中文摘要：

采用0．2mol／L磷酸盐缓冲溶液匀浆法从圆蘑菇中提取多酚氧化酶（PPO），并对该多酚氧化酶的酶学特性进行研究。实验结果表明，以邻苯二酚为底物，该酶的最适pH为6．4，最适温度为30℃，Km值为0．0323mol／L，Vmax值为0．0164U／min．100℃热处理1．5min可完全钝化PPO的活力，10mmol／L的EDTA、L-半胱氨酸或柠檬酸亚锡二钠能有效抑制PPO活力。

英文摘要：

The polyphenol oxidase （PPO） of round mushroom was extraeted by 0.2 mol/L phosphate buffer and its properties was analysed. Experimental results showed that the optimal pH and temperature were 6.4 and 30 ℃ respectively, and the Km value and Vmax value with eateehol substrate were 0.032 3 mol/L and 0.016 4 U/rain respectively, and the PPO would be inactive in 1.5 min when the water tempreture was 100 ℃. EDTA, L- Cysteine or disodium stannous eitrate were strong inhibitors, the effective concentrations of the three kinds of inhibitors were 10 mmol/L.