Sunlight enters the system and living cells emerge.
In a London laboratory, scientists have built a device that mirrors one of nature's oldest achievements — transforming sunlight, water, and carbon dioxide into living matter — without a single leaf involved. Researchers at Queen Mary University combined solar electrochemistry, enzymes, and genetically engineered bacteria into one integrated glass reactor, demonstrating that the boundary between chemistry and biology can be dissolved in service of a cleaner industrial future. The work is early, but it points toward a world where factories draw their raw materials not from underground reserves, but from the air above us.
- For decades, solar chemistry and microbial engineering have advanced in parallel but separate tracks — this device forces them to coexist in a single vessel, a convergence that has long resisted practical realization.
- The central tension was toxicity: earlier solar-powered systems released metal ions that killed the bacteria, making true integration impossible until a new organic solar component sidestepped the problem entirely.
- Researchers spent 168 days evolving their E. coli strains under formate-fed stress until a mutation emerged that allowed the bacteria to grow in days rather than weeks, turning a bottleneck into a breakthrough.
- Under simulated sunlight, the reactor converted CO2 into formate at 98% efficiency, and isotope-labeling confirmed the carbon in the resulting biomass genuinely came from the air — not a workaround, but the real thing.
- The system remains a proof of concept measured in hours and micromoles, but its modular design means different bacteria, enzymes, or solar materials can be swapped in, opening a platform rather than just a single experiment.
In a laboratory at Queen Mary University of London, researchers have built a device that does what plants have done for hundreds of millions of years — converting sunlight, water, and carbon dioxide into living matter — but without a leaf in sight. The reactor, described in the Journal of the American Chemical Society, integrates solar panels, enzymes, and genetically engineered bacteria into a single glass vessel, solving a problem that has long frustrated scientists: how to make solar chemistry and living biology work together in the same space.
The device operates through a chain of linked reactions. One electrode splits water to release oxygen; a second, enzyme-equipped electrode captures dissolved CO2 and converts it into formate, a simple one-carbon molecule. Engineered E. coli bacteria then consume the formate, using the device's own oxygen output to grow. In ten hours of operation, the system produced formate at nearly 98% efficiency — and photons entering the system yielded living cells as the output.
Formate was chosen deliberately. Unlike sugars, it can be made directly from CO2 using renewable energy, requiring no crops or farmland. But early bacterial strains grew too slowly on it. The team ran 168 days of adaptive laboratory evolution, repeatedly culturing bacteria under formate-fed conditions until faster-growing cells dominated — cutting growth time from nearly two weeks to just two days, likely through a mutation in a phosphate transporter gene.
The decisive test was replacing external electrical power with an organic solar cell. Earlier solar-driven attempts had poisoned bacteria with toxic metal ions; the new component generated sufficient voltage while avoiding that problem entirely. To confirm the carbon truly came from the atmosphere, researchers repeated the experiment using carbon-13-labeled CO2 — the isotope appeared in the resulting formate, verifying that atmospheric carbon had genuinely become living matter.
The complete system, which the team calls a semiartificial leaf, remains an early proof of concept — yields are modest and operation is measured in hours. But Dr. Lin Su, who led the work, emphasized that the architecture is now proven: different bacterial strains could be plugged into the same hardware to manufacture different molecules. If scaled, the platform could someday produce plastics, chemicals, fuels, or food proteins from captured atmospheric carbon — replacing fossil fuel extraction with a process powered by sunlight and air.
In a laboratory at Queen Mary University of London, researchers have built something that does what plants have been doing quietly for hundreds of millions of years—turning sunlight, water and carbon dioxide into living matter. The difference is that this machine does it without a leaf in sight, using instead a carefully orchestrated dance of solar panels, enzymes and genetically engineered bacteria all contained within a single glass device.
The reactor, described in the Journal of the American Chemical Society, represents a significant convergence of two scientific approaches that have long remained separate. One uses sunlight to drive chemical reactions that transform carbon dioxide into useful molecules. The other uses engineered microbes programmed to manufacture valuable products. Until now, combining them in a single functioning system has proven elusive. Earlier attempts required separate reactors or complex transfer steps between chemical and biological components—extra steps that increased costs, reduced efficiency and made scaling difficult. The new design solves this by creating what researchers call a "one-pot" integrated reactor, where solar-powered chemistry and living bacteria coexist in the same liquid environment.
Here's how it works: sunlight powers a series of linked reactions inside the device. One electrode splits water molecules, releasing oxygen that the bacteria need to survive. A second electrode, equipped with an enzyme, captures dissolved carbon dioxide and converts it into formate—a simple one-carbon molecule that acts as an energy carrier. The engineered E. coli bacteria then consume this formate, using the oxygen produced by the device itself to extract energy and build new biomass. In essence, photons enter the system and living cells emerge. During 10 hours of operation, the setup produced about 650 micromoles of formate per square centimeter, with nearly all supplied electrons going toward formate production, yielding an efficiency rate close to 98 percent.
