Microbial Interactions in Methane & Sulfate Cycling

In this research project, we are investigating how the ongoing decline in sulfur deposition is affecting methane cycling in lakes. Across Sweden, sulfate concentrations in surface waters have been decreasing—an environmental shift that may have unforeseen consequences for microbial communities and the biogeochemical processes they drive.

Our focus is on understanding how reduced sulfate availability influences key microbial processes such as methanogenesis (methane production) and methane oxidation. One aspect we are particularly interested in is the competitive relationship between methanogens and sulfate-reducing bacteria, as changes in sulfate levels can shift the balance between these groups and alter the rate of methane production.

These microbial pathways play a central role in regulating the flux of methane, a potent greenhouse gas, from aquatic ecosystems to the atmosphere. By examining the links between sulfur dynamics and methane cycling, we aim to better understand how freshwater ecosystems respond to changing chemical inputs and what this means for their contribution to climate-relevant gas emissions.