The tremendous biotechnological potential of microalgae has been highlighted in the last decade with applications in pharmaceutical, cosmetic, food and feed industries, as well as biofuel production . Microalgae have several advantages compared to terrestrial plants, most important being the fact that they can grow with potential productivities an order of magnitude higher than terrestrial plants, without using agricultural land. Environmental impact must be further improved, however, and economic costs reduced, to make algae a realistic alternative to terrestrial plants.
A promising way to achieve this consists in moving from pure cultures of single microalgal species to mixed cultures of algae and other microorganisms. These approaches are motivated, among other things, by the observation that cultivating microalgae with probiotic bacteria has been shown to be more efficient. It partakes in a broader trend in biotechnology to exploit communities of microorganisms, instead of single microbial species, for bioproduction processes. The optimization and control of microbial communities for biotechnological purposes raises theoretical and practical challenges. While a range of mathematical and computational methods for on-line estimation, adaptive control, and optimization of process conditions have been developed in control theory over the past decades, they are often based on mathematical models of the growth of a single species in a bioreactor. In order to exploit the environmental and economic potential of consortia of algae and other microorganisms, as well as of other natural and synthetic communities, we need to generalize these methods to community-level models describing the physiology of individual species as well as their mutual interactions.
