Biorefinery of Microalgae for Nonfuel Products

Abstract Microalgae have been considered as valuable feedstock due to their versatile biorefinery applications. They have the ability to sequester CO2, valorize waste materials, and recover resources from wastewater. Microalgae biomass is a rich source of carbohydrates, protein, and lipids, which can be converted into a wide variety of bioproducts. In the past few years, microalgae biomass has been extensively experimented for biofuels production. However, the sustainability of microalgae-based biofuels production is still questionable. It ignites a debate to revisit the scope of microalgae and rationalize it with future biorefinery goals. It is an opportunity to delimit the use of microalgae biomass and exploit its use for other interesting applications. It has been realized that the use of microalgae as food and feed source has an appeal. Microalgae species offer diverse biomass composition and nutritional products. Some microalgae species are rich in protein, while the others contain an appreciable amount of carbohydrate. In addition to the use of microalgae biomass as a food and feed source, they are recognized as a remarkable source of coproducts. Coproducts are the bioproducts obtained from the microalgae biomass but in trace amount. Microalgae coproducts include β-carotene, β-1,3-glucan, chlorophyll, phycobiliprotein, lutein, polysaccharides, phycocyannin, fucoidans, agar, alginates, etc. This study aims to envision the use of microalgae as food, feed, and coproducts. It underlines the importance of coproducts, provides a perspective to improve their yield, and outlines a strategy to integrate it with current environmental techniques. This study can be helpful to evaluate the sustainability attributes of microalgae biorefinery to shift focus from fuel to food, feed, and other coproducts.