作　　者： ; ; ; ; ;

机构地区： 华南理工大学轻工与食品学院轻化工研究所

出　　处： 《华南理工大学学报（自然科学版）》 2006年第3期111-116,共6页

摘　　要： 使用硫酸铵分级沉淀、Sephadex G-25凝胶色谱脱盐和Sephadex G-100凝胶色谱等分离纯化技术，从康氏木霉（Trichoderma Koningii）发酵液中分离出木聚糖酶，纯化后的木聚糖酶经十二烷基硫酸钠一聚丙烯酰胺（SDS-PAGE）凝胶电泳鉴定为单一组分，其相对分子质量为55208．所得的木聚糖酶的最适反应温度为65℃，pH值为6．0．该酶稳定性较好，在30—60℃下放置2h能保持83％以上的酶活；在3．0-10．0的pH值范围内能保持85％以上的酶活．研究表明：金属离子Ba^2＋，Pb^2＋，Fe^2＋，Fe^2＋，Al^3＋和高浓度（12mmol/L）的Cu^2＋对木聚糖酶的活性有抑制作用，而Ca^2＋，Zn^2＋和4mmol／L的Cu^2＋对该酶反应有促进作用．该木聚糖酶作用于Birchwood木聚糖的米氏常数为5．37g/L，最大反应速率为0．94μmol／min． Xylanase was separated and purified from a culture filtrate of Trichoderma Koningii through ammonium sulfate precipitation, Sephadex G-25 and Sephadex G-100 column chromatography. The purified xylanase was then proved by SDS-PAGE to be a single composition with a relative molecular mass of 55 208. Good thermostability of xylanase with an optimal activity at 65 ℃ and pH 6.0 was also revealed. The results show that more than 83% or 85% of the relative activity of xylanase can be remained when respectively stored at 30 - 60 ℃ for 2 h or in the pH range of 3.0 - 10.0. Moreover, Ba^2＋ , Pb^2＋ , Fe^2＋ , Fe^2＋ , Al^3＋ and 12mmol/L Cu^2＋ are strong inhibitors to xylanase, while Ca^2＋ , Zn^2＋ and 4mmol/L Cu^2＋ are stimulators. The Michaelis-Menten constant of xylanases in the enzymatic hydrolysis of birchwood xylan is 5.37 g/L, and the maximal reaction velocity is 0.94 μ mol/min.

关 键 词： 木聚糖酶 康氏木霉 分离 纯化 酶活

领　　域： [生物学]