Periodic Reporting for period 1 - Null-ution (Creation of modular cell factory for the production of high value chemicals towards Null-pollution)
Berichtszeitraum: 2023-09-01 bis 2025-10-31
Climate change is one of the most pressing global challenges of our time and is a central priority of the European Union. It is largely driven by anthropogenic greenhouse gas emissions, particularly carbon dioxide (CO2) released from fossil fuel use, industrial processes, and waste streams -the main drivers of global warming. Reducing these emissions while maintaining economic productivity requires innovative solutions that move beyond conventional mitigation strategies.
In this context, the circular bioeconomy has emerged as a key pillar of European climate and sustainability policies. A key element of this strategy is the valorisation of waste carbon streams, such as CO2 and syngas, by converting them into valuable products rather than releasing them into the atmosphere. Biotechnology and synthetic biology offer unique opportunities to enable this transition by harnessing the ability of microorganisms to capture and convert carbon into chemicals, fuels, and materials.
The Null-ution project addresses this challenge by exploring new biological routes to transform CO2 and syngas (industrial waste gas) into useful chemicals and materials. Instead of relying on conventional biomass feedstocks, which can raise concerns related to land use and food security, and treating CO2 as a waste product, the project views CO2 as a renewable carbon feedstock that can be reused through biotechnology. The work builds on acetogenic bacteria, microorganisms naturally capable of capturing CO2 via the Wood–Ljungdahl pathway, one of the most energy-efficient carbon fixation routes known in nature.
The overall objective of Null-ution is to develop a modular microbial platform with improved carbon efficiency and reduced carbon loss, enabling the conversion of CO2 and syngas into valuable products. By combining advanced enzyme discovery, synthetic biology, and pathway engineering to identify and optimize key enzymes involved in CO2 fixation and product biosynthesis, the project aims to enable the sustainable production of bio-based materials and fuels, such as biodegradable plastics and alcohols, from gaseous carbon sources. This approach has the potential to reduce greenhouse gas emissions while supporting industrial innovation.
The project pathway to impact is based on a rational, interdisciplinary approach. Computational tools, including artificial intelligence and structural analysis, are used to guide experimental design and reduce development time. Synthetic biology techniques enable the modular assembly and testing of novel metabolic pathways, while microbial engineering provides a foundation for future scale-up and industrial translation. Together, these activities support the development of robust biological systems capable of producing sustainable chemicals, such as biodegradable polymers and biofuels, from waste carbon.
To achieve this, the project is divided into two main sections: the first being the selection of the best acetogen as well as a novel strain to capture CO2, second is the integration of computational enzyme selection, artificial intelligence–assisted analysis, and experimental synthetic biology tools. This interdisciplinary strategy allows rational design of metabolic pathways and supports scalable bioprocess development.
The expected impacts of Null-ution are scientific, technological, and societal. Scientifically, the project advances knowledge in CO2 metabolism, enzyme function, and pathway design. Technologically, it contributes to emerging carbon-utilisation technologies that can be applied across multiple industrial sectors and develops a robust workflow to identify the best enzymes and biocatalysts for biochemical production. Societally, the project supports the EU’s long-term objectives for climate neutrality, resource efficiency, and sustainable growth. By training an MSCA researcher in interdisciplinary and transferable skills, Null-ution also strengthens Europe’s human capital and capacity for excellence in sustainable biotechnology.
In this context, the circular bioeconomy has emerged as a key pillar of European climate and sustainability policies. A key element of this strategy is the valorisation of waste carbon streams, such as CO2 and syngas, by converting them into valuable products rather than releasing them into the atmosphere. Biotechnology and synthetic biology offer unique opportunities to enable this transition by harnessing the ability of microorganisms to capture and convert carbon into chemicals, fuels, and materials.
The Null-ution project addresses this challenge by exploring new biological routes to transform CO2 and syngas (industrial waste gas) into useful chemicals and materials. Instead of relying on conventional biomass feedstocks, which can raise concerns related to land use and food security, and treating CO2 as a waste product, the project views CO2 as a renewable carbon feedstock that can be reused through biotechnology. The work builds on acetogenic bacteria, microorganisms naturally capable of capturing CO2 via the Wood–Ljungdahl pathway, one of the most energy-efficient carbon fixation routes known in nature.
