Peatland Bacteria Feeds on Greenhouse Gas

Researchers from the Radboud University Nijmegen have discovered that new bacteria found in the soil beneath a peatland reserve in the Netherlands actually consume methane.

In Limburg, the Netherlands, new bacteria living in the soil beneath the Brunssummerheide peatland reserve have been found to be methane-consuming, a harmful greenhouse gas. Gijs van Dijk, an aquatic ecologist who made the bacteria discovery, took several soil samples and found that methane was found deep in the peat section of the soil, but found no trace of methane at the soil surface. That discovery caused the research to want to find out how that methane was disappearing.

Katharina Ettwig, microbiologist at Radboud University Nijmegen, found the answer. Ettwig had already known that certain bacteria van oxidize methane anaerobically by using nitrogen compounds such as nitrates and nitrites. After extensive research at the peatland reserve, it was discovered that a new type of bacteria was living in the soil and had capabilities of making pure oxygen from nitrites, which allows the bacteria to burn methane and provide the bacteria with its own source of energy.

Every anaerobic peat soil contains methane, but the groundwater in the peatland reserve contains unusually high levels of nitrates, due to leaching from woodland and agricultural soils. This combination of methane, nitrate, and the presence of oxygen in the peat provides ideal conditions for the Methylomirabilis bacteria. The bacteria are therefore already found in methane and nitrate-rich soils: Natuurmonumenten will therefore mainly use this information to monitor groundwater pollution and tackle it at the source.

The researchers are investigating whether the global increase in nitrogen pollution is reducing methane emissions in other ecosystems and looking into the cell biology and biochemistry of the bacteria to find out if it has any practical applications, such as in water treatment. The Nijmegen Institute for Water and Wetland Research (IWWR) research group has a great deal of experience in cultivating, studying and finding applications for slow-growing, anaerobic bacteria.