India’s first cultures of indigenous natural methane mitigating agents reported from rice fields and wetlands, mainly from Western India can help tackle upcoming climate challenges.
Scientists at Agharkar Research Institute (ARI), Pune, an autonomous institute under the Department of Science & Technology, have isolated 45 different strains of methanotrophic bacteria which have been found to be capable of reducing methane emissions from rice plants.
What are Methanotrophs and what is their significance in environment?
Methanotrophs metabolize and convert methane into carbon-di-oxide. They can effectively reduce the emission of methane, which is the second most important greenhouse gas (GHG) and 26 times more potent as compared to carbon-di-oxide. Methanotrophs are natural methane mitigating agents and are present in all the environments where methane and oxygen both are available. Wetlands, rice fields, ponds and other water bodies are the habitats where these grow in abundance.
These micro-organisms help in mitigating the ill effects of global warming caused due to methane gas.
Dr. Monali Rahalkar, a scientist from MACS Agharkar Research Institute, an autonomous institute of Department Science and Technology, with her team, have isolated and described India’s first cultures of indigenous methanotrophs from rice fields and wetlands, mainly from Western India. Isolating methanotrophs from India, they published the first novel methanotroph description from India, a novel genus and species -- Methylocucumis oryzae.
Methylocucumis oryzae were found to be important methanotroph components of a stone quarry in Pune, situated amidst the popular hill, Vetal Tekdi or ARAI hill. This hill has its own unique flora and fauna including the stone quarry water having unique invertebrates and mollusks.
Dr. Rahalkar’s team also recently documented the abundance of methanotrophs in the water filled quarry, which indicated that an active methane cycle operated in this unique habitat.
After about 6 years of description and around 10 years of isolation of its first member, Methylocucumis oryzae remain phylogenetically unique. No strains have been reported or cultured from any other country or parts of the world. It has a remarkably large size compared to other bacteria and is equal to the size of a small yeast (3-6 µm).
Another unique feature of this bacterium is that it has a strict mesophilic nature and cannot grow above 37ºC while most of the other methanotrophs can tolerate or grow at 37ºC or even at 40ºC.
In recent years, this methanotroph was also found to promote the growth of rice plants by inducing early flowering and increased grain yield.
There is evidence that this organism exists in nature in abundance in wetlands and rice fields and may be performing its function in a meticulous manner.
Rahalkar, Monali C., Jyoti A. Mohite, Kajal Pardhi, Shubha S. Manvi, Yash S. Kadam, and Yukta V. Patil. “Insights into Methylocucumis oryzae, a Large-sized, Phylogenetically Unique Type Ia Methanotroph with Biotechnological Potential.” Indian Journal of Microbiology, July 5, 2024. https://doi.org/10.1007/s12088-024-01347-x.
(Input from various sources)
(Rehash/Tushar Pandey/MSM)