Scientists from New Zealand are part of an international research collaboration which has made an important discovery in the quest to lower global agricultural methane emissions.
The University of Otago scientists are all members of the Global Research Alliance on Agricultural Greenhouse Gases that has identified new processes that control methane production in the stomach of sheep and similar animals like cattle and deer.
Specifically, they determined the microbes and enzymes that control the supply of hydrogen, the main energy source for methane producing microbes (methanogens).
The discovery —published in The International Society for Microbial Ecology Journal—is important because methane emissions from animals account for about a third of New Zealand’s emissions.
“Much of our work to date has focused on the development of small molecule inhibitors and vaccines to specifically target the production of methane by methanogens,” Professor Greg Cook said.
“This new work provides an alternative strategy where we can now begin to target the supply of hydrogen to methanogens as a new way of reducing animal methane emissions.”
The researchers studied two types of sheep—those producing high amounts of methane and those producing less. They found the most active hydrogen-consuming microbes differed between the sheep. Importantly, in the low methane emitting sheep hydrogen consuming bacteria dominated, which did not produce methane.
Their findings lay the foundation for strategies to reduce methane emissions by controlling hydrogen supply. One strategy is to introduce feed supplements that encourage non-methane producers to outcompete methanogens.