01/05/2025
This blog is the sixth part of a series on innovations in the alternative protein sector. To read the previous article in the series, please see here.
With around 73 million extra people on the planet each year, and already much of the world unable to access sufficient food, it seems an impossible task to provide adequate nutrition to future generations. So, has anyone tried pulling food out of thin air?
Well, thin air is a slight exaggeration, but 95% of the reaction mixture used to make protein by air fermentation comprises molecules present in the air we breathe. Air fermentation is the process of obtaining protein from microbes cultivated with a mixture of CO2, H2, and a gaseous source of nitrogen. No other carbon source is required, and neither is sunlight, arable land, or favourable climatic conditions. This means that edible protein can be produced all year round, virtually anywhere, without the risk of weather or supply chain disruptions affecting output. Essentially, the microbes capture carbon from CO2 using energy from H2 to synthesise more microbial biomass, which is purified, dried, and processed into food.
A small number of biotech start-ups are working on this burgeoning alternative to alternative protein, and with good reason, as the air fermentation-based market is expected to be worth US $100 million by 20321.
One pioneering startup, Air Protein, claims to have crafted the world’s first air protein. The CEO, Dr. Lisa Dyson, spoke about taking inspiration from NASA research from the 1960s. In particular, NASA’s “closed loop concept”, involving recycling astronauts’ exhaled CO2 into edible carbon-based sustenance for long space flights. Their strategy was to use a chemosynthetic microbe that can convert CO2 into biomass using the chemical energy stored in hydrogen. However, the research conducted by NASA was curtailed because microbe-based cuisine was not seen as the most palatable of foodstuffs back in the 60s. However, the research unknowingly left a legacy in the alternative protein field some 60 years later.
Air fermentation technology
Chemoautotrophic bacteria (bacteria which can synthesise organic molecules from the fixation of CO2 using energy from the oxidation of an electron donor) are cultivated in a bioreactor using a feed of CO2, H2, and either NH3 or N2, depending on whether the bacteria are capable of atmospheric nitrogen fixation, to synthesise biomass using energy from oxidising hydrogen. In purely anaerobic reaction chambers, CO2 is reduced, producing cell material, H2O and acetic or butyric acid by-products. These by-products are generally undesirable as they drop the pH of the culture medium, which becomes toxic to the microbes. Thus, typically an oxyhydrogen microbe is used which can oxidise hydrogen using O2 as the oxidising agent instead of CO2. In this situation, H2O is produced as a by-product instead of acetic or butyric acid. Oxyhydrogen microbes also have a higher oxygen tolerance than strictly anaerobic microbes, which can use industrial flue gas as a source of CO2, which typically contains 2-6% O2.
The culture media also contains inorganic minerals needed by the cells to synthesis protein, such as iron, magnesium, calcium and phosphorus (comprising the remaining 5% of the reaction mixture which is not gas).
The bacterial biomass is cultivated, isolated, and dried into a powder, which is then processed to enhance safety, quality, and nutritional value. This powder can be used directly in a number of foodstuffs, such as protein-rich pasta, or it can be further processed into meat analogues using additional ingredients and flavourings. The protein-rich biomass can also be used as animal feed, including a protein substitute for fishmeal, and plant fertiliser products. With the production process for making microbial biomass in this way taking mere hours, going from “ferm to fork” takes a fraction of the time to produce the same quantity of plant or animal-derived protein.
Additionally, the protein products comprise more protein per kg than any source of meat, and is rich in vitamins and minerals, including vitamin B12, which is not found in a plant-based diet. Air fermentation proteins products are also free from hormones, antibiotics, GMOs, pesticides, and herbicides1.
The CO2 used as a carbon source can be captured through direct air capture technology, or by capturing gases from industrial processes. This captured carbon would however end up back in the atmosphere once the CO2 is breathed out after consumption of the air protein. The real climate benefits come from saving vast amounts of land used for agriculture, preventing further deforestation and allowing arable land to be turned back into carbon sinks. Renewed forests could trap carbon leading to net carbon capture and restoration of carbon sinks.
Water can also captured in the air as water vapour, and converted into H2 and O2 through electrolysis. If the electrolysis is powered by electricity from renewable sources, the production of H2 and O2 does not contribute to net carbon release.
If the bacteria can’t fix nitrogen from N2, and require the use of NH3, the synthesis of NH3 from H2 and N2 via the Haber-Bosch process requires moderately high temperatures and pressures (approximately 500°C and 20MPa) to drive the reaction forward. However, the carbon emissions required for this reaction can be offset using H2 synthesised by electrolysis ofH2O using renewable electricity. The H2 is however often derived from natural gas, coal, or oil, a process which emits CO2.
