Methane Cycling Microbial Communities in Natural and Drained Sites of Taldom Peatland, Moscow Region, Russia

Abstract

Aims: Drainage of peatlands is known to decrease overall CH4 emission, but the effect on methane cycling microbes is poorly described. For this reason we aimed to reveal the differences in methanogenic and methanotrophic communities between pristine peatlands and its counterpart that was drained in 1979. Study Design: Comparative molecular analysis of microbial communities involved in methane cycling. Place and Duration of Study: Peat samples were collected in July 2012 in Taldom natural and drained sites of Dubnensky peatland massif. Methodology: Total DNA was extracted from fresh peat samples and analyzed by PCR-DGGE technique in order to evaluate diversify of key functional genes for methanotrophy (pmoA) and methanogenesis (mcrA) as well as the phylogenetic archeal16S rRNA genes. FISH method was applied to count Bacteria and Archea. Results: Our results demonstrated that in natural peatlands hydrogenotrophic methanogens dominated, but in the drained peats both hydrogenotrophic and acetothrophic methanogens were found. It was revealed striking difference between methanotrophs of natural and drained peatlands. Sequence analysis of marker pmoA gene, suggested that Methylocystis –like methanotrophic Alphaproteobacteria were dominants in natural peatlands. Conversely Methylobacter was found to be actively involved in CH4 oxidation in the drained peats. Conclusion: This study indicates drastic changes in structure of CH4-cycling microbial communities, affected by drainage and can be applied as environmental indicators in monitoring of anthropogenic influence on peatland ecosystems.