Partitioning and purification of cellulases in aqueous two-phase system

Abstract

Aqueous two-phase systems can be formed by mixing the solutions of two mutually incompatible polymers or polymer and salt above critical concentrations and represent media that are very well suited for the separation and purification of biomolecules. The basis of separation is uneven distribution of biomolecules between two phases both having high water content. This so-called biocompatibility of phases allows preservation of biomolecules’ native structure while the presence of polymer can even improve their stability. Partitioning is governed by numerous factors that can be manipulated to achieve desired separation and purification results, which makes aqueous two-phase system very flexible for application. Cellulases, enzymes belonging to family of glycosyl hydrolases, play key role in organic carbon turnover and have important and wide application in industry. Extraction of enzymes in aqueous two-phase systems has been recognized as useful technique in downstream processing for their isolation and purification. In this study, partitioning of cellulases in polyethylene glycol/dextran and polyethylene glycol/salt two-phase systems was investigated with the aim to determine the most appropriate molecular weight of polymers, kind of salt and concentration of aqueous two-phase constituents at which the highest possible yield and purification factor in the top phase can be achieved.