Microorganisms discovered at a depth of 1,250 meters under the Earth’s surface had the ability to convert carbon dioxide into crystalline structures

Located in the subterranean depths of South Dakota’s Black Hills, there exists a bacteria with the capacity to efficiently convert carbon dioxide (CO2) into a solid mineral under very challenging circumstances. If scientists can harness these peculiar bacteria, they might provide a novel method for capturing greenhouse gases from exhausted fossil fuel sources.

A team of scientists from Soeder Geoscience LLC and the South Dakota School of Mines and Technology recently conducted a search for microorganisms capable of sequestering carbon under the extreme temperatures and pressures present in an oilfield.

They successfully identified three very potential prospects. A type of Bacillus bacterium was found at a depth of 1,250 meters (4,100 feet) at the Sanford Underground Research Facility, the deepest underground laboratory in the United States, situated in the South Dakota Black Hills.

The last two species consisted of a Geobacillus species, known for its ability to thrive in extreme heat and pressure conditions, and Persephonella marina, a “hyperthermophile” discovered in the hydrothermal vents of the Pacific Ocean, capable of withstanding temperatures as high as 110°C (230°F), high saline levels in seawater, and elevated pressure.

The bacteria underwent a series of laboratory studies that exposed them to various intense pressures, temperatures, and acidities.

Their first findings indicated that the most favorable circumstances for the microorganisms to generate calcite crystals from CO2 were at a pressure 500 times higher than that of sea level, at a temperature of 80°C (178°F). Given the very challenging circumstances, the bacteria were able to efficiently transform CO2 into carbonate crystals in a little span of 10 days.

The bacteria accomplish this task by the activity of an enzyme known as carbonic anhydrase, which facilitates the interaction between CO2 and water.

The vacant cavities resulting from exhausted oil and gas reservoirs provide an optimal site for the storage of collected CO2, thereby preventing its release into the Earth’s atmosphere, where it functions as a greenhouse gas and contributes to climate change.

Given the bacteria’s ability to thrive in the challenging environments of exhausted oil and gas fields, there is potential to introduce them into subterranean cavities and permanently sequester CO2.

Moreover, the solid carbonates may serve as an efficient barrier that prevents the escape of leftover liquids and gas from the decommissioned oil wells.

Although still speculative, the progress made in carbon capture technologies, like the one mentioned, has the potential to be an indispensable asset in addressing the climate emergency.

Undoubtedly, the potential for carbon capture should not diminish the immediate need to decrease the combustion of fossil fuels; it is futile to clean up the floor while the bathtub is still overflowing.

The study was shown at the American Geophysical Union meeting in San Francisco in the latter part of the previous year.