Methane is generated biologically by methanogenic bacteria, a major division of the Archaea kingdom, largely from acetate dissimilation and carbon dioxide reduction. The latter pathway, as shown below, contains novel coenzymes and biochemical reactions not previously observed in other organisms. Methanogenesis is part of the C1 Metabolic Cycle.
The following is a text-format Methanogenesis pathway map. An organism which can initiate the pathway is given, but other organisms may also carry out later steps. Follow the links for more information on compounds or reactions. This map is also available in graphic (40k) format.
from the
Carbon Dioxide <------ C1 Metabolic Cycle
Methanobacterium
thermoautotrophicum
|
|
| formylmethanofuran
| dehydrogenase
|
|
v
Formylmethanofuran
|
|
| formylmethanofuran
| formyltransferase
|
|
v
N5-Formyl-5,6,7,8-tetrahydromethanopterin
|
|
| methenyl-H4MPT
| cyclohydrolase
|
|
v
N5,N10-methenyltetrahydromethanopterin
/ \
/ \
/ \
F420-dependent | | H(2)-dependent
methylene-H4MPT | | methylene-H4MPT
dehydrogenase | | dehydrogenase
\ /
\ /
v v
N5,N10-methylenetetrahydromethanopterin
|
|
| methylene-H4MPT
| reductase
|
|
v
5-Methyl-5,6,7,8-tetrahydromethanopterin
|
|
| methyl-H4MPT
| methyltransferase
|
|
v
Methyl-coenzyme M
|
|
| methyl-coenzyme M
| Methylreductase
|
|
v
Methane
|
|
|
|
|
|
v
to the
C1 Metabolic Cycle
Page Author(s): Jian Ma
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