Extracellular Polymeric Substances (EPS) as Microalgal Bioproducts: A Review of Factors Affecting EPS Synthesis and Application in Flocculation Processes

Microalgae are natural resources of intracellular compounds with a wide spectrum of applications in, e.g., the food industry, pharmacy, and biofuel production. The extracellular polymeric substances (EPS) released by microalgal cells are a valuable bioproduct. Polysaccharides, protein, lipids, and DNA are the main constituents of EPS. This review presents the recent advances in the field of the determinants of the synthesis of extracellular polymeric substances by microalgal cells and the EPS structure. Physical and chemical culture conditions have been analyzed to achieve useful insights into the development of a strategy optimizing EPS production by microalgal cells. The application of microalgal EPS for flocculation and mechanisms involved in this process are also discussed in terms of biomass harvesting. Additionally, the ability of EPS to remove toxic heavy metals has been analyzed. With their flocculation and sorption properties, microalgal EPS are a promising bioproduct that can potentially be used in harvesting algal biomass and wastewater management.

Automated summary

Microalgae are natural resources with intracellular compounds that have a wide range of applications in the food industry, pharmacy, and biofuel production. The extracellular polymeric substances (EPS) released by microalgal cells, mainly composed of polysaccharides, proteins, lipids, and DNA, are valuable bioproducts. Research has shown that optimization of EPS production by microalgal cells can be achieved through analysis of physical and chemical culture conditions, and microalgal EPS have great potential in flocculation and toxic heavy metal removal.