A biochemically based structured model for phytoplankton growth in the chemostat

In this paper, a new model of phytoplankton growth in the chemostat is proposed. First, we give a description of the chemostat and we recall the main models: the simple Monod model, experimentally validated for bacteria growth and the Droop model, which is validated for phytoplankton growth and takes into account the possible nutrient storage. Though our model is quite similar to the Droop one, our approach is based on biochemical mechanisms and not on empirical observations. We study two versions of the model: one taking into account cell mortality; the other not. The main result is the global asymptotic stability of the equilibrium, ensuring survival of the cells under some hypotheses. The paper ends with some illustrative simulations and a comparison with the dynamic energy budget modelling approach.