Why in news?
A new species of methane‑eating bacteria, Methylocucumis oryzae, has been isolated from Asian rice paddies. Researchers believe that harnessing such microbes could help reduce greenhouse gas emissions from agriculture.
Background
Methanotrophic bacteria consume methane as their energy source. They play a key role in mitigating methane emissions from wetlands, rice paddies and landfills. Rice cultivation is a major source of anthropogenic methane, as waterlogged soils promote anaerobic decomposition that releases the gas.
Characteristics of Methylocucumis oryzae
- Discovery: Scientists isolated this bacterium from the rhizosphere (root zone) of rice plants in temperate Asia. The name comes from the Latin words for “cucumber” and “rice,” reflecting the cell’s shape and habitat.
- Metabolism: The microbe oxidises methane into carbon dioxide and water, using a specialised enzyme called methane mono‑oxygenase. It can grow under low oxygen conditions typical of flooded fields.
- Association with rice: Researchers found that the bacterium forms a mutually beneficial relationship with rice plants. It inhabits root surfaces and supplies extra carbon dioxide that plants can use for photosynthesis.
Potential applications
- Greenhouse gas reduction: Enhancing populations of methanotrophs like Methylocucumis oryzae in rice paddies could lower methane emissions, contributing to climate change mitigation.
- Biofertilisation: By converting methane to carbon dioxide, these bacteria may improve plant growth in nutrient‑poor soils.
- Biotechnology: Methanotrophs produce valuable bioproducts, such as single‑cell proteins and biodegradable plastics, which can be harnessed industrially.
Conclusion
The discovery of Methylocucumis oryzae underscores the hidden biodiversity within agricultural soils. Promoting beneficial microbes could transform rice cultivation from a methane source into a more climate‑friendly system.
Source: Nature Microbiology