Microalgae and Cyanobacteria EPS: Producing Strains, Accumulation and Extraction Strategies, and Valorizations

Microalgae and cyanobacteria are photosynthetic organisms that can produce/accumulate biomolecules of industrial interest. Among these molecules, EPS are macromolecular polysaccharide compounds with biological activities and physicochemical properties that make them suitable for a variety of commercial markets, including cosmetics, therapeutics, nutraceuticals, and hydrocolloids. The number of strains of microalgae and cyanobacteria described to produce such EPS has increased in recent years, and a diversity of monosaccharide compositions has been discovered, underlining the versatility of these organisms. While certain production strategies can be applied to increase EPS production yields, it appears that case-by-case studies are needed to promote EPS synthesis by a strain, as numerous responses exist. This chapter reviews the diversity of EPS-producing strains of microalgae and cyanobacteria and the variability of their compositions. Polymer production and extraction strategies are also discussed. Finally, an overview of biological activities and physicochemical properties enables us to envisage their use in several commercial markets.