The project Methanotrophs from natural ecosystems as biocontrol agents for ruminant methane emissions investigated methanotrophs and their potential to reduce methane emissions from extensive livestock in Australia.
Summary
In ruminant cattle, the anaerobic fermentation of ingested plant biomass results in the production of methane (CH4). The CH4 is subsequently eructated to the environment, where it acts as a potent greenhouse gas and is one of the leading sources of anthropogenic CH4 in Australia.
Methane oxidising microorganisms are an important environmental sink for CH4; however the possibility that methanotrophs are native to the rumen has received little attention.
The Methanotrophs from natural ecosystems as biocontrol agents for ruminant methane emissions project aimed to characterise methanotrophs from a range of environments, and to subsequently determine the metabolic activity of these microorganisms under in vitro rumen-like conditions. This study is the first to characterise rumen methanotrophs using molecular methodology.
Using a combination of denaturing gradient gel electrophoresis and phyloGenetics and genomics, it was found that simple communities of Proteobacterial methanotrophs can be native residents of the rumen microbial community in grain-fed Bos indicus steers. A putative methanotrophic Gamma-proteobacterial Methylobacter species was also enriched from grain-fed whole rumen contents using novel techniques.
However, the activity of these organisms in situ remains to be fully understood. Furthermore, the possibility that a grain-based dietary affect influences the diversity and activity of methanotrophs in situ is intriguing. Future work to address these questions is necessary to evaluate the potential for methanotrophs to act as biocontrol agents for ruminant CH4 emissions.
Project concluded: 1 December 2011
Contact: Dr Diane Ouwerkerk
Collaborator: Department of Agriculture and Fisheries, University of Queensland
More information
For more information, please read the final report summary and download the final report (B.CCH.1013) from the Meat & Livestock Australia website.
