Papain was extracted by ionic liquid aqueous two-phase system. Firstly
the influence of concentration
pH
and temperature of ionic liquid on the activity of papain was investigated. Secondly
the effects of different ionic liquid aqueous two-phase systems
alkyl chain lengths and concentrations of the ionic liquid
dosage of papain
pH
temperature on the partitioning behavior of papain were discussed. [C4mim]Cl and [C4mim]Br systems were better than [C4mim]BF4 system in extraction of papain
and it was disadvantageous to extract papain at a high temperature (60℃ or higher). Activity recovery of enzyme reached 95.16% and purification factor reached 1.5 under the optimum conditions: [C4mim]Cl 0.25 g·ml-1
K2HPO4 0.35 g·ml-1
pH 8.0
enzyme addition 2.0 mg·ml-1
30℃. The result laid the experimental basis for further scale-up research and commercial production.