An international team of scientists has discovered a new way to store carbon dioxide at high speeds in a bacterial enzyme that could ultimately help fight climate change.
The accumulation of carbon dioxide in the atmosphere has led to a steady worsening of the climate crisis, which in turn has prompted scientists to intensify their search for solutions on how to store it. The study was published in the London-based weekly scientific journal Nature on the 20th of July.
According to the research team, an enzyme that occurs in heat-loving bacteria is named Thermoanaerobacter kivui could lead to new ways to dump excess carbon dioxide.
The bacterium, which lives in low-oxygen environments like the deep sea, was first discovered in 1981 in Lake Kivu in central Africa.
The team led by Dr. Ben Engel at the Biozentrum of the University of Basel in Switzerland together with colleagues from the Universities of Frankfurt and Marburg in Germany highlighted that the enzyme known as HDCR produces formic acid from gaseous hydrogen and carbon dioxide.
Also, it then extracts carbon dioxide from the environment and stores it in the cell while transferring electrons from hydrogen to carbon dioxide.
This, as the Swiss university notes, is the first known enzyme that can use hydrogen directly as an electron source to store carbon dioxide.
After elucidating the HDCR structure, the researchers reported that the enzyme consists of long filaments that act as electron-conducting ‘nanowires’, controlling the conversion efficiency of the two gases.
One of the first authors of the study, Dr. Ricardo Righetto from the Biozentrum at the University of Basel added: “It is the structure of the enzyme that enables rapid CO2 storage.”
To understand how the enzyme works, the scientists first imaged laboratory-cleaned filaments, which helped them determine its atomic structure.
The university added: “This revealed details of the filaments and showed how the ‘nanowire’ contains thousands of electron-conducting clusters of iron and sulfur atoms, allowing electrons to be efficiently transferred from hydrogen to carbon dioxide.”
“The scientists believe that the ‘nanowire’ can store the electrons from hydrogen even if just one hydrogen bubble passes the bacteria.”
After tomography of frozen cell sections to image native HDCR structures in the bacterial cells, the filaments began to twist around themselves several times like a metal cable.
Righetto said: “We were really surprised not only to confirm the presence of HDCR filaments in the cells, but also to find that they form large bundles that attach to the membrane.
“These superstructures look like circular “portals” on the membrane. This arrangement could be important to increase the efficiency of the enzyme for the bacteria to harvest energy under such extreme conditions.”
Engel added: “The HDCR structure shows us a new way to efficiently store CO2 by using hydrogen as an energy carrier.
“This could prove very useful for future biotechnological applications.
“At the same time, our study shows the value of basic scientific research that investigates the biology of different organisms.
“Nature is full of amazing surprises.”
This story was provided to Newsweek by Zenger News.
https://www.newsweek.com/carbon-dioxide-storing-bacteria-enzyme-help-fight-climate-change-1727987 Carbon dioxide sequestering bacterial enzyme may help fight climate change