Using formic acid, a new technique converts carbon dioxide into a useful resource for the biochemical sector.

In addition to assisting in the reduction of atmospheric carbon dioxide, new synthetic metabolic pathways for the fixation of carbon dioxide have the potential to substitute biological, carbon-neutral manufacturing processes for pharmaceuticals and active ingredients. Formic acid can be used to transform carbon dioxide into a valuable material for the biochemical industry, according to a new study that was published in Nature Communications.

Carbon capture, or the sequestration of carbon dioxide from large emission sources, is an urgent issue in light of rising greenhouse gas emissions. In nature, carbon dioxide digestion has been occurring for a long period of time; however, its ability is a long way from adequate to repay man-made outflows.

Nature’s arsenal is being utilized by the Max Planck Institute for Terrestrial Microbiology’s Tobias Erb-led team to develop novel strategies for carbon dioxide fixation. They have now prevailed with regards to fostering a counterfeit metabolic pathway that creates the profoundly responsive formaldehyde from formic corrosive, a potential middle-of-the-road result of fake photosynthesis. Without producing any toxic effects, formaldehyde could be directly fed into several metabolic pathways to produce additional valuable substances. Similar to the natural process, there are two essential components: carbon and energy. The first can come from electricity, such as from solar modules, as well as direct sunlight.

Formic corrosive is a C1 building block.
Inside the additional value chain, the carbon source is variable. All monocarbons (C1 building blocks) are in question, including carbon dioxide, which is not the only option in this case: formaldehyde, methanol, carbon monoxide, formic acid, and methane. Notwithstanding, practically, these substances are exceptionally harmful — either to living organic entities (carbon monoxide, formaldehyde, and methanol) or to the planet (methane as an ozone-depleting substance). Many microorganisms can only tolerate formic acid when it is neutralized to its base form in high concentrations.

“Formic corrosive is an exceptionally encouraging carbon source,” says Maren Nattermann, the first creator of the review. ” However, the test tube conversion to formaldehyde requires a lot of energy. ” This is due to the difficulty of converting formate, a salt of formic acid, into formaldehyde. There’s a serious synthetic obstruction between the two particles that we need to connect with biochemical energy — ATP — before we can play out the genuine response.”

The researcher wanted to find a cheaper method. After all, the more energy that remains to drive growth or production, the less energy is required to feed carbon into metabolism. However, there is no such path in nature. It takes innovativeness to find purported unbridled compounds with numerous capabilities,” says Tobias Erb. ” However, candidate enzymes’ discovery is only the beginning. We’re discussing responses that you can count alongside since they’re so sluggish— at times, short of one response per second for every chemical. Normal responses can happen multiple times quicker.”

Maren Nattermann says that this is where synthetic biochemistry comes in. You can intervene wherever an enzyme’s structure and mechanism are known. We greatly benefit from the preliminary work of our basic research colleagues in this area.”

The enzymes were optimized using a variety of strategies, including high-throughput technology: building blocks were exchanged specifically, and random mutations were created and chosen for their capability. Due to their ability to penetrate cell walls, formate and formaldehyde are excellent partners. According to Maren Nattermann, “we can put formate into the culture medium of cells that produce our enzymes and convert the formaldehyde produced into a non-toxic yellow dye after a few hours.”

The outcome could never have been conceivable in a brief time frame without the utilization of high-throughput strategies. The researchers collaborated with their German industrial partner, Festo, to accomplish this. “We achieved a fourfold improvement in production after approximately 4,000 variants,” says Maren Nattermann. We have consequently made the reason for the model mikrobe Escherichia coli, the microbial workhorse of biotechnology, to develop on formic corrosive. However, for the time being, our cells can only produce formaldehyde and cannot further convert it.”

The researchers are currently working on developing a strain with collaborator Sebastian Wenk at the Max Planck Institute for Molecular Plant Physiology to be able to absorb the intermediates and introduce them into the central metabolism. In parallel, the team collaborates with a Walter Leitner-led working group at the Max Planck Institute for Chemical Energy Conversion to investigate the electrochemical transformation of carbon dioxide into formic acid. An “all-in-one platform”—from carbon dioxide through an electrobiochemical process to products like insulin or biodiesel—is the long-term objective.

More information: Maren Nattermann et al, Engineering a new-to-nature cascade for phosphate-dependent formate to formaldehyde conversion in vitro and in vivo, Nature Communications (2023). DOI: 10.1038/s41467-023-38072-w

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