5. Conclusion and outlook

In the current context of both the fight against greenhouse gas emissions and the deployment of large-scale industrial cultivation of microalgae, it seems appropriate to seek to reconcile these two issues as effectively as possible. The autotrophic growth of photosynthetic microorganisms such as microalgae and cyanobacteria requires a source of inorganic carbon, leading to requirements of several tens of tonnes of CO ₂ per hectare of culture per year. This carbon is usually supplied by gaseous means, to be transferred to the culture medium (liquid phase) where the inorganic carbon is found in various dissolved forms that can be assimilated by the micro-organisms. In this sense, there is an analogy between the cultivation of photosynthetic micro-organisms and that of heterotrophic micro-organisms based on oxygen supply (need for sufficient gas-liquid...