Biopolymers Synthesized by Microalgae Grown in Wastewater: a Technological Survey

The aim of this review is to provide a comprehensive understanding by surveying patent documents and scientific articles on current progress in obtaining biopolymers from microalgae grown in wastewater. Raising critical points, current market panorama, trends and perspectives for the implementation of the integrated microalgae biorefinery. The searches for articles and patents were carried out using the terms microalgae , algae , polyhydroxyalkanoate , polymer , and biopolymer . About 57 patents and 27 articles directly related to the topic were found. The USA is the country with the highest number of patents (32), followed by the Republic of Korea (12). Companies are the biggest depositors (50%). Currently, the focus of research is centered on increasing the efficiency of treatments, aiming at large-scale production. Scientific articles show that little has been researched on the extraction of biopolymers from microalgae grown in wastewater. The ability of microalgae to act in the bioremediation of effluents stands out, as well as in the production of bioproducts of industrial interest. However, there is a gap regarding the economic feasibility of implementing current methods to obtain biopolymers, due to the high cost of production (2 × current methods). In addition, more research must be carried out, seeking to evaluate the techno-economic scenario (focused currently on PHB) and bioprospecting new strains to implement the integrated biorefinery concept. These are strategies that could increase the profitability of this sector, and enabling the use of microalgae to obtain biopolymers from effluents is considered a key factor to promote an industrial shift.