Partitioning behavior of laccase from Lentinus polychrous Lev in aqueous two phase systems

Abstract

In the present study, an aqueous two phase system (ATPS) composed of polyethylene glycol (PEG) and potassiumphosphate was employed to purify laccase produced by Lentinus polychrous. The assessments of system parameters such asmolecular weight of the PEG, PEG concentration, phosphate salt, system pH, and neutral salt (NaCl) concentration on laccasepartitioning and purification were investigated. The enzyme preferentially partitioned in the top polymer-rich phase in alltested systems. Desirable conditions for partitioning were found in the system having polyethylene glycol of intermediatemolecular weight 4,000. This work revealed that the extraction efficiency was not much affected by PEG concentration. TheNaCl addition decreased greatly the partition coefficient of laccase. The optimal system was obtained at pH 7.0, containing12% w/w PEG 4,000 and 16% w/w potassium phosphate with enzyme partition coefficient of 88.30, purification factor of 3.01-fold, and 99.08% yield of enzyme activity in the top phase. Overall, the results obtained in this study revealed that ATPSscould be potentially useful technique for a first step purification of laccase from L. polychrous.

Keywords

• aqueous two phase system
• laccase
• partitioning
• Lentinus polychrous