In the framework of environment preservation, microalgae biotechnology appears to be a promising alternative for CO2 mitigation. Implementation of advanced control strategies can be further considered to improve potential performances of these organisms. In this context, this paper proposes the implementation of predictive control combined with an on-line estimation of the Chlorella vulgaris biomass, using Total Inorganic Carbon measurements. The elaboration of interval observers for biomass estimation is first detailed. This estimation is further included in a Nonlinear Model Predictive Control (NMPC) framework considered to regulate the biomass concentration. Finally experimental results are presented which validate the proposed theoretical developments.