India Discovers Natural Allies To Defeat Methane

The first cultures of indigenous methane-mitigating agents, discovered in rice fields and wetlands primarily in Western India, offer a potent solution to climate challenges. Methane, a potent greenhouse gas with 26 times the global warming potential of carbon dioxide, is naturally counteracted by methanotrophs—methane-eating bacteria. These bacteria oxidise methane, producing CO₂ and H₂O, thereby preventing methane levels from skyrocketing.

Dr. Monali Rahalkar and her team at MACS Agharkar Research Institute, under the Department of Science and Technology, have isolated and described the first indigenous methanotroph cultures in India. Among them, Methylocucumis oryzae, a novel genus and species, stands out. Named for its cucumber-like shape, this bacterium was found in rice fields and wetlands, contributing significantly to methane mitigation.

The research team also discovered these methanotrophs in a unique habitat—a stone quarry at Vetal Tekdi Hill in Pune. This site, with its unique flora and fauna, further demonstrates the bacteria’s versatility. Over the years, Methylocucumis oryzae has remained phylogenetically unique, with no strains reported or cultured elsewhere.

Methylocucumis oryzae promotes rice plant growth, inducing early flowering and increasing grain yield, as shown in pot experiments with the high-yielding Indrayani rice variety.

Although slow growth limits large-scale cultivation for broader biotechnological applications, the bacterium’s abundance in nature ensures its crucial role in methane mitigation.

Insights on Methylocucumis oryzae were recently published in the Indian Journal of Microbiology. This discovery is vital for further studies and applications in addressing climate challenges, highlighting the importance of improving culture conditions for large-scale use.