TY - JFULL AU - K. Ratanapongleka and J. Phetsom PY - 2011/10/ TI - Extraction in Two-Phase Systems and Some Properties of Laccase from Lentinus polychrous T2 - International Journal of Chemical and Molecular Engineering SP - 821 EP - 825 VL - 5 SN - 1307-6892 UR - https://publications.waset.org/pdf/11632 PU - World Academy of Science, Engineering and Technology NX - Open Science Index 57, 2011 N2 - Extraction of laccase produced by L. polychrous in an aqueous two-phase system, composed of polyethylene glycol and phosphate salt at pH 7.0 and 250C was investigated. The effect of PEG molecular weight, PEG concentration and phosphate concentration was determined. Laccase preferentially partitioned to the top phase. Good extraction of laccase to the top phase was observed with PEG 4000. The optimum system was found in the system containing 12% w/w PEG 4000 and 16% w/w phosphate salt with KE of 88.3, purification factor of 3.0-fold and 99.1% yield. Some properties of the enzyme such as thermal stability, effect of heavy metal ions and kinetic constants were also presented in this work. The thermal stability decreased sharply with high temperature above 60 0C. The enzyme was inhibited by Cd2+, Pb2+, Zn2+ and Cu2+. The Vmax and Km values of the enzyme were 74.70 μmol/min/ml and 9.066 mM respectively. ER -