Microalgae cocultures: concepts and applications

Microalgae are increasingly recognized as a feedstock to enable sustainable processes and products for a wide range of applications in several fields. In nature, microalgae predominantly exist alongside other microorganisms in communities, with associated benefits. This natural phenomenon of coexistence can be engineered in coculture systems, where two or more microorganisms are cocultivated to maximize gains in productivity and/or desired responses. Microalgae coculture systems can be an efficient and economic strategy that focuses on interaction between the primary species of microalgae and other microbes, including other microalgae species, bacteria, and fungi. In a simple construct, coculture interactions aim to increase algal biomass and/or productivity of components such as carbohydrates, proteins, and lipids that can be used as substrates for subsequent processes in various applications. In this chapter, we aim to elaborate on the conceptual framework of establishing cocultures, followed by emerging applications of microalgae cocultures in diverse fields. The challenges and opportunities associated with integrating cocultures in production facilities are discussed. This chapter aims to inform and inspire further research and development in this innovative field.