极耐高温木聚糖酶的Eudragit S-100固定化及其对不同纸浆的助漂作用  

Immobilization of Hyperthermophilic Xylanase from Thermotoga Maritima on the Smart Polymer Eudragit S-100 and its Application in Pulp Pre-bleaching

作　　者：李里特[1] 朱运平[1] 江正强[1] 艾志录[1] 李秀婷[1] 

机构地区：[1]中国农业大学食品科学与营养工程学院,北京100083

出　　处：《中国造纸》2005年第7期1-5,共5页China Pulp & Paper

基　　金：国家 8 63项目 (2 0 0 3AA2 1 4 0 2 0 )

摘　　要：以溶解性可以通过pH值进行调节的EudragitS 1 0 0为载体,对海栖热袍菌的极耐高温木聚糖酶B(XynB)进行固定化,并对固定化酶的性质进行了测定,初步研究了固定化酶对浆料的助漂效果。结果表明,XynB经固定化后,酶活回收率高达90 % ,且对原酶有纯化作用,固定化酶达到电泳单一带的纯度。固定化酶与游离酶相比,最适温度提高了5℃,达95℃,温度稳定性也有较大提高。可溶性固定化酶能有效作用于不溶底物,纸浆经固定化酶处理后释放出大量的还原糖,浆料卡伯值均有不同程度降低,表明固定化酶应用于纸浆助漂有很大潜力。The recombinant xylanase B （XynB） from Thermotoga maritima was immobilized on reversibly soluble-insolube enteric coating polymer Eudragit S-100.The latter was a copolymer of methacrylic acid and methyl methacrylate and a pH-sensitive smart polymer.The immobilized xylanase retained over 90% of its activity toward oat xylan as the substrate. In order to check the purification of the immobilized XynB, the elution of the enzyme was carried out in presence of 1 mol/L NaCl and 0.2% （v/v） Triton X-100,and the extract from Eudragit S-100 showed a single band at approximately 42 kDa on a 10% SDS-PAGE gel.The optimum pH value for the immobilized XynB was 6.1 and the same as the free XynB, the optimum temperature was 95℃ and 5℃ higher than that of the free XynB, meanwhile the immobilized XynB also had higher thermostability.Thus, the reversibely soluble-insoluble immobilized XynB was significant for pulp bleaching.The application of immobilized XynB in pre-bleaching of three different kinds of pulp was evaluated. A great amount of reducing sugar was released from the pulps and the decrease of the kappa number of each pulp was observed. In conclusion, immobilized hyperthermophilic XynB was a promising xylanase for pulp pre-bleaching.

关 键 词：耐高温木聚糖酶 海栖热袍菌 固定化 纸浆预漂 EUDRAGIT S-100 

分 类 号：TS745[轻工技术与工程—制浆造纸工程]