Across industries, vast amounts of valuable byproducts are discarded daily, despite their potential to become high-value resources. Biotechnology is revolutionizing this paradigm by converting waste gases like methane into nutritious protein for feed and food applications. As the biotech industry advances, integrating sustainable resource utilization will be critical for long-term success of building more resilient food systems.
New Product Development, Sustainability, & Regulatory Affairs Director
Unibio
Global demand for protein continues to rise, driven by population growth, rising incomes, and shifting diets. At the same time, conventional protein production, whether from livestock, soy cultivation, or fishmeal production, places significant pressure on ecosystems.
Livestock farming accounts for about 14.5% of global greenhouse gas emissions (FAO, 2013). Most emissions come from methane (CH₄) and nitrous oxide (N₂O), released through enteric fermentation, manure management, and fertilizer use for feed crops (IPCC, 2021). Soy expansion is a leading cause of deforestation in South America (WWF, 2021), while fishmeal production threatens marine ecosystems and food security for communities that rely on fish as a staple (FAO, 2020). Meanwhile, the use of land, water, and fertilizers in conventional protein production is already unsustainable in many regions, and climate change is making these challenges worse (World Bank, 2019).
In short, the world faces a protein paradox: We need to produce more, but we must do it with far fewer resources. This challenge has sparked growing interest in alternative proteins, from plant-based and cultivated meat to microbial proteins and algae. These innovations offer an opportunity to rethink the role of protein in food systems not only as a dietary requirement, but also as a driver of sustainability, resilience, and circular economy models.
SUPPORTING SUSTAINABLE GROWTH IN GLOBAL FOOD SYSTEMS
Unlike traditional linear models of “take-make-dispose”, the circular bioeconomy aims to keep resources in use as long as possible, minimize waste, and regenerate natural systems through the “reduce-reuse-recycle” model (OECD, 2018). In food systems, this means finding ways to use byproducts, side streams, and even waste gases as valuable inputs for new production.
Alternative proteins are particularly well suited to this approach, as their production relies on non-traditional inputs, which allows companies to transform low-value resources into high-quality protein. This creates multiple benefits:
• Waste reduction: By using byproducts like methane, agricultural residues, or industrial CO₂, alternative proteins prevent pollution while generating value.
• Resource efficiency: Many microbial and fermentation-based proteins require little to no land and far less water than conventional protein sources (FAO, 2021).
• Climate impact: By decoupling protein production from deforestation, overfishing, and intensive farming, alternative proteins reduce greenhouse gas emissions and preserve biodiversity (IPCC, 2021).
• Resilient growth: New protein sources diversify supply chains, reducing reliance on fragile global commodity markets (World Economic Forum, 2019).
In this way, alternative proteins support a resilient, circular bioeconomy where secure, diversified protein supplies meet growing demand with lower environmental impact. Several companies are already putting these principles into practice, demonstrating how alternative proteins can transform waste into high-value resources.
FROM METHANE TO PROTEIN TO FEED
A leader in this field is Unibio, a Danish biotechnology company with a pioneering method for converting methane into protein. The company’s flagship product, Uniprotein®, is a single-cell protein produced through a proprietary Vertical Loop fermentation process, in which naturally occurring microbes are cultivated using methane as a carbon and energy source. Methane is a potent greenhouse gas, released from agriculture, landfills, and industrial processes, often wasted or flared, with a warming potential more than 25 times that of carbon dioxide over a century (IPCC, 2021). By capturing methane and turning it into protein for feed, Unibio provides a double benefit: Reducing emissions and producing a high-quality, safe, and scalable protein ingredient for animal feed.
Source: Unibio
This innovation is particularly important in the context of animal farming, which consumes vast quantities of protein in the form of feed, particularly soybean meal and fishmeal. These conventional feed ingredients are resource-intensive, contribute to deforestation, and create volatility in global feed markets. By converting industrial byproducts and side streams into alternative proteins, feed producers can reduce reliance on imported soy and wild-caught fish, while simultaneously improving feed security for farmers (FAO, 2020).
Looking at the bigger picture, this shows how biotechnology can turn waste into value and build more resilient food systems by applying circular economy principles. Methane-to-protein approaches provide a clear example of how innovation, sustainability, and efficient resource utilization can come together to strengthen food security.
KALUNDBORG SYMBIOSIS: A LIVING EXAMPLE OF CIRCULARITY
Unibio’s approach to protein production is further strengthened by its participation in Kalundborg Symbiosis, an industrial cluster located in the city of Kalundborg, Denmark, which is recognized worldwide as a model of circular economy in action. Kalundborg Symbiosis operates on a simple but powerful principle: One company’s byproduct can become another’s resource. Since its establishment in the 1970s, the symbiosis has expanded into a network of more than a dozen companies that exchange energy, water, and materials to reduce costs, cut emissions, and generate new value (Kalundborg Symbiosis, 2022) (Figure 1).
