海藻酸钠-琼脂混合固定化重组右旋糖酐蔗糖酶的研究  

Alginate-Agar Immobilization of Recombinant Dextransucrase

作　　者：张洪斌[1] 伊晓楠[1] 吴定涛[1] 胡雪芹[1] 

机构地区：[1]合肥工业大学化学工程学院制药工程系,安徽合肥230009

出　　处：《食品科学》2010年第5期225-228,共4页Food Science

基　　金：安徽高校省级自然科学研究重点项目(KJ2008A067);合肥工业大学博士基金项目(GDBJ2008-021)

摘　　要：以海藻酸钠和琼脂混合物作为载体对右旋糖酐蔗糖酶固定化条件及其特性进行研究,结果表明:4%海藻酸钠和1%琼脂按1:1(V/V)混合后作为载体制备的微球固定化酶表现出持续高活力,在第6批次转化率仍在40%左右;海藻酸钠-琼脂混合载体与酶液体积比为2:1时固定化酶表现出的转化率最高;得到的固定化酶最适反应温度为40℃;最适反应pH值为5.4;最适底物质量浓度为5g/100mL蔗糖;35℃保温1h后剩余酶活力为原来的44%,固定化酶比游离酶的热稳定性好;固定化酶的动力学常数Km=0.02835mol/L。Recombinant dextransucrase was immobilized with sodium alginate and agar. The immobilization conditions and enzymological properties of the enzyme were also investigated. Results indicated that immobilized dextransucrase could retain high activity via the immobilization using 4% sodium polymannuronate mixed with 1% gelatin at the ratio of 1：1 mixing. The transformation efficiency of the immobilized dextransucrase still retained 40% after repeated transformation for 6 times. The optimal volume ratio between mixed carrier and enzyme solution was 2：1, which achieved the highest enzyme activity. The optimal reaction temperature, pH and sucrose concentration as the substrate for the immobilized recombinant dextransucrase were 40 ℃, 5.4 and 5 g/100mL, respectively. The enzyme activity remained 44% after storage at 35 ℃ for 1 h. The thermal stability of the immobilized enzyme was better than that of the free enzyme. The Km value of this immobilized dextransucrase was 28.35 mmol/L.

关 键 词：右旋糖酐蔗糖酶 固定化 海藻酸钠 酶学性质 

分 类 号：TS201.25[轻工技术与工程—食品科学]