Perspective Application of the Circular Economy in the Blue Biotechnology: Microalgae as Sources of Health Promoting Compounds

Algae belong to a wide range of photosynthetic organisms that grow in aquatic environments (rivers, oceans and lakes) [13]. They are commonly classified into microalgae (unicellular and simple multicellular structures) and macroalgae (complex multicellular structures) depending on their size and cellular organization. Microalgae are microscopic single cells which may be prokaryotic (e.g. cyanobacteria) or eukaryotic (e.g. green algae) [13]. Furthermore, they are photoautotrophic microorganisms with the ability to use solar energy, reduce inorganic carbon to organic matter and producing biomass simultaneously [4].