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Updated: Jul 2, 2026
11:02
The Use of an Automated System (GreenFeed) to Monitor Enteric Methane and Carbon Dioxide Emissions from Ruminant Animals
Published on: September 7, 2015
Methane oxidation and its coupled electron-sink reactions in ruminal fluid
H Kajikawa1, C Valdes, K Hillman
1National Institute of Livestock and Grassland Science, Tsukuba Norindanchi, Ibaraki, Japan.
Letters in Applied Microbiology
|May 20, 2003
Summary
Methane oxidation occurs in sheep rumen, though at low levels. This anaerobic process involves reverse methanogenesis and sulfate reduction, with methane oxidation suppressed by oxygen.
Area of Science:
- Microbiology
- Environmental Science
- Animal Science
Background:
- Ruminant digestion produces significant methane, a potent greenhouse gas.
- Understanding methane metabolism in the rumen is crucial for mitigating emissions.
Purpose of the Study:
- To investigate the occurrence of methane oxidation in the rumen.
- To identify the specific electron-sink reaction coupled with methane oxidation.
Main Methods:
- Incubation of mixed ruminal microbes from sheep with 13CH4.
- Quantification of 13C flux to CO2 and microbial biomass.
- Assessment of inhibitors (oxygen, 2-bromoethanesulfonate, molybdate, tungstate) on methane oxidation.
Main Results:
- Methane oxidation was detected, accounting for 0.2-0.5% of total methane production.
- Oxygen presence suppressed methane oxidation.
- 2-bromoethanesulfonate and molybdate inhibited methane oxidation, while tungstate did not.
Conclusions:
- Anaerobic methane oxidation occurs in the rumen.
- This process is linked to reverse methanogenesis and sulfate reduction.
- Methane oxidation is sensitive to specific inhibitors, providing insights into its biochemical pathways.
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