title: Extraction and purification of wheat-esterase using aqueous two-phase systems of ionic liquid and salt.
abstract: To explore a new and simple rapid extraction and purification technique for wheat-esterase, an ionic liquids (ILs)-based aqueous two-phase system (ATPS) was developed for the purification of wheat-esterase from wheat extracts. Effects of various process parameters such as the concentrations of [Bmim]BF4, the types and concentrations of phase-forming salt, the system pH and the temperature on partitioning of wheat-esterase were evaluated. The obtained data indicated that wheat-esterase was preferentially partitioned into the ILs-rich phase and the ATPS composed of 20 % [Bmim]BF4 (w/w) and 25 % (w/w) NaH2PO4(pH = 4.8) showed good selectivity on wheat-esterase. Under the optimum conditions, wheat-esterase was purified with an acceptable yield (88.93 %), but produced wheat-esterase was 4.23 times as pure. It was obvious that temperature shows little influence on the purification between 10 and 50 °C. Sephadex G-150FF revealed that the band intensity of contaminating proteins in ATPS fraction almost disappeared. Therefore, ILs-based ATPS was an effective method for partitioning and recovery of wheat-esterase from wheat crude extracts.
authors.affiliation: Department of Applied Chemistry, Northeast Agricultural University, Harbin, China 150030.
authors.forename: Bin
authors.initials: B
authors.lastname: Jiang
authors.affiliation: Department of Applied Chemistry, Northeast Agricultural University, Harbin, China 150030.
authors.forename: Zhibiao
authors.initials: Z
authors.lastname: Feng
authors.affiliation: Department of Applied Chemistry, Northeast Agricultural University, Harbin, China 150030.
authors.forename: Chunhong
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Applied Chemistry, Northeast Agricultural University, Harbin, China 150030.
authors.forename: Yingcao
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Applied Chemistry, Northeast Agricultural University, Harbin, China 150030.
authors.forename: Dongmei
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Applied Chemistry, Northeast Agricultural University, Harbin, China 150030.
authors.forename: Guo
authors.initials: G
authors.lastname: Ji
keywords: Aqueous two-phase system; Ionic liquid; Purification; Wheat-esterase