关键词: 过氧化物酶, 纯化, 双水相萃取, 双酚A, 深山含笑

Abstract: Michelia maudiae Dunn is evergreen arbor species with high ornamental value.The leaves will gradually withered and can’t achieve its economic value when the old and new leaves update.It was found that the leaves of M.maudiae Dunn have the peroxidase activity in the previous studies.Regarding the compelling effect of peroxidase in process of phenols biodegradation,the purification and properties of the peroxidase from the leaves of M.maudiae Dunn were studied to fully develop the value of the leaves and to improve the resource utilization efficiency.Based on that,its function of removing bisphenol A was further investigated．The results showed that,after extracted by Tween-80,aqueous two-phase extraction,and DEAE-Sepharose Fast Flow ion-exchange chromatography,the yield of bound peroxidase purified from the leaves of M.maudiae Dunn was 19%,and purification fold compared with soluble peroxidase was 55.2 with specific activity of 18 999 U/mg.The optimal pH for the substrate of guaiacol was 4.5.The optimal temperature was 50 ℃.The activity of the enzyme can be maintained for a long time below 60 ℃ (good thermal stability).M.maudiae Dunn leaves peroxidase has good scavenging ability on BPA.Under the conditions of pH4-7,30-40 ℃ and reach the ratio of  H₂O₂ /BPA to 0.8,the clearance rate of 0.2 mmol /L BPA derivatives for 10 000 U/L M.maudiae Dunn leaves peroxidase was 90% in 3 hours later.M.maudiae Dunn leaves peroxidase had convincing future in researches of phenols biodegradation．

Key words: peroxidase, purification, aqueous two-phase extraction, BPA, Michelia maudiae Dunn