Expérimental et théorique
In the context of climate change, to achieve carbon neutrality, we need not only to reduce our CO2 emissions, but also to capture atmospheric CO2. Cyanobacteria and microalgae are photosynthetic microorganisms with great potential, accounting for half of all photosynthesis worldwide. Moreover, they absorb CO2 more efficiently than plants during growth. They are being extensively studied with a view, among other things, to the production of third-generation biofuels. However, their CO2 capture potential has been less well studied. In the scientific literature, there are in fact two methods for measuring CO2 uptake by microorganisms: a "biological" method consisting in weighing the biomass obtained, and a "physical" method in which the evolution of the CO2 level in the gas phase above the solution containing the microorganisms is measured. We propose to combine these two methods in order to quantify precisely the quantity of carbon stored in the biomass, something that has been done very little to date. The experiment we are planning involves tracking the evolution over time of the carbon stored in the biomass, solution and gas, enabling us to measure CO2 uptake precisely, while tracing the growth curve of the microorganisms. To this end, we have built a new custom photobioreactor. The intern's job will be to carry out experiments using this photobioreactor with the cyanobacterium Synechoscystis PCC6803, while building a model to interpret the results obtained.