Microalgae as Cell Factories: Food and Feed-grade High-value Metabolites

Microalgae, as a huge group of photosynthetic autotrophs with more than ten phyla and hundreds of promising strains growing in almost all habitats, can be used as cell factories for the production of valuable compounds. These compounds can be used as human food or animal feed. Naturally, some microalgae strains can accumulate lipids, proteins, carbohydrates, pigments, vitamins, and phytosterols in high concentrations that can be extracted, purified, and used in different industrial and food applications. Furthermore, some microalgae in response to stressed conditions or/and nutrients deficiency are able to increase productivity and accumulate these compounds. There are a lot of products in the markets worldwide nowadays in different forms such as concentrated culture, powder, tablets, and novel foods. In this chapter, all of these points will be discussed in detail.