Development of high-throughput analytical methods (DNA chip) for studying the ecology of microbial methane oxidation

Methanotrophs are bacteria capable of utilising methane as their sole source for carbon and energy. Methane is oxidised in four steps via methanol, formaldehyde and formate to carbon dioxide, or is incorporated into cell biomass at the oxidation level of formaldehyde. Methanotrophs represent the largest biological sink for methane, the second most important greenhouse gas after carbon dioxide. Methane oxidation in anaerobic environments is believed to be carried out by a consortium of methanogens and sulphate reducers. Methane is 26-30 times more effecitve in adsorbing and reflecting long-wawe radiation, than carbon dioxide, thus the oxidation of methane to carbon dioxide decreases the greenhose effect. Landfill sites produce about 10% of the methane entering the atmosphere. Soils above landfill sites were shown to contain methanotroph populations with the highest methane oxidation capacity measured. The potential of methanotrophs in reducing the amount of methane reaching the atmosphere and thus decreasing the greenhouse effect warrants detailed studies on their diversity and ecology. Such studies have been perfomed in large numbers in the past but their integration has been hampered by the lack of a high-throughput, standardisable method. As a consequence there is still very limited information available on the ecoogical niches inhabited by the different species and genera of methanotrophs. Such information is the prerequisite of planning new environmental policies in order to minimise the amount of methane released into the atmosphere. The expertise of the research group will be unified in the proposed 3 year project in order to develop a DNA chip for the rapid, detailed, reproducible investigation of methanotroph ecology, including aerobic and anaerobic methane consumption. The developed chip will first be tested on soil samples from different landfill site mimicking experiments, and data on their diversity will be linked to physico-chemical and methane oxidation capacity data of the samples they originate from. These combined data will for the first time enable the assigment of ecological niches to methanotroph species as well as confirm or contradict the current theory of anaerobic methane oxidation. The results will also be utilisied in designing new practices for landfill site managing companies in order to minimise methane emissions. The developed DNA chip will also be used in revisiting environmental samples previously characterised with respect to methanotroph diversity thus generating comparable results and enabling the refinement of the niche assignment.