Partitioning of acid protease from Penicillium roqueforti in aqueous two-phase system polyethylene glicol/phosphate

Abstract

The partitioning of acid protease produced by submerged fermentation of Penicillium roqueforti in the aqueous two-phase system polyethylene glycol/sodium phosphate was studied. In the system with 15% polyethylene glycol 4000/25% NaH2PO4 favourable partition coefficient and the top phase yield were obtained, 2.651 and 56.51%, respectively. The purification of acid protease from crude enzyme was optimized by optimizing separation factor. Completely randomized factorial design was applied and the system 15.54% PEG 4000/20% NaH2PO4 appeared to be optimal. Statistically calculated separation factor of 3.553, was similar to the experimentally obtained value (3.084), which indicates the possible application of the factorial design onto ATPS partition and purifycation.

Keywords

• Acid protease
• aqueous two-phase systems
• completely randomized factorial design
• partitioning
• separation factor