One-pot chemo-enzymatic synthesis and one-step recovery of homogeneous long-chain polyphosphates from microalgal biomass

Abstract

SummaryAbstract FigureGraphical abstractPhosphate, an essential component of life, fertilizers, and detergents, is a finite resource that could be depleted within 70 years, while improper phosphate waste disposal in aquatic environments results in eutrophication. Despite some chemical-based methods, biological phosphorus removal using polyphosphate-accumulating organisms, such as microalgae, serves as a sustainable alternative to reclaim phosphate from wastewater. Polyphosphates have profound biological functions and biomedical applications, serving as energy stock, coagulation factors, and antiviral agents depending on their length, showing inherent value in polyphosphate recovery. Here, we leveraged the power of thermodynamic coupling and phase transitions to establish a one-pot, two-step multi-enzyme cascade to convert polydisperse polyphosphate in microalgae biomass into high-molecular-weight insoluble long-chain polyphosphates, allowing for one-step purification. We then optimzed a thermo-digestion approach to transform the 1,300-mers into shorter polyphosphates. Altogether, the processes established here enable the establishment of a sustainable P bioeconomy platform to refine microalgal biomass for biotechnological uses.