Microalgae-based Bioproducts and Biomaterials Towards a Sustainable Circular Bioeconomy

Microalgae are renewable biological resources that play a major role in the bioeconomy for sustainable development of diversified bioproducts and biomaterials. Microalgae have a tremendous potential in producing a variety of bioactive compounds, namely lipids, proteins, polysaccharides, photosynthetic pigments, vitamins, and minerals, as a single feedstock. Furthermore, these bioactive compounds can be processed to develop bioproducts and biomaterials, such as food/feed, nutraceuticals, pigments, biofuels, bioplastics, biofertilizers, and nanoparticles. Microalgae-based multiproduct biorefining is a widely used concept with the aim of enhancing economic feasibility as well as the overall sustainability of the production process. The sustainability of microalgae cultivation is further reinforced via utilization of waste streams, such as wastewater and CO2-enriched flue gas, for nutrient recovery and carbon sequestration, with simultaneous bioremediation. Consequently, a net-zero emission carbon-neutral production process is facilitated in the development of microalgal bioproduct and biomaterial, promoting a sustainable circular bioeconomy. In this context, the present chapter focuses on the key role of microalgae in maintaining a sustainable circular bioeconomy while scrutinizing its potential within a multiproduct biorefining model. In addition, technoeconomic challenges associated with sustainable processing of microalgae for bioproducts and biomaterials, potential strategies to overcome the drawbacks, and future prospects will be discussed.