Gas-munching microbe may reduce emissions

January 31st, 2013 BY Hilary Feldman | No Comments

A new species of bacteria has been discovered in a geothermally active part of New Zealand. What makes this microbe special is its resilience – along with its ability to consume methane.

Methanotrophic bacteria feed on methane, converting it to carbon dioxide as a digestive product. While carbon dioxide is a contributor to global warming, methane is a far more potent gas, able to trap 20 times more heat in the atmosphere. Typically, it is produced by the breakdown of organic material. There are many natural and anthropogenic sources of methane; human activities are thought to contribute about 60% of global methane emissions.

The new bacterium, tentatively named Methylokorus infernorum and a member of the Verrucomicrobia Family, survives an extreme environment in an area known as Hell’s Gate, near Rotorua. It can withstand very acidic conditions. Other bacteria in this group inhabit geothermal springs, marshes and peat bogs, degrading the methane naturally found in such acidic sites.

Wetlands are a major source of methane, along with volcanic regions. However, the methane formed in natural systems is partly recycled through the action of indigenous methanotrophic bacteria. Most human-produced methane has no such scheme in place, even for biological production of methane through rice farming. Methane is also a major component of natural gas.

Atmospheric methane is removed through processes known as “sinks”. Chemical reaction with hydroxyl radicals (OH) is an important sink, resulting in a methyl group (CH3) and water. Soil microbes use methane, providing another sink, while methane reacts with chlorine in seawater for a third sink. As human activities cause increased methane emissions, existing sinks cannot keep pace.

The potential application of this bacterial discovery is emission reduction. Methane gas is produced from geothermal power plants, mines, landfills, industrial waste, and other sources. Methanotrophic bacteria may be used for bioremediation of contaminated soil and groundwater; they are able to break down chlorinated solvents such as trichloroethylene, used in industry and dry-cleaning. The many possible uses for this newly described methanotroph emphasize the importance of basic research to understand different ecosystems and maintaining biodiversity.

  1. What do you have to say?