Metabolic Process of Strange Bacteria Can be Used to Converting Carbon Dioxide Into Solar Fuels

In order to artificially photosynthesize carbon dioxide into solar fuels, researchers have demonstrated a new method that is based on a metabolic process present in some bacteria.

Scientists search carbon-hungry microbes in fight against climate change

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The ability of some bacteria to consume electrons and CO2 to generate acetate, a reaction powered by the electrons, has long been known to scientists, as per ScienceDaily.

A carbonyl group (CO) or a methyl group are the two distinct or asymmetric chemical groups that result from the pathway's breakdown of CO2 molecules (CH3).

The carbons in CO and CH3 can bond or couple thanks to enzymes in this reaction pathway, which then starts a second catalytic process that results in the ultimate product, acetate.

It has been difficult to find synthetic electrocatalysts that function as effectively as the naturally occurring enzymatic catalysts found in bacteria.

This has prevented researchers in the field of artificial photosynthesis from creating devices that mimic the chemistry of the pathway known as asymmetric carbon-carbon coupling.

Read More: Laboratory-Made CO2-Eating Bacteria Could Help Solve Climate Change, Says Scientists

Enhancing artificial photosynthesis using copper likes carbon

The ability of copper to transform carbon into a variety of beneficial chemicals was initially identified in the 1970s. These earlier investigations led Yang and his team to conclude that copper-catalyzed artificial photosynthesis devices should be capable of converting CO2 and water into methyl and carbonyl groups, which can subsequently be transformed into acetate.

According to the researchers' theory, CO would adhere to the surface of copper, causing the asymmetric coupling of CO and CH3 groups to generate acetate. In the tests, isotope-labeled CH3I was employed to monitor the reaction route and byproducts.

Yang's lab at UC Berkeley conducted chemical analysis studies that showed that copper's coupling of carbonyl and methyl groups created not just acetate but also other useful liquids like acetone and ethanol.

The researchers were able to determine that the acetate was produced by the reaction of CO and CH3 thanks to the isotopic tracking.

A solution of copper and silver nanoparticles, each measuring 7 nanometers in diameter, was used by the researchers to create an ultrathin material in a different experiment.

The copper nanoparticles changed CO2 into a methyl group, while the silver nanoparticles changed CO2 into a carbonyl group as a result of the electrical bias.

The researchers discovered that the copper and silver nanoparticles formed tandem systems and were in intimate touch with one another using electron microscope tests at the Molecular Foundry. The copper nanoparticles also functioned as the catalytic core for asymmetric coupling.

Bacteria known for eating CO2

The bacterium Clostridium autoethanogenum was created by scientists at the synthetic biology firm LanzaTech in Illinois to ferment carbon monoxide and carbon dioxide into common chemicals like acetone and isopropanol, which are the building blocks for acrylic glass and polypropylene plastics as well as for cleaning products and rubbing alcohols, as per Inverse.

This method uses carbon dioxide and other gases to produce a beneficial byproduct that makes it carbon-negative, which means that it can reduce the quantity of carbon dioxide released into the atmosphere, which causes heat and, consequently, climate change.

These chemicals, which can assist in removing carbon dioxide from the environment, can now be produced in a cleaner manner thanks to research.

By eating sugar during fermentation, yeast creates ethanol. The bacterium has already been modified to consume CO and CO2 and create these compounds in this analogous method.

It produces ethanol in its pre-engineered, natural state. The bacterium now can make acetone or IPA thanks to synthetic biology.

Related Article: Scientists Engineered Special Bacteria That Turns Carbon Dioxide to Valuable Chemicals