可再生纳米载体固定化脂肪酶及其催化性能研究

发布时间：2018-03-04 19:57

本文选题：ZnO纳米线/大孔SiO2复合材料　切入点：吸波载体　出处：《宁波大学》2015年硕士论文　论文类型：学位论文

【摘要】：本文通过原位水热生长法将ZnO纳米线成功引入大孔SiO2的三维孔道中,得到ZnO纳米线/大孔SiO2复合材料(ZnO NWs/SiO2)。然后采用SEM和XRD对复合材料的形貌和结构进行表征。1.ZnO NWs/SiO2复合材料被用作载体通过静电吸附固定C.antarctica lipase B(CALB)。高的比表面积(233 m2/g)和强的静电作用力使得ZnO NWs/SiO2复合载体的平均吸附量达到196.8 mg/g。ZnO NWs/SiO2复合载体吸附量达到大孔SiO2的3-4倍,接近于硅基介孔材料的吸附量。ZnO NWs/SiO2-CALB浸泡在PBS缓冲溶液中48 h,ZnO NWs/SiO2的吸附量及ZnO NWs/SiO2-CALB的酶活性几乎不变。然后ZnO NWs/SiO2-CALB被用于催化拆分2-辛醇。ZnO NWs/SiO2复合载体固定化C.antarctica lipase B(CALB)催化拆分2-辛醇的最佳反应体系为:1.0 M(R,S)-2-辛醇,2.0 M乙酸乙烯酯,4.0 wt.%水含量,196.8mg/g酶负载量,60°C下反应8 h。在此条件下,ZnO NWs/SiO2-CALB催化拆分2-辛醇反应的底物转化率为49.1%,产物(R)-2-辛醇酯的对映体过量值(eep)为99%。此外,ZnO NWs/SiO2-CALB展示了较好的操作稳定性,重复使用15次后ZnO NWs/SiO2-CALB仍保留96.9%的相对活性和93.8%的相对选择性。2.ZnO NWs/SiO2作为一种新型的微波吸附材料被作为载体固定化Candida rugosa lipase(CRL)。微波辅助条件下ZnO NWs/SiO2-CRL被用于催化植物甾醇与油酸的酯化反应合成植物甾醇酯。在ZnO纳米线的存在下ZnO NWs/SiO2固定化酶的催化活性得到了较大的提高。研究证明,ZnO纳米线的微波吸附性能对微波与酶的协同作用有较大的帮助。相比传统加热,微波辅助加热条件下ZnO NWs/SiO2复合载体固定Candida rugosa lipase(CRL)展示较高的热稳定性。ZnO NWs/SiO2复合载体固定Candida rugosa lipase(CRL)在微波辅助加热条件下催化植物甾醇与油酸的酯化反应的最佳反应条件为:植物甾醇(0.1 M),酸醇摩尔比(2/1),水活度(0.11),温度(50°C),时间(1 h)。在此条件下,酯化反应的底物转化率为95.4%,得到了630-650 mg的植物甾醇酯(酶含量为20 mg)。
[Abstract]:This paper by in situ hydrothermal growth method of three-dimensional pore ZnO nanowires into the macroporous SiO2, ZnO nanowires / macroporous SiO2 composites (ZnO NWs/SiO2). Then the morphology and structure of SEM and XRD of the composite was characterized by.1.ZnO NWs/SiO2 composite materials were used as carrier C.antarctica lipase B by electrostatic adsorption and fixation (CALB). The high specific surface area (233 m2/g) 3-4 times and the strong electrostatic interaction makes the average adsorption of ZnO NWs/SiO2 composite carrier reached 196.8 mg/g.ZnO NWs/SiO2 composite carrier macroporous adsorption capacity reached SiO2, close to the silica based mesoporous materials.ZnO adsorption was soaked in NWs/SiO2-CALB PBS buffer solution h 48. The activity of ZnO NWs/SiO2 and ZnO NWs/SiO2-CALB the adsorption capacity is almost unchanged. The ZnO NWs/SiO2-CALB was then used to 2-.ZnO NWs/SiO2 octanol catalyzed resolution composite carrier immobilized C.antarctica lipase B (CA LB) the optimal reaction system for 2- octanol catalyzed resolution: 1 M (R, S) -2- octanol, 2 M acetate, 4 wt.% water content 196.8mg/g, enzyme loading, reaction conditions in 8 h. 60 ~ C, ZnO NWs/SiO2-CALB 2- octanol catalyzed resolution reaction substrate conversion rate is 49.1%, the product (R) -2- octyl ester enantiomeric excess (EEP) for 99%. ZnO in addition, NWs/SiO2-CALB shows good operational stability, repeated use of relative activity after 15 ZnO and 93.8% NWs/SiO2-CALB still retained 96.9% of the relative selectivity of.2.ZnO NWs/SiO2 as a new type of micro wave absorbing material was used as the carrier for immobilization of Candida rugosa lipase (CRL) under microwave irradiation. ZnO NWs/SiO2-CRL was used in the esterification synthesis of phytosterol esters of sterols and oleic acid catalytic plant. The catalytic activity of ZnO NWs/SiO2 immobilized enzyme in the presence of ZnO nanowires have been greatly improved. Proved that the synergistic effect of microwave adsorption properties of ZnO nanowires on microwave and enzyme are helpful. Compared with conventional heating, microwave heating under the condition of ZnO NWs/SiO2 Candida rugosa lipase fixed carrier composite (CRL) thermal stability of.ZnO NWs/SiO2 composite carrier show higher fixed Candida rugosa lipase (CRL) reaction conditions in microwave assisted heating conditions catalyzed by phytosterols and oleic acid as plant sterols (0.1 M), molar ratio of acid to alcohol (2/1), water activity (0.11), temperature (50 degrees C), time (1 h). Under this condition, the esterification reaction of the substrate conversion rate was 95.4%, 630-650 of phytosterol esters Mg (the enzyme content was 20 mg).

【学位授予单位】：宁波大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1;Q814.2

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