Study on the separation of Bromelain using aqueous two-phase extraction

Aqueous two-phase extraction is a new bioseparation technique developed in recent years. This bioseparation technique has many advantages such as higher biocompatibility, fewer separation procedures, milder operating conditions, easier engineering amplification, less residue of organic solvents in the product and so on. It has been widely used to purify different enzymes, nucleic acids,.growth hormones and bioactive components in many plants. The separation of bromelain using PEG/(NH4) 2SO4 two-phase system is discussed in this paper. The effects of PEG (poly ethylene glycol) with different molecular weight and concentration, the concentration of (NH4) 2SO4 and NaCl, for the distribution balance in two phases were studied in details. The suitable extraction conditions are 17% PEG1000, 14% (NH4) 2SO4, pH 7.0, 0.011 mol/L NaCl, and the distribution coefficient of K =3.43, the yield of 85.3% are obtained at room temperature.