Oxidation of atmospheric methane in forest soils

Methane is one of the most important greenhouse gases, and the most abundant organic compound in the atmosphere (ca 2 ppmv). 90% of the annual contribution is oxidised by OH-radicals in the stratosphere, but a large part is also oxidised by microorganisms in different biotopes, most commonly in dry forest soils in temperate areas.
The hypothesis for this project is that methane oxidation in temperate forest soils is maintained by other carbon compounds, that make methanotrophs competitive, since one form of the methane-oxidising enzyme, sMMO (soluble methane monooxygenase) can oxidise a broad spectrum of organic compounds except methane, which also includes aromatic compounds. Interesting examples in this context are different derivatives of lignin and pectin, where it is known that oxidases similar to sMMO are active.

Soil samples are taken from a nearby forest, where we earlier have found strong consumption of atmospheric methane. Experiments will be done with incubated soil samples, followed by chemical and microbiological analyses.

Keywords: microbiology, climate change, greenhouse gases
Sökord: mikrobiologi, metan, klimat, växthusgaser, skogsjord