Environmental impact
Protein sources have massively diversified from a primarily livestock-based system, and the alternative protein (AP) market is growing exponentially. While plant-based alternatives occupy around 89% of the AP market, other sources have recently started to emerge. Microbe-derived proteins use almost 2000x less land per 100g protein than animal-based proteins. When compared to plant-based proteins, microbial-derived proteins consume 3-80x less land per 100g protein, depending on the type of plant and final products generated2.
We can think of the earth like a spaceship, having limited space and resources. It’s imperative that an equilibrium is reached between consumption and re-use of the earth’s resources. Animal-based agriculture accounts for around 30% of greenhouse gas emissions and 70% of the planet’s water consumption1. Agriculture, including crop production, occupies 30% of the land on earth, and causes ecological damage such as land degradation and water pollution3. On top of this, animal-based farming provides a mixing pool for zoonotic diseases, such as the emerging H5N1 avian influenza.
Air fermentation-based methods of producing protein may be the answer to providing sufficient nutritious and affordable food for a growing world population, while not contributing to net carbon release.
Innovation and Intellectual Property
Air Protein Inc. have 9 published patent families based around high-protein products of air fermentation, and their methods of production. To distinguish over competitors, Air Protein are developing meat analogues which include chicken, fish, and seafoods such as crab, lobster, shrimp and even scallops. Their first patent family that was filed (PCT/US2020/067555) has a priority date of 31 December 2019, and is directed broadly to food products and their method of production using cultured microorganisms. Since then, patent applications have been filed to structured food products, which disclose and claim various meat analogues and their methods of production, including the processing steps of converting microbial biomass into a structured food composition (WO2023278306 A1; WO2021178254 A1; WO2021195259 A1; WO2024118522 A1). Air Protein are ranked 9TH in TIME and Statista top 250 GreenTech companies of 2024, and #1 in Foodtech4. Air Protein produced first air meat, “Air Chicken”, in 2019, and created the first ever air seafood (scallop and fish) in 2021.
Netherlands-headquartered Aerbio recently acquired Deep Branch Biotechnology LTD, which has developed a single-cell protein, known as Proton, achieved through a process of gas fermentation, for the animal feed market and in particular for use in aquafeeds. The company has one published patent family, directed to methods of producing biomass using hydrogen-oxidising bacteria.
Solar Foods is another major player in the air fermentation market, having 10 published patent families directed to methods for growing microbial mass and to the products produced thereof, with priority dates dating back to 29 October 2019. Their product, Solein, is a yellowish powder composed of an unmodified, edible single-cell microbial organism with a reportedly mild aroma and notes of umami. The powder has been developed to be used as a protein alternative in many different food applications, including meat, dairy, and egg substitutes. Their first patent application families include: WO2021084159 A1; WO2022207963 A1; WO2022229504 A1; and WO2022229500 A1.
Other companies such as Arkeon GmbH and Econutri GmbH (both Austrian), Farmless (Netherlands), Avecom (Belgian) and LanzaTech (US) are also seeking to produce biomass using CO2 as a carbon source.
In terms of the regulatory status of air protein, Solein (Solar Foods) was approved for human consumption in Singapore in 2022, where so far, it has only been added to ice cream and cookies. It also obtained self-affirmed GRAS status in the US in late 2024. Its application for regulatory approval as a novel food is still pending in the UK and in the EU.5 Air Protein has also obtained self-affirmed GRAS status in the US.6
Conclusions
As climate change continues to push extreme weather events and threaten our global agriculture-dependent food system, “climate-independent” food production is getting more attention. Current barriers to APs, particularly those derived from microbes, include scale-up costs and consumer appeal. As more and more investment is put into this kind of technology, production costs will fall allowing air proteins to enter the AP market with greater momentum. Consumer demand would then be the only factor that remains to be seen.
This article is for general information only. Its content is not a statement of the law on any subject and does not constitute advice. Please contact Reddie & Grose LLP for advice before taking any action in reliance on it.
- Superfood protein pulled out of thin air massively scales up production
- An attributional life cycle assessment of microbial protein production: A case study on using hydrogen-oxidizing bacteria – ScienceDirect
- Air Protein – Making meat out of air – Food Planet Prize
- America’s Top GreenTech Companies 2024 | TIME
- Protein From Air Has A Complex Path To EU Approval
- Five To Watch in Air Protein | YFood Hub
