Strictly
anaerobic archaebacteria, able to use only a very limited substrate spectrum (e.g. molecular
hydrogen, formate, methanol, methylamine, carbon monoxide or acetate) as electron
donors for the reduction of carbon dioxide to methane.
Source:
PAC, 1992, 64, 143
(Glossary for chemists of terms used in biotechnology (IUPAC Recommendations 1992))
on page 160