Abstract: A tea saponin decoloring enzyme (TSDE) was separated from Phanerochaete chrysosporium TS07 by using ammonium sulfate precipitation. The separated TSDE activity was 52　971 U·g-1. The effect of pH value on TSDE activity and stability was examined at pH values ranging from 30 to 100. TSDE was completely stable in a wide pH range (30-75) and presented an optimum pH value of 45. The optimum temperature for TSDE was 40℃ and the enzyme was stable at room temperature. It was also found that TSDE was strongly inhibited by Hg2+， while Fe3+, Ca2+ and Ni2+ did not cause any alteration in the activity. TSDE was also resistant to presence of up to 5% H2O2， but it was inhibited in presence of 10% H2O2. The TSDE showed a high percentage of activity in reaction mixtures containing 10% (V/V) of different organic solvents (acetone， isopropanol， ethanol and acetonitrile). The susceptibility of TSDE to inactivation by H2O2 in absence of substrate was also studied and it was found that the enzyme was very stable in presence of up to 025% H2O2．

Key words: Phanerochaete chrysosporium, tea saponin decoloring enzyme, enzyme properties