Lac Pavin Permanently Stratified Lake Community

A depth-stratified microbial community in Lac Pavin, a deep, permanently stratified lake in central France. Genome-resolved analyses across the oxygen gradient reveal enrichment of distinct C1 and CO2 fixation pathways in the oxic lake interface and the anoxic zone and sediments, with oxygen shaping non-CPR bacterial and archaeal metabolic strategies. RuBisCO genes are detected throughout the water column and sediments, including form II/III and form III-related enzymes encoded by Candidate Phyla Radiation (CPR) bacteria in the water column and DPANN archaea in the sediments. Methane oxidation and its byproducts are largely spatially separated from methane production, which is mediated by diverse sediment methanogens that vary on the centimeter scale.