In the scope of my dissertation, I am focusing on methane and nitrogen cycling that is both abiotically and microbially driven. Tropical peatlands constitute overlooked potential sources and sinks of atmospheric methane and nitrous oxide. My research questions include (I) how abiotic and biotic reactions during nitrification/denitrification are modulated to cause nitrous oxide production, (II) what the geochemical and microbial drivers of these reactions are and (III) how methane and nitrogen cycling is coupled. My work also comprises environmental monitoring at selected sites in the Amazon as well as efforts to isolate and culture novel anaerobic microorganisms in the lab. For NExSS, it is important to distinguish between biotic and abiotic processes and to identify potential biosignatures. My work elucidates this potential for key gases in the nitrogen cycle, such as nitric or nitrous oxide.