| Genus |
Cell
shape
and
Arrangement |
Motility |
Cell
size |
Optimum
Growth
Temperture |
Major
Energy
Yielding
Process |
| Methanobacterium |
Rods
or
chain
forming
coccoids |
Non
motile
or
motile
by
polar
flagella |
0.5
-
1.00µm |
37-75 |
Reduction
of
CO2 to
methane
with
H2 |
| Methanosarcina |
Large
cocci
in
packets |
Non
motile |
1.5-2.5µm |
30-37 |
Formation
of
methane
from
acetate |
| Methanococcus |
cocci
occuring
singly,
in
pairs
or
clumps |
Motile
or
Non
motile |
0.5-4.0µm |
30-40 |
Formation
of
methane
from
H2 +
CO2 formate,
acetate
or
butyrate |
