Permafrost environments in the Arctic are characterised by extreme environmental conditions which demand a specific resistance from microorganisms to survive under these conditions. For the understanding of the carbon dynamics in the climate sensitive arctic permafrost environments the activity and diversity of methanogenic communities was studied in three different permafrost soils of the Siberian Laptev Sea coast. The effect of temperature and availability of methanogenic substrates on the CH4 production was analysed. Furthermore, the diversity of methanogens was analysed by PCR with specific methanogenic primers and DGGE followed by sequencing of DGGE bands re-amplified from the gel. Our results demonstrated methanogenesis in each investigated permafrost soil with a distinct vertical profile. The soils on Samoylov Island showed at least two optima of CH4 production activity, which indicated a shift in the methanogenic community from mesophilic to psychrotolerant methanogens with increasing soil depth. Furthermore, it was shown that CH4 production in permafrost soils is substrate limited although these soils are characterised by the accumulation of organic matter. Sequence analyses revealed a distinct diversity of methanogenic archaea affiliated to Methanomicrobiaceae, Methanosarcinaceae and Methanosaetaceae. However, a relationship between the activity and diversity of methanogens in permafrost soils could not be shown.
Helmholtz Research Programs > MARCOPOLI (2004-2008) > POL7-From permafrost to deep sea in the Arctic