Microalgae as feedstock for bioactive polysaccharides

Due to the increase in industrial demand for new biosourced molecules (notably bioactive exopolysaccharides (EPS)), microalgae are gaining popularity because of their nutraceutical potential and benefits health. Such health effects are delivered by specific secondary metabolites, e.g., pigments, exopolysaccharides, polyunsaturated fatty acids, proteins, and glycolipids. These are suitable for the subsequent uses in cosmetic, nutraceutical, pharmaceutical, biofuels, biological waste treatment, animal feed and food fields. In this regard, a special focus has been given in this review to describe the various methods used for extraction and purification of polysaccharides. The second part of the review provides an up-to-date and comprehensive summary of parameters affecting the microalgae growth and insights to maximize the metabolic output by understanding the intricacies of algal development and polysaccharides production. In the ultimate part, the health and nutraceutical claims associated with marine algal bioactive polysaccharides, explaining their noticeable potential for biotechnological applications, are summarized and comprehensively discussed.