Microalgal-Based Protein By-Products: Extraction, Purification, and Applications

Microalgal bioprocesses have emerged as sustainable value-adding processes for the development of biochemicals and biomolecules for a wide range of applications to meet vital consumer needs. Microalgae-based proteins, in particular, have gained significant interest from researchers and industries because of their huge potential applications in the development of a wide range of natural products, including food additives, enzymes, nutraceuticals, and probiotics.The development of process technologies covering upstream and downstream operations for the production of intracellular and extracellular proteins from microalgae as main products or by-products is of significant interest. Research efforts are targeted at screening naturally existing microalgae cells to produce specific proteins, genetic modifications of microalgae cells to express recombinant proteins, the design of novel bioreactors with enhanced photon accessibility and hydrodynamics to optimize biomass density and protein metabolism rate, and the development low-energy and environmentally friendly extraction and purification techniques for large-scale production.This chapter reports an overview of the significance of microalgal cultivation systems for protein production as well as recent advances in the development of microalgae proteins. It discusses the bioprocess pipeline for generating proteins from microalgae biomass. This includes microalgae cultivation, harvesting, biomass disruption, and protein extraction and purification techniques to meet commercial scale production. It also presents various biofunctional applications of microalgal proteins in the cosmetic, food, and nutraceutical industries