Review of recent applications and modifications of aqueous two-phase system for the separation of biomolecules

Biomolecules, specifically proteins, polysaccharides, and secondary metabolites are potential lead compounds due to their remarkable pharmacological properties. However, the complex molecular structure of the biomolecules makes their separation processes of great challenges. The conventional downstream processes require multistep protocols that are less efficient, high solvent consumption, expensive, time-consuming, and laborious. Hence, aqueous two-phase system (ATPS) is a reliable technique for the extraction and purification of biomolecules from a complex mixture. ATPS is an environmentally friendly, simple, cost effective, and easily scalable process. It requires a short processing time to separate biomolecules of industrial values simultaneously in a single process. Modifications have also been performed by introducing deep eutectic solvents, ionic liquids, carbohydrates, amino acids or copolymers to enhance the process efficiency with an increased yield, purity and bioactivity of recovered biomolecules. This review attempts to review the recent developed ATPSs and their efficiency to extract, isolate, and purify biomolecules such as proteins, polysaccharides, secondary metabolites and other biological substances. The review provides insights into the feasibility and reliability of ATPS for biomolecule recovery.