Methanogen

A methanogen is an archaeum, a microorganism that produces methane from the reaction of hydrogen and carbon dioxide.

There are two categories of methanogens: 1) Hydrogenotrophic; and 2) Acetotrophic. Methanogens belong to the archaebacteria and differ from prokaryotes: 1)cell wall composition eg. lack muramic acid; 2) specific co-enzyme F420 which acts as an electron carrier in metabolism; and 3) rRNA sequences are different. There are three orders: 1)Methanobacteriales; 2)Methanomicrobiales; and 3)Methanococcals.

- more than 50 species - standard microbial techniques are not suitable for isolating methanogens - fastidious and occur as consortia - difficult to culture - immunological analysis required

Methanogens are one of the several possible explanations for the recently discovered presence of methane on Mars.