiol reduction for methane generation 1. Although MiDAS and SILVA include this in the class Thermoplasmata, Nobu et al., provide evidence that it should be placed into a novel class named Methanofastidiosa 1. This will be addressed in future MiDAS releases.
 Nobu, Narihiro, Kuroda, Mei, Liu (2016): Chasing the elusive Euryarchaeota class WSA2: genomes reveal a uniquely fastidious methyl-reducing methanogen. ISME J 10(10): 2478-87. doi:10.1038/ismej.2016.33