Long term this could help the dairy industry in, say, the production of protein feeds. And because it shows the methane-oxidising bacteria working elsewhere, there are implications for cutting greenhouse gas emissions.
Soil bacteria that oxidise methane (methanotrophs) capture methane before it enters the atmosphere, and scientists now know they can consume hydrogen gas to enhance their growth and survival.
This new research is published in the International Society for Microbial Ecology Journal.
Industrial companies are using methanotrophs to convert methane gas emissions into useful products, for example liquid fuels and protein feeds.
“The findings of this research explain why methanotrophs are abundant in soil ecosystems,” says Dr Chris Greening from the Centre for Geometric Biology at Monash University.
“Methane is a challenging energy source to assimilate. By being able to use hydrogen as well, methanotrophs can grow better in a range of conditions.”
Methanotrophs can survive in environments when methane or oxygen are no longer available.
“It was their very existence in such environments that led us to investigate the possibilities that these organisms might also use other energy-yielding strategies,” Greening says.
The research was co-led by Dr Carlo Carere and Dr Matthew Stott from GNS Science, New Zealand.
Carere, a geothermal microbiologist team leader of the Geomicrobiology Research Group at GNS, told Dairy News this work shows that methane-consuming bacteria are better able to survive in environments when using both methane and hydrogen gases – as opposed to methane alone.
“We showed this effect was particularly significant in soils where oxygen was limiting and suggested this increased metabolic flexibility may allow these bacteria to colonise a greater diversity of (soil) environments than previously believed.
“This may have implications for the conversion of methane emissions into valuable fuel of feed chemicals.
“For the pastoral industry, it is possible the modelling of methane gas emissions should be modified to include the usage of both methane and hydrogen gas.”
Greening and collaborators found and studied a methanotroph from a NZ volcanic field. The strain could grow on methane or hydrogen separately, but performed best when both gases were available.
“This study is significant because it shows that key consumers of methane emissions are also able to grow on inorganic compounds such as hydrogen,” Greening says.
“This new knowledge helps us to reduce emissions of greenhouse gases.”
