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树脂吸附法固定Candida rugosa脂肪酶 总被引:1,自引:0,他引:1
Candida rugosa脂肪酶具有优良的催化性能,对其进行固定化可以很方便地实现酶的回收和再利用。采用南开大学化工厂生产的4种阴离子交换树脂和4种大孔吸附树脂为载体,对来源于Candida rugosa的脂肪酶进行了吸附固定化,结果表明,以大孔吸附树脂AB-8为载体的固定酶比活性最高。固定化酶制备过程中缓冲液的最适宜pH值为7.2,最佳固定化时间为1 h,载体和酶的最佳质量配比为10∶1。与游离酶相比,固定化后酶活损失大约30%,但稳定性平均约提高60%。 相似文献
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固定化黄孢原毛平革菌木素过氧化物酶的研究 总被引:1,自引:0,他引:1
用大孔吸附树脂进行黄孢原毛平革菌来源的木素过氧化物酶固定化试验,筛选出固定化效果较好的XAD7HP大孔树脂,研究了其固定化条件。结果表明,当树脂1.0g,酶液pH4.5,加酶量87.2U,吸附温度25℃,吸附4h,戊二醛质量分数0.2%,戊二醛处理时间120min,可获得最佳的固定化效果,固定化酶活力可达到16U/g(对载体)。 相似文献
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CALB脂肪酶的固定化及其拆分2-辛醇的研究 总被引:2,自引:2,他引:0
以AB-8、HZ-841、HZ-802三种大孔树脂做载体,采用物理吸附法,制备出固定化南极假丝酵母脂肪酶(CALB),并用其进行了拆分2-辛醇的研究。其中AB-8树脂做载体拆分效果最佳,其蛋白吸附量为37.94 mg/g树脂,吸附率94.86%,转酯化酶活3 000 U/g固定化酶,对映体选择性E=104。单因素优化实验得到的最佳拆分条件为:温度40℃,加酶量2.67 g/L,底物醇浓度3.76 mol/L。在该条件下,产物转化率可达50%,e.ep为97.8%。固定化pH在5.0~9.0内对拆分效果无显著影响。 相似文献
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目的以大孔树脂D380为载体,戊二醛为交联剂,进行硫酸软骨素裂解酶(ChSase)的固定化,并考察固定化酶的酶学性质。方法分别考察加酶量、吸附温度、吸附时间、吸附pH值、戊二醛交联浓度、交联时间及交联温度对ChSase固定化效果的影响,并分析该固定化酶的最适反应温度、最适反应pH值、米氏常数(Km)及其操作稳定性。结果ChSase的最佳固定化条件为:加酶量150U/g树脂,吸附温度15℃,吸附时间6h,吸附pH值7.0,戊二醛交联浓度0.01%,交联时间3h,交联温度4℃。以此条件制备的固定化酶,其酶结合效率可达79.1%。该固定化ChSase的最适反应温度为45℃;最适反应pH值为7.0;Km达1.46×10-1g/L,较游离酶高;具有较好的操作稳定性。结论以大孔树脂D380为载体固定化ChSase是可行的,所得固定化酶有较高的使用效率和稳定性,适合于工业化生产。 相似文献
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一种选择性拆分布洛芬对映体的固定化脂肪酶 总被引:3,自引:1,他引:2
为了提高扩展青霉TS414脂肪酶(PEL)对布洛芬的拆分效率,建立了适于非水相中选择性拆分(R,S)-布洛芬的固定化方法. 结果表明,固定化介质的类型、冻干pH和外加水量等因素对固定化PEL酶促拆分(R,S)-布洛芬有较大影响. 在冻干pH为9.0、外加水量为0、以大孔吸附树脂AB-8为固定化载体的体系中,40℃反应30 h后,拆分反应的转化率可达47%,对映体过量值eeP可达98.75%. AB-8固定化后,PEL在有机相反应体系中的分散性得到了明显改善,大幅度提高了酶促拆分反应的效率;大孔吸附树脂AB-8固定化PEL具有较高的操作稳定性,连续10批拆分反应的平均转化率在47%以上,eeP值均稳定在98%以上. 相似文献
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固定化假丝酵母99-125脂肪酶催化酯化脂肪酸低碳醇酯反应条件的研究 总被引:9,自引:2,他引:9
以硅藻土和纺织品为载体 ,采用吸附法制备固定化脂肪酶 ,研究了固定化假丝酵母 99 1 2 5脂肪酶在有机溶剂中催化脂肪酸低碳醇酯酯化合成过程中 ,有机溶剂性质、脂肪酸与低碳醇的结构、pH值、反应温度和体系含水量、低碳醇的抑制作用等因素对酯化过程的影响。试验结果表明 :底物低碳醇需要采用流加方式加入体系 ,石油醚是最适宜的有机溶剂 ,脂肪酸与醇的碳链越长 ,越易于酯化 ;固定化脂肪酶对直链醇的选择性优于支链醇。以石油醚为有机溶剂 ,在反应温度为 40℃、pH值为 7时 ,硬脂酸与甲醇的酯化率达 95 % ;反应后期应除去体系中的水以避免酶失活。固定化酶间歇催化油酸与甲醇的酯化时 ,重复使用 1 5次 (每次 2 4h) ,其操作半衰期约为 360h。 相似文献
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脂肪酶固定化及催化酯化反应 总被引:11,自引:1,他引:11
本研究报道了利用吸附法和化学键合法将白地霉脂肪酶固定化于五种载体上,用吸附法固定化的脂肪酶保持了高的活性。在有机溶剂中,固定化酶催化了长链脂肪酸与醇的酯化反应,酯化率可达94%。固定化过程并未改变脂肪酶的选择性。固定化脂肪酶可重复使用。 相似文献
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Koji Nakane Toshiki Hotta Takashi Ogihara Nobuo Ogata Shinji Yamaguchi 《应用聚合物科学杂志》2007,106(2):863-867
