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.
