优化彩绒革盖菌产漆酶条件及染料脱色研究

Optimization of Culture Conditions for Laccase Production by Trametes versicolor and Dye Decolorization by the Crude Laccase

对一株漆酶高产白腐菌——彩绒革盖菌的培养和产酶条件，包括培养基初始pH值、金属离子Cu^2＋和Mn^2＋的含量，以及诱导剂的种类、添加量和添加时间等相关因素进行了优化。结果发现该菌种适宜在pH值3．5～5．7环境下生长并合成漆酶，培养基中添加缓冲液可以获得更高的酶活，但不加则有较高的酶产率；铜和锰可以显著提高漆酶活力，当以0．1mmol／L2，5-二甲基苯胺为诱导剂时，培养基中宜含0．008～0．08mmol／L Cu^2＋，0．01mmol／L左右的Mn^2＋。在5种常用漆酶诱导剂中，2，5-二甲基苯胺的效果最佳，且应在菌种进入对数生长期时加入效果最好，其最适添加浓度为0．4mmol／L，此时最适产酶Cu“浓度为0．4mmol／L。研究显示漆酶在30和40℃下保持6h后残余酶活分别为原来的95％和80％；60℃条件下，该酶保温1h后的残余活力仅为原来的14％。该酶的最适反应温度是65℃，最适反应pH值为2．4～3。对20种常用染料进行的脱色研究显示，在pH值5、40℃条件下，该粗漆酶液可以直接作用于13种工业染料。

Several cultural conditions for high laccase production by Trametes versicolor, including initial medium pH value, metal ions Cu^2＋ and Mn^2＋ contents, types of inducers, as well as dosage and adding time of inducers were studied and optimized. The result showed that T. versicolor suited to grow and produce laccases at pH value 3.5-5.7, and unbuffered media were able to get good laccase productivity though buffered media could get higher laccase activity. Metal ions Cu^2＋ and Mn^2＋ in the culture could remarkably increase the activity of laccases. The optimal concentration of Cu^2＋ was 0.008-0.08 mmol/L, and the optimal concentration of Mn^2＋ was about 0.01 mmol/L, when the culture contained 0.1 mmol/L 2,5-dimethoxyaniline. Among five usual revulsants 2,5-dimethoxyaniline was the best one. Its optimal concentration was 0.4 mmol/L and it should be added during the logarithmic growth phase. Under this condition, the suitable Cu^2＋ concentration was 0.4 mmol/L. Enzymatic characterization indicated that residual activity was 95 % and 80 % of the origin after 6 h maintenance at 30 and 40℃, respec- tively. After 1 h maintenance at 60℃, the activity was left 14 % of the origin. The optimal reaction temperature of laccase was 65 ℃ and the optimal reaction pH value was 2.4-3. Using the crude laccase, decolorization of 20 kinds of industrial dyes in common use were studied at pH value 5 and 40℃ and 13 kinds among them could be decolorized by the enzyme.