noun

• A methane-producing bacterium, especially an archaean which reduces carbon dioxide to methane.

  ‘Dog feces naturally contain bacteria called methanogens, which use hydrogen to break down carbon dioxide into microbial food.’

  More example sentences

  • ‘Methane is formed by a unique group of anaerobic bacteria belonging to the Archaea, the methanogens.’
  • ‘Since the discovery that methanogens belong to the Archaea and not to the Bacteria, a number of other archaeal groups have been discovered.’
  • ‘In this regard, both the phylogeny and function of archaeal selenoproteins are consistent with the argument that the archaeal ancestor was a methanogen.’
  • ‘Among the archaebacteria, the genome that is most similar to yeast at all thresholds is that of the methanogen Methanosarcina mazei.’