CO2 into sugars and functional food ingredients
The project aims to develop an elegant way of directly converting carbon dioxide from the atmosphere into food ingredients using cell-free systems. More specifically, this will be achieved using zeolite carbon scrubbers which will provide microalgal enzymatic extracts rich in enzymes (e.g. RuBisCO) and substrates (e.g. ribulose-1,5-bisphosphate) with concentrated CO2. The hypothesis is that these extracts, which allow plants to convert CO2 into glucose during photosynthesis, will be several times more active having more substrate to their disposal and being freed from cellular regulation mechanisms.
Novel enzyme extraction and purification approaches based on deep eutectic solvents and external fields such as acoustic and electric will be developed to preserve the structural integrity of these enzymes as well as to provide an environment where their activity is promoted and maximized. Furthermore, the other cellular components such as lipids, pigments, starch and proteins will be recovered through a multiproduct biorefinery approach. The novel insights provided by this project could provide a scalable and more sustainable source of novel food ingredients which could potentially replace current practices and help restore the climate and ecological balance on Earth.
The SweetAir proposal will circumvent these drawbacks by employing a disruptive novel approach to mildly extract the complete microalgal enzymatic cocktail and their substrates as well as energy-carrying molecules required to convert concentrated streams of CO2 into hexose sugars. This process is hypothesised to lead to significantly higher conversion efficiencies by removing the limitations typically found in the cells. The mild extraction is driven by coupling natural deep eutectic solvents (NaDES) to low-intensity external fields such as acoustic and electric. These green solvents are mixtures of solid natural compounds such as choline chloride and urea, which become liquid when mixed due to changes in their melting point. Moreover, these novel mixtures have tunable properties (viscosity, acidity and polarity) due to their different functional groups, providing them “designer” characteristics which make them excellent for specifically targeting and recovering molecules of interest.