【作者】 马玉红；

【导师】 江波；

【作者基本信息】 江南大学 ， 食品科学， 2009， 硕士

【摘要】 本文主要研究了果糖基转移酶及过氧化氢酶的固定化,并在此基础上分别对两种固定化酶的酶学性质进行了研究。从18种离子交换树脂和吸附树脂中,筛选出固定化效果较好的大孔弱碱性苯乙烯系阴离子交换树脂D380为载体、以戊二醛为交联剂,采用先吸附后交联的方法对果糖基转移酶的固定化进行分析,并对固定化条件进行了优化,结果表明,最佳固定化条件为:加酶量为200U/g树脂,吸附pH值为6.0,吸附时间为6h,吸附温度为30℃,交联剂戊二醛浓度为0. 01% ,交联时间为6h ,交联温度为4℃,固定化酶活回收率最高可达87.6%以上。固定化果糖基转移酶的的最适温度为50～55℃,比游离酶提高了5℃;热稳定性与游离酶基本相同;最适pH6.0比游离酶提高了一个单位;pH稳定性也稍有提高;固定化酶的Km值为0.60离酶的大;固定化酶重复使用10次后残余酶活为10%左右,固定化酶和游离酶均具有较好的贮存稳定性。以一种无载体固定化技术-交联酶聚集体技术固定化过氧化氢酶,考察了交联剂浓度、交联时间、交联温度对固定化效果的影响。优化的固定化条件为:交联剂戊二醛浓度为1%、交联温度为4℃、交联时间为4h,在此条件下可达到较好的固定化效果。固定化过氧化氢酶的最适温度为40℃,与游离酶相比提高了5℃;热稳定性比游离酶稍有提高,在25～35℃范围内保温30min后,二者都可保留90%以上的酶活;游离酶与固定化酶的最适pH相同都为8;pH稳定性也稍有提高。在低聚果糖的生产中,大量副产物葡萄糖的产生阻遏了底物的转化,可通过葡萄糖氧化酶与过氧化氢酶的协调作用,消除普通低聚果糖中的葡萄糖,因此,果糖基转移酶与过氧化氢酶的固定化,为得到高纯度的低聚果糖奠定了一定基础。更多还原

【Abstract】 This paper studied immobilization of the fructosyltransferase and catalase, and then studied the properties of the immobilized enzyme respectively.Fructosyltransferase was immobilized on eighteen kinds of ion-exchange and adsorption resins, among them D380 showed the excellent result for immobilization. Then the enzyme was immobilized through cross-linkage of glutaraldehyde. The optimum conditions for the immobilization were as follows: 200U of enzyme per g wet resin, pH 6.0, 30℃, and 6 hours, respectively. The crosslinking temperature and time were 4℃and 6 h respectively, and the concentration of the crosslinking agent (glutaraldehyde) was 0.01%. The activity yield of immobilized enzyme was above 87.6%.The optimum temperature and pH of the immobilized fructosyltransferase were 50～55℃and 6.0,respectively, whereas for free enzyme,were 45～50℃and 5.0. Thermal and pH stability were both improved by immobilization comparing with the free enzyme.The Km value was 0.60M(for sucrose),which was higher than that(0.29 M)of the free enzyme.This indicated that the affinity between enzyme and substrate decreased significantly.A kind of carrier-free technology was used in the immobilization of catalase, the enzyme was aggregated first then cross-linked by glutaraldehyde. The optimum conditions for the immobilization were as follows: the concentration of the crosslinking agent (glutaraldehyde) was 1%, and the crosslinking temperature and time were 4℃and 4h respectively.The optimum temperature of free and immobilized catalase were 40℃and 35℃,respectively, optimum pH and pH stability had no significant change, the thermal stability was better than that of free catlase.High-purity of fructooligosaccharides was prepared after glucose was removed in normal products by glucose oxidase(GOD) and catalase(CAT). So the study of the immobilization of Fructooligosaccharides and Catalase will make a foundation for the production.更多还原