| 摘要: |
| 【目的】 研究白腐菌T.pubescens MB89漆酶固定化处理的最佳条件及其酶学性质。【方法】 采用壳聚糖、壳聚糖铜、海藻酸钠/壳聚糖和TEOS/PEG 4种载体对漆酶进行固定，测定固定化漆酶酶活性在不同温度、pH值和固定化条件处理下的变化。【结果】 白腐菌漆酶的固定化方法和最佳固定条件为：① 壳聚糖固定化漆酶(IE1)。戊二醛最佳浓度为0.4 mol/L，最适交联时间8 h，最佳给酶量1.5 mg/g；② 壳聚糖铜固定化漆酶(IE2)。CuSO4·5H2O最佳添加量为0.6 mg/g，最适络合时间10 h，最佳给酶量0.25 mg/g；③ 海藻酸钠/壳聚糖固定化漆酶(IE3)。0.2 mol/L 海藻酸钠，0.2 mol/L CaCl2，0.1 mol/L 戊二醛，0.15 mol/L 壳聚糖,最佳给酶量1.5 mg/g；④ TEOS/PEG固定化漆酶(IE4)。最适PEG分子质量为600～800，最适添加量1.5 g/g，最佳给酶量1.5 mg/g。4种固定化漆酶的酶学性质:IE1和IE4的最适温度均为60 ℃，IE2和IE3为30 ℃；IE1、IE3和IE4的最适pH值为4.5，IE2为4.0；与游离漆酶（Lac）的最适pH值相比，固定化漆酶的最适pH值均向碱性方向偏移，且固定化漆酶的酸碱稳定性、热稳定性和贮存稳定性均优于游离漆酶。【结论】 固定化酶的最适合温度、pH均受固定化载体和方法的影响，固定化漆酶的稳定性均优于游离漆酶。 |
| 关键词: 白腐菌漆酶 酶固定化 酶学性质 酶稳定性 |
| DOI： |
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| 基金项目:奥地利政府项目（2004） |
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| Immobilization and properties of laccase from a white rot fungus (T.pubescens MB89) |
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| Abstract: |
| 【Objective】 The methods and characteristics of immobilized laccase from T.pubescens MB89 were studied.【Method】 Using chiitosan,chitosan copper,alginate/chitosan and TEOS/PEG as immobilized carrier,enzyme activity was detected for characteristic study.【Result】 The best methods and fixed conditions for immobilization were:(1) Chitosan immobilized laccase (IE1):the best concentration of glutaraldehyde 0.4 mol/L, the optimum crosslinking time 8 h,the best to the enzyme 1.5 mg/g;(2) Chitosan immobilized copper (IE2),the best content of CuSO4·5H2O was 0.6 mg/g,the optimal time of 10 h,the best to the enzyme 0.25 mg/g;(3) Alginate/immobilized chitosan (IE3):0.2 mol/L sodium alginate,0.2mol/L CaCl2,0.1 mol/L glutaraldehyde,0.15 mol/L chitosan.The volume of the best enzyme was 1.5 mg/g;(4) TEOS/PEG immobilized (IE4):The optimum PEG molecular weight of 600-800,the best concentration 1.5 g/g,the best to the enzyme 1.5 mg/g.The optimum temperature of IE1 and IE4 was 60 ℃,IE2 and IE3 30 ℃.The optimum pH value for IE1,IE3 and IE4 was 4.5,IE2 4.0.IE pH stability,thermal stability and storage stability were superior to those of laccase.【Conclusion】 The optimum pH and temperature of IE vary with different immobilized carriers.The stability of IE is better than free laccase. |
| Key words: laccase enzyme immobilization enzymatic property enzyme stability |
