Exploiting rumen genome sequencing to reduce methane emissions
This post is the last in a series of blogs written by the authors of papers which were presented at the recent Greenhouse Gases & Animal Agriculture Conference held in Dublin. All papers are published in the journal animal.
Domestic livestock such as cattle, sheep and goats produce large amounts of methane as part of their normal digestive process. In fact, globally, the agriculture sector is considered the primary source of anthropogenic methane emissions.
Development of mitigation strategies to reduce methane emissions from farmed animals is currently the subject of both scientific and environmental interest. Contrary to popular belief it is not the animal itself that is responsible for the methane but actually a group of microbes known as methanogens that live within the animal.
Livestock are home to an enormous number and diversity of microbes. These microbes allow the animal to digest the plants that make up their diet but some of the end-products of this digestive process are used by methanogens to produce methane. Therefore, any methane mitigation strategy developed by researchers will at some stage impact upon methanogens. You can achieve an impact by either targeting the methanogens themselves or targeting the other rumen microbes that produce substrates necessary for methane production.
Genome sequencing is an important tool to gain knowledge both of the methanogens, and of the processes that underpin the interactions between methanogens and other rumen microbes. The ability to sequence a genome provides access to all of the biological information needed for growth and maintenance of a living organism.
In New Zealand, researchers affiliated to the New Zealand Agricultural Greenhouse Gas Research Centre and the Pastoral Greenhouse Gas Research Consortium are investigating the genome sequences of rumen methanogens to figure out ways to selectively knock them out without damaging the other, beneficial microbes. Possible approaches include vaccines, small molecule inhibitors, animal breeding or even changing forage.
Additionally, worldwide, scientists from the rumen microbiology community have come together through the auspices of the Global Research Alliance on Agricultural Greenhouse Gases and with the support of the New Zealand government and the US Department of Energy, Joint Genome Institute community sequencing programme to launch the Hungate1000 project (http://www.hungate1000.org.nz/). This project aims to generate a catalogue of reference genomes from rumen microbes with a view to understanding digestive function and enabling a balance to be found between food production and greenhouse gas emissions.
Genome sequencing of rumen bacteria and archaea and its application to methane mitigation strategies
LeahySC, Kelly WJ, Ronimus RS, Wedlock N, Altermann E and Attwood GT