Driving Species Competition in a Light-limited Chemostat

International audienceIn this paper, we tackle the problem of microalgae selection in a continuous photobioreactor where microalgae growth is limited by light. We propose a closed-loop controlfor selecting, for a given range of light intensity, the strain with the maximum growth rate fromthe microalgae population. In particular, we are interested in strains with high growth rate forhigh light intensity, i.e.,strains with high resistance to photoinhibition. Firstly, we recall theframework of the light-limited chemostat. Then, we propose a nonlinear adaptive control whichregulates the light intensity at the bottom of the photobioreactor in monoculture. This lightis of particular interest as it defines the winner of the competition in a multispecies cultureoperated in open-loop mode. Finally, we show that the proposed controller allows the selectionof a strain of interest in the case of a culture with n species