) is an important intermediate in the global carbon cycle. Per year about 1 Gt methane is formed from biomass and further oxidized to CO2
. The formation of methane involves mainly anaerobic microorganisms, whereas in the oxidation of methane both anaerobic and aerobic microorganisms participate. In the atmosphere, where methane acts as a greenhouse gas, methane is predominantly re-mineralized photochemically. Investigations of the biochemistry of the methane cycle have led over and over again to new discoveries. On two of the most recent discoveries will be reported here.