Source: Kalundborg Symbiosis
The impact is significant. Each year, the symbiosis saves:
• 4 million m³ of groundwater by substituting with surface water,
• 586,000 tonnes of CO₂ emissions,
• 62,000 tonnes of residual materials, which are recycled rather than wasted,
• Since 2015, CO₂ emissions within the industrial symbiosis have been reduced by 80%, and today the local energy supply is carbon neutral (Kalundborg Symbiosis, 2022).
Source: Kalundborg Symbiosis
By integrating methane fermentation into this ecosystem, Kalundborg Symbiosis demonstrates the real-world potential of circular bioeconomy models and serves as an inspiring example for other countries. It clearly demonstrates that methane and other industrial side-streams can be effectively shared among partners and used as valuable inputs for protein production in global feed markets. In addition, collaboration between member companies reduces waste, prevents emissions, benefits the local community, and strengthens the competitiveness of the entire cluster. This synergy highlights an important point: The transition to circular systems cannot be achieved by one company alone. It requires collaboration across industries and sectors (Figure 2).
THE GLOBAL IMPACT OF INDUSTRIAL SYMBIOSIS ON FOOD SYSTEMS
The significance of the Kalundborg Symbiosis goes beyond Denmark or Europe. It speaks to a broader transformation underway in global food systems. The challenges with protein supply are global in scope, but so are the opportunities. Countries dependent on protein imports could benefit from local production of alternative proteins, reducing vulnerability to price swings and supply disruptions. Regions facing land or water scarcity could use methane fermentation to produce protein without competing with food crops, and industries seeking to decarbonize could derive new value from their emissions through circular bioeconomy applications (FAO, 2021; WEF, 2019).
Source: Kalundborg Symbiosis
LOOKING AHEAD: SCALING CIRCULAR PROTEIN SOLUTIONS
The potential of alternative proteins is vast, but realizing it requires scale, policy support, and continued innovation. Scaling production is essential: fermentation technologies need to be deployed at larger volumes and across more regions to make a meaningful impact on global protein supply. Policy and regulation also play a crucial role, as governments can accelerate adoption by supporting circular bioeconomy models, incentivizing methane capture, and creating clear regulatory pathways for novel proteins.
Simultaneously, market acceptance is key. Feed and food producers must be confident in the quality, safety, and cost-effectiveness of alternative proteins, and early partnerships will be critical in building trust. Beyond this, innovative ecosystems demonstrate how industrial collaboration can enhance efficiency and reduce emissions, and replicating these models in new contexts could unlock significant opportunities.
These approaches provide both inspiration and practical solutions as the global food system seeks sustainable growth.
CONCLUSION
The world needs to rethink protein production if it is to feed a growing population sustainably. Alternative proteins, grounded in circular bioeconomy principles, provide a powerful way forward. They reduce waste, improve resource efficiency, and create more resilient food systems.
One example is the integration of methane fermentation into industrial symbiosis networks, where emissions and byproducts from one industry become valuable resources for another. This approach demonstrates how collaboration and circular models can be brought to life in practice, turning challenges such as methane emissions into opportunities for sustainable food and feed production.
As demand for protein continues to grow and the world seeks climate-smart solutions, these innovations illustrate how technology, resource efficiency, and cross-sector partnerships can come together to deliver real impact. Alternative proteins are not a distant future. They are already here, reshaping global food systems for the better.
References
1. FAO (2013). Tackling Climate Change Through Livestock. Food and Agriculture Organization of the United Nations
2. FAO (2020). The State of World Fisheries and Aquaculture
3. FAO (2021). World Food and Agriculture Statistical Yearbook
4. IPCC (2021). Climate Change 2021: The Physical Science Basis
5. Kalundborg Symbiosis (2022). Annual Report
6. OECD (2018). The Circular Bioeconomy: A Policy Brief
7. World Bank (2019). Climate Change and Agriculture: A Review of Impacts and Adaptations
8. World Economic Forum (2019). Meat: The Future Series – Alternative Proteins
9. WWF (2021). Deforestation Fronts: Drivers and Responses in a Changing World
About Eleni Ntokou
As the NPD, Sustainability & Regulatory Affairs Director at Unibio A/S, Eleni Ntokou leads cross-functional teams to drive sustainable product development and regulatory strategies. With a PhD in Microbiology and extensive expertise in protein applications, she is passionate about advancing the green transition by bringing research-based innovations from lab to market.