The overall objective of Null-ution is to develop a modular microbial platform with improved carbon efficiency and reduced carbon loss, enabling the conversion of CO2 and syngas into valuable products. By combining advanced enzyme discovery, synthetic biology, and pathway engineering to identify and optimize key enzymes involved in CO2 fixation and product biosynthesis, the project aims to enable the sustainable production of bio-based materials and fuels, such as biodegradable plastics and alcohols, from gaseous carbon sources. This approach has the potential to reduce greenhouse gas emissions while supporting industrial innovation.
The project pathway to impact is based on a rational, interdisciplinary approach. Computational tools, including artificial intelligence and structural analysis, are used to guide experimental design and reduce development time. Synthetic biology techniques enable the modular assembly and testing of novel metabolic pathways, while microbial engineering provides a foundation for future scale-up and industrial translation. Together, these activities support the development of robust biological systems capable of producing sustainable chemicals, such as biodegradable polymers and biofuels, from waste carbon.
To achieve this, the project is divided into two main sections: the first being the selection of the best acetogen as well as a novel strain to capture CO2, second is the integration of computational enzyme selection, artificial intelligence–assisted analysis, and experimental synthetic biology tools. This interdisciplinary strategy allows rational design of metabolic pathways and supports scalable bioprocess development.
The expected impacts of Null-ution are scientific, technological, and societal. Scientifically, the project advances knowledge in CO2 metabolism, enzyme function, and pathway design. Technologically, it contributes to emerging carbon-utilisation technologies that can be applied across multiple industrial sectors and develops a robust workflow to identify the best enzymes and biocatalysts for biochemical production. Societally, the project supports the EU’s long-term objectives for climate neutrality, resource efficiency, and sustainable growth. By training an MSCA researcher in interdisciplinary and transferable skills, Null-ution also strengthens Europe’s human capital and capacity for excellence in sustainable biotechnology.
The Null-ution project explored new ways to turn carbon dioxide (CO2) and gas mixtures into useful products using microorganisms. The work focused on understanding and improving how microbes can capture carbon and convert it into valuable chemicals through carefully following the metabolic pattern of the microbes under study and designing biological pathways.
A key part of the project was to identify a new acetogen that can achieve the balance between being able to quickly capture CO2 and produce the target products. This was achieved by screening different acetogens, having in mind the metabolic pattern of the tested organism and the amount of CO2 that can be captured by the microbe. Moreover, since the project aims to target future realistic integration into the industrial system, the tolerance of the organism to synthesis gas (syngas) produced from fossil fuels, such as the steel industry, natural gas, coal, and others.
Another pillar of the project was the use of advanced computer-based methods to identify enzymes that play an important role in carbon fixation and product formation. By analyzing large collections of biological data and protein structures, the project identified promising enzyme candidates that could enhance existing metabolic pathways. These enzymes were further studied using molecular simulations to better understand how they interact with their target molecules.
Based on these results, genetic building blocks were designed and assembled in a modular way, allowing different pathway combinations to be tested efficiently. Initial testing was carried out in a well-known laboratory bacterium to verify pathway functionality before future transfer into carbon-fixing bacteria. In parallel, the natural metabolism of selected Clostridium species was analysed under different conditions to understand their baseline behaviour.
Overall, the project established a clear workflow that connects computer-based enzyme discovery with experimental pathway construction. The main achievements include the identification of new enzyme candidates, the design of flexible genetic pathways, and the generation of knowledge that supports future development of microbial systems for sustainable carbon utilisation.
A key part of the project was to identify a new acetogen that can achieve the balance between being able to quickly capture CO2 and produce the target products. This was achieved by screening different acetogens, having in mind the metabolic pattern of the tested organism and the amount of CO2 that can be captured by the microbe. Moreover, since the project aims to target future realistic integration into the industrial system, the tolerance of the organism to synthesis gas (syngas) produced from fossil fuels, such as the steel industry, natural gas, coal, and others.
Another pillar of the project was the use of advanced computer-based methods to identify enzymes that play an important role in carbon fixation and product formation. By analyzing large collections of biological data and protein structures, the project identified promising enzyme candidates that could enhance existing metabolic pathways. These enzymes were further studied using molecular simulations to better understand how they interact with their target molecules.
