"What we have found is an extremely tough methane-consuming organism that is new to science. It grows happily under extremely acidic conditions in the lab."
Another GNS microbiologist, Peter Dunfield, who isolated the bacterium, has tentatively named it Methylokorus infernorum, which is a latinised description of its methane food source, the 'hellish' location of its discovery and also a description of a structure within its cell that resembles a koru.
Methanotrophs live mostly in soils and are especially common in environments where methane is produced.
Globally, acidic environments such as marshes and peat bogs generate significant quantities of methane.
Scientists have always suspected that a proportion of this methane was being consumed by bacteria living in these environments.
Dr Stott said the bacterium was found about 30cm down from the surface, where manuka and scrub had died through steam incursion at the Tikitere geothermal field, also known as Hell's Gate.
It was cultured in the lab, and found to be able to tolerate environments that were at least mildly acidic.
"The discovery of this micro-organism is fairly important scientifically - previously microbiologists had only known that methane was consumed by micro-organisms in very mildly acidic environment.
"We knew it probably occurred at lower pHs but no one was ever able to grow them or detect them."
Initial calculations estimate that a cubic metre of liquid containing the micro-organism is able to consume up to 11kg of methane a year.
"We now know that bacteria can grow in these areas so it helps us track down these acidic micro-organisms a little bit better," Dr Stott said.
"It's a first step of a large area of research which we hope to start looking into.
"Ultimately, it may be possible to implant this organism, or a similar one, in landfills and cut methane emissions into the atmosphere."
The discovery has just been published in a paper in the science journal Nature. It stemmed from a collaboration between GNS and the owner of Hell's Gate, the Tikitere Trust.
Methane muncher
* A bacterium that feeds on methane has been found at Hell's Gate near Rotorua.
* Scientists estimate a cubic metre of liquid containing it can consume up to 11kg of methane a year.
* They hope the bacterium can be implanted in landfills to cut emissions of methane gas which increase global warming.
