果胶酶在磁性复合载体上的固定化及其酶学性质  

Immobilization and enzymological property of pectinase on the magnetic composite support

作　　者：林建城[1] 陈越丽 

机构地区：[1]莆田学院环境与生物工程学院,福建莆田351100

出　　处：《食品工业科技》2015年第14期220-224,228,共6页Science and Technology of Food Industry

基　　金：福建省高校服务海西重点建设项目(2008HX02);福建省教育厅资助省属高校科研基金项目(JK2012046)

摘　　要：通过Fe3O4磁核与海藻酸钠明胶制备磁性复合载体,戊二醛交联后协同对果胶酶进行固定化,并研究固定化酶的酶学性质。利用正交实验优化固定化酶的制备条件,比较研究了固定化酶与溶液酶的酶学性质。结果表明：在Fe2＋（5mol/L）∶Fe3＋（5mol/L）体积比为0.75∶1的溶液中,制备Fe3O4磁核;3.5%海藻酸钠与3.0%明胶以2.5∶1的体积比,加入3.0mg/m L Fe3O4磁核量,在体积分数4.0%的戊二醛中交联2.5h;以每克载体加入20mg果胶酶,p H4.0下固定60min,制备的固定化果胶酶活力回收率可达78.69%。固定化果胶酶最适p H为4.0,在p H3.0～7.0内稳定;最适温度50℃,在20～50℃具有较好的热稳定性;表观米氏常数Kmapp为3.162mg/m L;重复使用10次后,酶活力还剩51%,4℃下储存10d,酶活力还保留81%。说明以戊二醛交联磁性海藻酸钠明胶为复合载体制备的固定化果胶酶,机械强度大、弹性好,酶活力回收率高,操作稳定性好。The magnetic microspheres were prepared with Fe304 magnetic nucleus and sodium alginate-gelatin. Pectinase was immobilized while magnetic microspheres were crosslinked with glutaraldehyde. The preparation conditions of immobilized pectinase were optimized through orthogonal experiments based on single factor, and the properties of immobilized enzyme were investigated. The results showed that Fe304 magnetic nucleus could be made out when Fe2＋（5mol/L）：Fe3＋（5mol/L） was 0.75：1 （volume ratio）. When sodium alginate （3.5%）： gelatin （3.0%） was 2.5：1 （volume ratio）,the concentration of Fe304 magnetic nucleus was 3.0 miligram per millilitre,crosslinked with volume fraction of 4.0% glutaraldehyde for 2.5 hours,and following mixed with 20 miligram pectinase per gram supporter,the process time was one hour,pH value for 4.0,the recovery rate of immobilized pectinase activity could reach to 78.69%. The optimum pH and optimum temperature of immobilized pectinase for the hydrolysis of pectin were determined to be pH4.0 and 50~C ,respectively. The immobilized pectinase was stable in a pH range from 3.0 to 7.0 and at temperature 20~550（3. The apparent Michaelis constant of immobilized pectinase Kmapp equaled to 3.162mg/mL. The relative activity of immobilized enzyme remained 51.0% after continuous use for ten times,and that of remaining 81% after stored ten days. The results indicated the immobilized pectinase prepared with composite support were good enough for the strength,the flexibility and the recovery rate,and had good operation stability.

关 键 词：磁性复合载体 果胶酶 固定化 酶学性质 

分 类 号：TS201.1[轻工技术与工程—食品科学]