Photons enter. Living biomass exits.
In a single glass vessel at Queen Mary University of London, researchers have achieved something quietly historic: sunlight, water, and carbon dioxide entering one end, and living bacterial biomass emerging from the other — no plant required. By marrying organic solar cells with engineered E. coli bacteria through a carefully chosen chain of enzymes and energy carriers, Dr. Lin Su's team has dissolved a long-standing incompatibility between solar chemistry and synthetic biology. The work does not yet replace industrial chemistry, but it establishes, for the first time, that the two great clean-manufacturing traditions of our era can share the same home.
- The chemical industry's dependence on fossil fuels has long made the dream of a solar-powered, biology-driven alternative feel perpetually out of reach.
- Every previous attempt to combine light-harvesting materials with living bacteria in one reactor failed — the chemistry that captured CO₂ produced metal ions that poisoned the microbes.
- The breakthrough came through careful component selection: an organic solar absorber, a purified enzyme, formate as a safe energy carrier, and a bacterial strain that could coexist with all of them.
- Inside the reactor, three reactions now run in sequence from a single light source — water splitting, CO₂ reduction, and bacterial growth — closing the loop from photon to living biomass.
- Yields are still small and the reactor runs for hours, not weeks, but the principle is proven and the modular design means different bacterial strains can be swapped in to produce pharmaceuticals, food proteins, or polymers.
- Scientists see this as the foundational demonstration of an 'integrated solar refinery' — a future device that could manufacture chemicals, materials, and food from sunlight, water, and air alone.
Inside a single glass vessel, sunlight is now powering something unprecedented: a complete chain of reactions that turns carbon dioxide and water into living bacteria, all at once, in one place. Researchers at Queen Mary University of London, led by Dr. Lin Su, have built an integrated solar reactor combining an organic solar cell, two enzymes, a semiconductor electrode, and genetically engineered E. coli into a system that mimics photosynthesis — without any naturally photosynthetic organism involved. The work appears in the Journal of the American Chemical Society.
The chemical industry today runs almost entirely on fossil fuels, and two cleaner alternatives have been developing in parallel: solar-powered chemistry that converts CO₂ into useful molecules, and engineered bacteria that can manufacture a wide range of products. Earlier attempts to combine them in a single reactor always failed for the same reason — the chemistry that captures CO₂ typically produces toxic metal ions that poison the bacteria. The two systems could not coexist.
This reactor solves that problem through its choice of components. An organic light absorber, a purified enzyme as catalyst, formate as the energy carrier, and a carefully selected E. coli strain all proved mutually compatible. Crucially, each element can be independently swapped out — the solar cell redesigned, the enzyme re-engineered, the bacterial strain rewired for a different target chemical. The reactor is a platform, not a fixed machine.
The reactions unfold in sequence from a single light source: sunlight splits water on one electrode, releasing oxygen the bacteria need; a second electrode uses an enzyme to convert dissolved CO₂ into formate, which carries captured solar energy in a form the bacteria can metabolize; the bacteria then consume the formate and use the oxygen to grow, drawing in still more CO₂. Photons enter. Living biomass exits.
The current version is early-stage — yields are small, and the reactor runs for hours rather than weeks. But the principle is proven. Once integration works, a synthetic biologist can introduce a different engineered strain into the same hardware to produce pharmaceuticals, polymers, or food proteins. Professor Ron Milo of the Weizmann Institute noted that growing bacteria from CO₂ could eventually supply food using far less land and water. The technology is not yet ready to replace industrial chemistry, but for the first time, the path from this laboratory beaker to that future looks clear.
Inside a single glass vessel, sunlight is doing something that has never been done before: powering a complete chain of reactions that turns carbon dioxide and water into living bacteria, all in one place, all at once. Researchers at Queen Mary University of London, led by Dr. Lin Su, have built an integrated solar reactor that combines an organic solar cell, two enzymes, a semiconductor electrode, and genetically engineered E. coli bacteria into a system that mimics photosynthesis without needing a plant, an alga, or any naturally photosynthetic organism to do it. The work, published in the Journal of the American Chemical Society, represents a fundamental shift in how scientists think about making chemicals and materials sustainably.
The chemical industry today runs almost entirely on fossil fuels. Two competing visions for a cleaner future have been developing in parallel: solar-powered chemistry, which uses sunlight to convert CO₂ into useful molecules, and engineered bacteria, which can be programmed to manufacture a wide range of products. Until now, these two approaches have been kept separate. Earlier attempts at hybrid systems—devices that tried to house both a light-absorbing material and microbes in the same reactor—have foundered on a persistent problem: the chemistry that captures CO₂ typically produces toxic metal ions that poison the bacteria. The two systems poisoned each other. They could not coexist.
