41. Moreover, these methanogens change the structure of the tailings pond and help the pore water efflux to reuse for processing oil sands. 42. There are over 50 described species of methanogens , which do not form a monophyletic group, although all methanogens belong to Archaea. 43. There are over 50 described species of methanogens, which do not form a monophyletic group, although all methanogens belong to Archaea. 44. Many microorganisms affect anaerobic digestion, including acetic acid-forming bacteria ( acetogens ) and methane-forming archaea ( methanogens ). 45. This is supported by the presence of 10 conserved signature proteins that are uniquely found in all methanogens and " Archaeoglobus ". 46. This process affects the carbon cycle : methanogens can participate in interspecies hydrogen transfer combining H 2 and CO 2 to produce CH 4. 47. An exception to this wide distribution is a group of unique cofactors that evolved in methanogens , which are restricted to this group of archaea. 48. Some methanogens , called hydrogenotrophic, use carbon dioxide ( CO 2 ) as a source of carbon, and hydrogen as a reducing agent. 49. Additionally, 10 proteins found in all methanogens which are shared by " Archaeoglobus ", suggest that these two groups are related. 50. Little is understood about the function of these " class IV " " nif " genes, though they occur in many methanogens .