Based on these results, genetic building blocks were designed and assembled in a modular way, allowing different pathway combinations to be tested efficiently. Initial testing was carried out in a well-known laboratory bacterium to verify pathway functionality before future transfer into carbon-fixing bacteria. In parallel, the natural metabolism of selected Clostridium species was analysed under different conditions to understand their baseline behaviour.
Overall, the project established a clear workflow that connects computer-based enzyme discovery with experimental pathway construction. The main achievements include the identification of new enzyme candidates, the design of flexible genetic pathways, and the generation of knowledge that supports future development of microbial systems for sustainable carbon utilisation.
The Null-ution project advances the state of the art in carbon dioxide (CO2) utilisation by moving beyond conventional biomass-based bioprocesses and demonstrating new biological strategies for converting gaseous carbon into valuable products. While previous research has shown that certain microorganisms can assimilate CO2, this project goes further by establishing an integrated framework that combines advanced computational design with modular synthetic biology to improve pathway efficiency and flexibility.
A key result beyond the state of the art is the development of a systematic in silico–to–experimental workflow for enzyme discovery and pathway construction. By integrating artificial intelligence–assisted enzyme screening, structural analysis, and molecular simulations, the project enables more targeted identification of enzymes suitable for carbon fixation and product biosynthesis. This approach reduces trial-and-error experimentation and accelerates the design of new metabolic pathways compared to traditional methods.
Another advancement lies in the modular design of synthetic pathways. The project demonstrates how individual enzymes and pathway components can be assembled, tested, and optimised in a stepwise and flexible manner. This modularity allows pathways to be adapted for different products or microbial hosts, extending applicability beyond a single case study such as n-butanol. In addition, the focus on gaseous feedstocks addresses limitations associated with land use and feedstock availability, offering a scalable alternative aligned with long-term sustainability goals.
The results of Null-ution have the potential to support future development of sustainable carbon utilisation technologies. To ensure further uptake and success, several needs have been identified:
- Further research and demonstration: Experimental validation of complete pathways in CO2-utilising microbial hosts and testing under industrially relevant conditions.
- Scale-up and bioprocess development: Translation of laboratory results into pilot-scale fermentation systems.
- Access to industrial partners and markets: Collaboration with industry stakeholders to identify viable application areas for bio-based products.
- IPR and innovation support: Evaluation of intellectual property opportunities related to novel enzymes and pathway designs.
- Supportive regulatory and funding frameworks: Continued support through Horizon Europe and related programmes to advance biological CO2 utilisation technologies.
A key result beyond the state of the art is the development of a systematic in silico–to–experimental workflow for enzyme discovery and pathway construction. By integrating artificial intelligence–assisted enzyme screening, structural analysis, and molecular simulations, the project enables more targeted identification of enzymes suitable for carbon fixation and product biosynthesis. This approach reduces trial-and-error experimentation and accelerates the design of new metabolic pathways compared to traditional methods.
Another advancement lies in the modular design of synthetic pathways. The project demonstrates how individual enzymes and pathway components can be assembled, tested, and optimised in a stepwise and flexible manner. This modularity allows pathways to be adapted for different products or microbial hosts, extending applicability beyond a single case study such as n-butanol. In addition, the focus on gaseous feedstocks addresses limitations associated with land use and feedstock availability, offering a scalable alternative aligned with long-term sustainability goals.
The results of Null-ution have the potential to support future development of sustainable carbon utilisation technologies. To ensure further uptake and success, several needs have been identified:
- Further research and demonstration: Experimental validation of complete pathways in CO2-utilising microbial hosts and testing under industrially relevant conditions.
- Scale-up and bioprocess development: Translation of laboratory results into pilot-scale fermentation systems.
- Access to industrial partners and markets: Collaboration with industry stakeholders to identify viable application areas for bio-based products.
- IPR and innovation support: Evaluation of intellectual property opportunities related to novel enzymes and pathway designs.
- Supportive regulatory and funding frameworks: Continued support through Horizon Europe and related programmes to advance biological CO2 utilisation technologies.