What makes this new reactor different is its architecture and its choice of components. The team selected an organic light absorber, a purified enzyme as the catalyst for CO₂ reduction, formate as the energy carrier, and an engineered E. coli strain as the biological engine. Each of these pieces can be independently modified or swapped out. The solar cell can be redesigned. The enzyme can be re-engineered. The bacterial strain can be rewired to produce a different target chemical. This modularity is not incidental—it is the entire point. The reactor is designed to be a platform, not a fixed machine locked into one chemistry.
Inside the beaker, three reactions unfold in sequence, all powered by the same light. Sunlight splits water on one electrode, releasing oxygen that the bacteria need to breathe. On a second electrode, an enzyme captures CO₂ dissolved in the liquid and converts it into formate, a small molecule that carries the energy from the captured photons in a form the bacteria can metabolize. The bacteria then consume the formate, using the oxygen the device has just produced to burn it for energy. That energy allows them to build themselves—to grow—using more CO₂ dissolved in the same liquid. Photons enter. Living biomass exits.
Dr. Su explained the significance of this integration: the chemistry and the biology can now share a single container, using sunlight, water, and CO₂ to grow living biomass without toxic interference. Once that integration works, a synthetic biologist can introduce a different engineered E. coli strain into the same hardware to produce a different molecule entirely. The system becomes a platform for manufacturing, not a one-off experiment.
The current version is early-stage. Yields are small. The reactor runs for hours rather than weeks. But the principle has been proven: the full chain from photons to bacterial biomass in a single liquid is possible. This opens a path toward engineered strains that produce target chemicals beyond simple biomass—pharmaceuticals, polymers, food proteins, materials that today require petroleum to manufacture.
The implications ripple outward. For a clean chemical industry to replace the fossil-fuel one, the chemistry that captures CO₂ and the biology that converts it into products will eventually need to share the same device. Two-step processes with manual transfer between reactors are too expensive and inefficient to scale. This work is an early demonstration that compatibility is achievable inside one beaker, laying the foundation for what researchers call an integrated solar refinery—a single system that could produce chemicals, materials, and microbial protein from sunlight, water, and air. Professor Ron Milo of the Weizmann Institute noted that successful integration of these systems will be key to sustainable production, and that advances in growing bacteria from CO₂ could supply food using far less land and water, potentially addressing both climate and ecological challenges at scale. The technology is not yet ready to replace industrial chemistry. But for the first time, the path from laboratory to that future looks clear.
Notable Quotes
Previously, the problem with trying to make living biomass in a solar-powered chemical reactor is that the chemistry typically releases toxic metal ions that poison the bacteria. We have shown that a solar-powered chemical reactor and engineered bacteria can share a single beaker, using sunlight, water and CO₂ to grow living biomass safely.— Dr. Lin Su, Queen Mary University of London
The successful integration of these two systems is going to be key to sustainable production technologies. Advancements in growing bacteria using CO₂ open the way for supplying our food in a way that uses much less land and water and can scale to meaningfully dampen the climate and ecological challenges humanity faces.— Professor Ron Milo, Weizmann Institute of Science
The Hearth Conversation Another angle on the story
Why does it matter that the chemistry and biology happen in the same beaker instead of two separate ones?
Because moving material between reactors is expensive and loses energy. If you want to scale this to actually replace fossil-fuel chemistry, you need everything integrated. One beaker, one process, no transfer losses.
But the source says yields are still small and it only runs for hours. How is that promising?
The promise isn't in the current performance—it's in the proof that it's possible at all. They've solved the poisoning problem that killed every previous attempt. Now they can tune each component independently. Better enzymes, better solar cells, better bacterial strains. Each one improves the whole system.
What would it actually make? Is this just for chemicals, or could it be food?
Both. The reactor grows bacterial biomass—living cells. You could harvest that as protein for food. Or you could engineer the bacteria to produce specific chemicals: plastics, pharmaceuticals, materials. The same hardware, different bacterial strain.
So it's modular.
Exactly. That's the real innovation. Earlier hybrid systems were locked into one chemistry. This one is designed to be swapped and modified. It's a platform, not a machine.
How long until this actually works at industrial scale?
They don't know. Yields are small, runtime is hours not weeks. But they've removed the fundamental barrier—the toxicity that made integration impossible. Everything else is engineering.
And if it does scale?
Then you could grow food or manufacture chemicals using sunlight, water, and CO₂, using far less land and water than traditional agriculture or petrochemistry. That's the scale of what's at stake.