The choice of formate and E. coli was deliberate. Formate can be made directly from carbon dioxide using renewable energy, unlike sugars which require crops and farmland. This opens the possibility of what researchers call a "formate bioeconomy," where atmospheric carbon becomes the starting material for manufacturing instead of fossil fuels. E. coli was chosen because scientists already understand its genetics and metabolism in detail, and over recent years have engineered strains capable of using formate as an energy source. But those strains initially grew slowly. The team spent 168 days conducting adaptive laboratory evolution, repeatedly culturing the bacteria under formate-fed conditions until faster-growing cells dominated. The results were striking: the evolved strain reached similar growth levels in just two days instead of nearly two weeks, likely due to a mutation affecting a phosphate transporter gene that helped the bacteria conserve energy under stressful alkaline conditions.
The real test came when researchers replaced the external electrical power supply with an organic solar cell. This was crucial because earlier attempts to power such systems with solar energy had run into a persistent problem: the chemistry typically released toxic metal ions that poisoned the bacteria. The new solar component generated enough voltage to drive carbon dioxide reduction while avoiding this toxicity. Under simulated sunlight, the reactor generated substantial amounts of formate, which the evolved bacteria then consumed and converted into biomass. The team verified that the carbon truly came from the air by repeating the experiment with carbon dioxide labeled with carbon-13 isotopes—the resulting formate contained the isotope, confirming the system had actually converted atmospheric carbon into living matter.
The complete integrated system, which researchers describe as a semiartificial leaf, combined an organic semiconductor photocathode with a bismuth vanadate photoanode on a small glass platform. When operated for 20 hours under light exposure, it generated both formate and oxygen while supporting bacterial survival. Initially, bacterial biomass dropped slightly because oxygen production remained limited, but once researchers added trace minerals and adjusted the surrounding gas atmosphere, growth resumed. In dark control experiments, biomass steadily declined, confirming that light was powering the entire process.
This remains an early-stage proof of concept. Yields are still relatively small, and the system currently operates for hours rather than weeks. Yet researchers believe they have demonstrated something fundamental: that a fully integrated solar-biological reactor is scientifically possible. Dr. Lin Su, who led the work, noted that once the integration works, different engineered bacterial strains could be plugged into the same hardware to produce different molecules. The implications are substantial. If efficiency can be improved and production scaled, engineered microbes could someday manufacture plastics, specialty chemicals, fuels or food proteins using captured carbon dioxide. Instead of extracting carbon from underground oil and gas reserves, future factories might recycle atmospheric carbon into useful materials. The platform is modular, meaning researchers can potentially swap different enzymes, solar materials or bacterial strains into the same framework. Challenges remain before commercialization becomes realistic—scientists still need to improve long-term stability, oxygen management and productivity. But the study shows that the basic architecture is sound, marking an important step toward cleaner industrial systems powered by sunlight and air.
Citas Notables
For a clean chemical industry to replace the fossil-fuel one, the chemistry that captures CO2 and the biology that turns it into useful products will eventually need to share the same device.— The research team
Once that integration works, a synthetic biologist can plug a different engineered E. coli strain into the same hardware to produce a different molecule.— Dr. Lin Su, Queen Mary University of London
La Conversación del Hearth Otra perspectiva de la historia
Why does it matter that they did this all in one container instead of separate reactors?
Because every transfer step between systems costs you. You lose material, you lose efficiency, you introduce complexity. If you're trying to build something that could actually replace fossil fuel manufacturing, you need it to be simple enough and efficient enough to scale. One container means one process, one set of conditions to optimize.
The bacteria grew seven times faster after 168 days of evolution. What was actually happening in those cultures?
They were selecting for survival. Every generation, the bacteria that could extract energy from formate most efficiently got to reproduce more. Over time, a mutation emerged in a gene that helps them manage phosphate—essentially, they learned to waste less energy on housekeeping under difficult conditions. It's evolution in fast-forward, but it's still just natural selection at work.
Why formate specifically? Why not just make sugar?
Sugar requires farmland, crops, the whole agricultural apparatus. Formate you can make directly from CO2 and electricity. If you're trying to build a manufacturing system that doesn't depend on fossil fuels, you need a feedstock that comes from air and sunlight, not soil. That's the whole point.
The 98 percent efficiency number—is that actually good?
For converting CO2 into a useful chemical using electricity, yes, that's genuinely impressive. It means almost every electron they're putting in is doing the job they want. The real challenge now is doing it at scale and keeping it stable for weeks instead of hours.
What happens if this actually works at industrial scale?
You'd have factories that pull carbon out of the air, use sunlight to convert it into building blocks, and grow bacteria that turn those blocks into whatever you need—plastic, protein, chemicals. No oil wells. No coal mines. Just air, water, and light. That's the dream they're chasing.