Hendrik Schaefer

We study microorganisms that cycle trace gases and degrade pollutants. Despite their small size, microorganism have a major role in nature as recyclers of organic matter. Their activity has a decisive impact on how organic and inorganic compounds are distributed in terrestrial and marine environments. They also degrade a wide range of environmental pollutants. Microorganisms produce and consume volatile compounds and trace gases which affect air quality and the composition of the Earth's atmosphere. Despite their low concentrations, trace gases have wide ranging consequences for climate and human health. For instance, microorganisms produce the sulfur gas dimethylsulfide (DMS) which gets emitted into the atmosphere where it leads to formation of aerosols which have a cooling effect. In anoxic environments, DMS can be an important precursor for the greenhouse gas methane. Methane is degraded by methanotrophic bacteria in a wide range of environments, their activities are an important control for methane emissions to the atmosphere. We are also interested in characterising microorganisms degrading carbon monoxide, a toxic gas that impacts human health as well as being an indirect climate warming gas. Overall, our work is aiming to increase our understanding of microbial trace gas and pollutant cycling using a range of methodologies, including microbiological and molecular biological approaches. Current work addresses cycling of organic sulfur compounds such as DMS, carbon monoxide and methane by marine, terrestrial and plant-associated microorganisms from the temperate zones to the high Arctic.