5 min read
Highlights
CO₂ to protein could become a new pillar of food security, as long as the energy equation works:
- Carbon becomes a feedstock: Microbes can convert CO₂, hydrogen and oxygen into nutrient-rich biomass without livestock or land-intensive agriculture.
- The process is two-stage: One microbe produces acetate and folic acid, while baker’s yeast converts the acetate into protein-rich, folate-enriched biomass.
- The economic model: A modelled 1,750 m³ facility could pay back in roughly five years under the specified assumptions.
- The opportunity sits at a powerful intersection: Alternative proteins and synthetic biology could combine to collectively reshape food production.
- Energy remains the gatekeeper: Electricity and hydrogen produced through electrolysis are the major cost drivers.
CO₂ to protein is moving from an intriguing scientific concept towards a serious food-system conversation on the future of food.
Researchers led by Lars Angenent at the University of Tübingen have developed and modelled a two-stage microbial process that turns simple chemical inputs into protein and vitamin B9, also known as folic acid.
The idea is wonderfully simple, even if the biology is not.
Carbon becomes dinner. But only when the energy equation works.
A food factory built from biology
The CO₂ to protein process is called power-to-protein when the emphasis is on protein production and power-to-vitamin when the focus is on folate.
It bypasses the traditional requirement for fields, feedlots and livestock. Instead, it uses CO₂, water-derived hydrogen and oxygen as inputs for controlled microbial conversion.
This isn’t simply eating carbon. Carbon dioxide isn’t a food ingredient that can be sprinkled into a recipe. It must first pass through a carefully managed biological pathway where microbes transform inorganic carbon into molecules that living cells can use.
The system has two stages.
- Stage one uses the bacterium Thermoanaerobacter kivui in an oxygen-free environment. With hydrogen as an energy source, it reduces CO₂ to acetate. It also produces folic acid, or vitamin B9.
- Stage two introduces baker’s yeast, Saccharomyces cerevisiae, along with the acetate and oxygen. The yeast uses the acetate to grow, producing a protein-rich, folate-enriched biomass.
That sequence is the key. One organism creates the intermediary feedstock and the vitamin. Another turns that feedstock into something nutritionally useful.
It’s less like growing a crop and more like operating a biological assembly line.
The scale is promising, but modelled is the important word
The underlying peer-reviewed PNAS study evaluates the integrated CO₂ to protein system at industrial scale from a techno-economic perspective. The Phys.org report has brought the findings into the wider food and climate conversation.
The headline numbers are significant.
A modelled facility with a volume of 1,750 m³ could produce approximately 12.9 kilotonnes of yeast annually. That biomass would contain about 813 kilograms of folic acid and 5.6 kilotonnes of protein.
According to the model, this would be enough to provide the recommended daily folic-acid dose to around 5.6 million people and contribute 5% of their protein needs.
At a modelled price of USD 20 per kilogram of enriched yeast, the facility could pay back its investment in roughly five years. Under ideal assumptions, including no cost associated with producing CO₂ and higher yeast productivity, the price could fall to USD 4.53 per kilogram.
That best-case figure assumes the CO₂ feedstock is effectively free, rather than something that must be purchased, captured, purified or transported specifically for the process.
A purified full-protein pathway would be more complex. It could require around USD 14.24 per kilogram and a seven-year payback at USD 20 per kilogram.
The study identified no technical blockers to scaling in its calculations. However, industrial demonstration, purification, regulation, safety, sensory performance and consumer acceptance still need to be addressed.
The yeast can be safe as a small dietary supplement for vitamin B9. If it’s intended to meet a person’s full protein requirements, purification is needed to remove compounds that may trigger gout. That adds complexity and cost.
Two technologies converge in one vessel
This microbial food factory sits at the intersection of two important technology fields.
That’s especially interesting because microbial biomass sits directly between alternative proteins and synthetic biology. It’s a food ingredient, but it’s also the output of a programmable biological system.
That combination could prove extremely valuable.
The real factory is an energy system
The biggest cost drivers identified in the CO₂ to protein study are electricity and hydrogen production through electrolysis.
This is the critical point. The future of power-to-food won’t be determined by biology alone. It will be shaped by the cost, reliability and carbon intensity of energy.
If hydrogen is expensive or produced with high-emissions electricity, the business case weakens. If clean electricity becomes abundant and affordable, entirely new production models become possible.
That’s why I keep returning to the relationship between energy and food. My earlier article on The Fourth Engine explores how energy can act as an accelerator across the food system. The logic applies here, too, especially for CO₂ to protein.
It also connects with decentralised production ideas such as on-farm fertiliser production. In both cases, energy becomes a route to greater resilience and reduced dependence on long, fragile supply chains.
Designing food for 11 billion entities
By 2050, the food system will need to support 11 billion entities. That includes 9.7 billion humans and 1.3 billion pet cats and dogs.
That broader metric matters because future food demand won’t be defined by human mouths alone. It will include companion animals, changing diets, nutritional deficiencies, climate pressures and the need to produce more with fewer resources.
No single microbial factory will solve that challenge. Nor will alternative proteins, precision fermentation or renewable energy in isolation.
The opportunity lies in combining them.
I believe power-to-protein is an important signal of what a resilient food system could look like. Energy provides the input. Biology performs the conversion. Engineering creates the scale. Regulation and consumers determine whether the result earns a place in the market.
The food factory of the future may not have fields outside its walls. It may have bioreactors, electrolyser stacks and a constant requirement for clean, affordable power.
Carbon dioxide + hydrogen + biology + clean energy = a new pathway to food resilience.
To continue the conversation email me at tony@tonyhunterspeaker.com