SRA

Peatlands represent a valuable ecological asset and contribute to climate regulation of the Earth. On only 3% of the terrestrial surface, up to 600 Gt of C is stored in peat across the globe, which represent about 25% of the global soil C stock. This is due to the current environmental conditions of the peatlands, which favour plant production over degradation by micro-organisms. Northern hemisphere peatlands store higher amount of carbon (C) in bogs than in fens, but microbial determinants in driving C dynamics remains poorly explored. Here we took advantages of a fen-to-bog gradient to investigate the role of bacteria, archaea and virus in organic matter degradation by genome-centric approach. Identifying the key actors of OM decomposition and the factors controlling their activities, might help to 1. better understand C storage process 2. predict the consequences of climate change on C storage in peatlands, which still under debate today. We characterized this gradient through the sampling of 3 sites, at different depths (i.e. -7.5, -42.5 et -92.5 cm), during a rainy and cold spring and a hot and dry summer (from May to November 2018). Different microforms (i.e. hummock and hollow) were sampled at each site, for a total of 24 metagenomes. We identified the key actors in OM decomposition by reconstructing and examining the metabolic capacity of 290 unique bacterial and archaeal metagenome-assembled genomes (MAGs).