Aqueous two-phase systems based on cholinium salts and tetrahydrofuran and their use for lipase purification

Abstract

Aqueous two-phase systems (ATPS) formed with cholinium-based ionic liquid - ILs (or salts) are a novel, low cost, and high efficient technique for the recovery of biomolecules. This study examines the forma- tion of ATPS based on cholinium-based salts (cholinium chloride, cholinium bitartrate and cholinium dihydrogencitrate) and tetrahydrofuran (THF) for the purification of lipase from Bacillus sp. ITP-001, pro- duced by submerged fermentation. The optimum conditions for this purification were determined to be 40 wt% of THF and 30 wt% of cholinium bitartrate at 25 C. A purification factor of 130.1 ± 11.7 fold, a lipase yield of 90.0 ± 0.7% and a partition coefficient of enzyme for IL-rich phase (KE = 0.11 ± 0.01) and protein contaminants for THF-rich phase (KP = 1.16 ± 0.1) were achieved.