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Researchers from RIKEN have unveiled a newly discovered microbe that may provide insights into the origins of life on Earth, the potential for life in other parts of the universe, and methods for enhancing microbial production systems.
The study, published in Nature Communications, was conducted in the unique geological environment of northern California’s The Cedars, where a microorganism was found capable of transforming carbon dioxide into various organic compounds. This metabolism generates energy and features an intriguing, previously uncharacterized metabolic pathway, hinting at ancient principles of energy conversion that may have been present in primitive life forms on Earth.
Lead researcher Shino Suzuki, a microbiologist at the RIKEN Cluster for Pioneering Research in Wako, Japan, noted the uniqueness of these findings. The extreme conditions that these microorganisms endure could represent a model for early Earth environments thought to spur life’s beginnings. The newly identified carbon fixation process could offer methods to enhance microbial production of chemicals and biofuels.
Investigation into Origins of Life
The microorganism studied is a single-celled archaeon from The Cedars, located roughly 150 kilometers from San Francisco. This area features extraordinary mineral formations resulting from reactions between subterranean rocks and water.
The environment is rich in calcium, hydrogen, and methane gas, while lacking elements typically essential for supporting life. Remarkably, life exists and flourishes in this seemingly inhospitable setting.
Suzuki and her team began evaluating microbes in this extreme environment around 15 years ago, employing cutting-edge genetic sequencing techniques to classify various bacteria and archaea. This ongoing research has revealed a wide variety of unique microbes, each displaying distinct genomic characteristics and metabolic roles.
Among these, the archaeon named Met12 stands out. Found thriving in The Cedars’ deep groundwater, genetic analysis indicated a close relation to a category of anaerobic microbes renowned for methane generation. However, Met12 lacks the necessary genes for methane production. Instead, it employs an alternative metabolic process that converts carbon dioxide into acetate, an organic compound, without releasing methane. A distinctive gene called MmcX plays a crucial role in enhancing this process.
Through her research, Suzuki has demonstrated that MmcX increases the electron-uptake efficiency of Met12, facilitating its energy-generating metabolism in the extreme conditions prevalent at The Cedars. This discovery illustrates how life can adapt and thrive in unexpected ways within harsh environments, which could mirror the beginnings of life on early Earth or potential life forms elsewhere in the universe.
Initially skeptical of their results, Suzuki and her international team had to rely on reconstructing the microbe’s circular genome using gene sequences, as traditional culturing methods proved ineffective. They used synthetic biology techniques to validate their findings by introducing the MmcX gene into a genetically modified bacterium, which enabled a better understanding of Met12’s metabolic processes.
Practical Applications of Discovery
The implications of these findings extend beyond theoretical understanding. By enhancing the metabolic capabilities of bacteria typically used in biofuel production, they can potentially improve efficiency in manufacturing chemicals and biofuels. This advancement has prompted the researchers to file a patent on the innovative technology utilizing MmcX.
The characterization of this archaeon also presents opportunities for advancements in carbon sequestration, a vital strategy for combating climate change and reducing greenhouse gas emissions.
Looking forward, Suzuki envisions further groundbreaking discoveries as her research team continues to explore The Cedars and other extreme environments that may harbor untapped genetic diversity. Current explorations include locations such as Japan’s Hakuba Happo hot springs and the profound underwater volcanoes of the Mariana Trench.
“There are many fascinating genes yet to be discovered,” she stated, illustrating the vast potential that remains in studying extremophiles and their unique characteristics.
More information: Shino Suzuki et al, A non-methanogenic archaeon within the order Methanocellales, Nature Communications (2024). DOI: 10.1038/s41467-024-48185-5
Citation: Microbe opens the door to carbon dioxide–driven manufacturing (2024, October 17) retrieved 17 October 2024 from https://phys.org/news/2024-10-microbe-door-carbon-dioxidedriven.html
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