Prospective on the application of abiotic stresses to enhance the industrial production of exopolysaccharides from microalgae

Microalgae species are sustainable sources for diverse bioactive compounds of commercial interest. Within the framework of bioeconomy, exopolysaccharides (EPS) from microalgal sources stand out as potential high-value molecules in the cosmetic, nutraceutical, and pharmaceutical industries. Since the goal is to increase the EPS presence in those markets, prospecting potential applications through the characterization of species-structure-bioactivity relations and optimizing EPS production yields through sustainable and economically feasible strategies are needed. This graphical review addresses current strategies aimed to increase EPS production in microalgal species to reach industrial-scale production with a particular focus on the use of abiotic stress - a strategy that adversely affects cell growth performance but induces desirable changes in the metabolic profile of the microalgae requiring minor to mild modifications in already established production settings. Therefore, analysis of the stress-based approaches to increase EPS production at an industrial scale is discussed, identifying those factors with the most potential from technological and economic perspectives.