Algal biopolymers as sustainable resources for a net-zero carbon bioeconomy

[Display omitted] •Microalgal and macroalgal polysaccharides, polyesters and composites are reviewed.•Biosynthetic pathways and degradation mechanism of the biopolymers are discussed.•Integrating wastewater treatment, biopolymer and biofuel production present a sustainable path.•Citation networks point to an emerging node on algae based single-use plastics. The era for eco-friendly polymers was ushered by the marine plastic menace and with the discovery of emerging pollutants such as micro-, nano-plastics, and plastic leachates from fossil fuel-based polymers. This review investigates algae-derived natural, carbon neutral polysaccharides and polyesters, their structure, biosynthetic mechanisms, biopolymers and biocomposites production process, followed by biodegradability of the polymers. The review proposes acceleration of research in this promising area to address the need for eco-friendly polymers and to increase the cost-effectiveness of algal biorefineries by coupling biofuel, high-value products, and biopolymer production using waste and wastewater-grown algal biomass. Such a strategy improves overall sustainability by lowering costs and carbon emissions in algal biorefineries, eventually contributing towards the much touted circular, net-zero carbon future economies. Finally, this review analyses the evolution of citation networks, which in turn highlight the emergence of a new frontier of sustainable polymers from algae.