Polyvinyl alcohol (PVA)‐nanofibers‐immobilized lipase were formed by electrospinning. The specific surface area of the nanofiber (5.96 m2/g) was about 250 times larger than that of PVA‐film‐immobilized lipase (0.024 m2/g). The PVA‐nanofibers‐immobilized lipase were used as the catalyst for the esterification of (Z)‐3‐hexen‐1‐ol (leaf alcohol) with acetic acid in hexane. The activity of the nanofiber is equivalent to that of commercially available immobilized lipase (Novozym‐435). The ester conversions of the nanofibers, Novozym‐435, the film and lipase powder reached 99.5% at 5 h, 100% at 5 h, 11.5% at 6 h, and 81.1% at 5.75 h, respectively. The nanofibers‐immobilized lipase showed higher activity for the esterification than the film‐immobilized lipase and lipase powder, probably because it has high specific surface area and high dispersion state of lipase molecules in PVA matrix. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 相似文献
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Luciana Santibáñez Lorena Wilson Andrés Illanes 《Journal of the American Oil Chemists' Society》2014,91(3):405-410
Synthesis of ascorbyl palmitate by enzymatic esterification of palmitic acid and ascorbic acid was conducted in an organic medium with Pseudomonas stutzeri lipase TL immobilized in different supports and its performance was compared with commercial Novozym 435 lipase used as a reference. The enzyme was immobilized in different supports and the best catalyst was selected in terms of immobilization yield and mass specific activity to perform the reactions of synthesis. Synthesis of ascorbyl palmitate was optimized considering temperature, substrate molar ratio and enzyme to limiting substrate mass ratio as variables, and substrate conversion and specific productivity as evaluation parameters. The best reaction conditions for immobilized lipase TL were 55 °C, 1:5 ascorbic to palmitic acid molar ratio, and 1:10 lipase to ascorbic acid mass ratio, obtaining 57 % substrate conversion and a specific productivity of 0.013 [g ascorbic acid/(g enzyme × min)]; the best conditions for Novozym 435 were 70 °C, ascorbic to palmitic acid molar ratio 1:10, and 1:10 lipase to ascorbic acid mass ratio, obtaining 51 % substrate conversion and a specific productivity of 0.016 [g ascorbic acid/(g enzyme × min)]. 相似文献
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用葡萄糖酸对Fe3O4磁性纳米颗粒表面进行修饰,然后用水溶性碳化二亚胺(EDC)作偶联剂,对脂肪酶进行固定化。考察了偶联剂浓度、给酶量和反应时间对脂肪酶固定化过程的影响。结果表明,制备功能化磁性颗粒固定化酶的最佳条件为:偶联剂浓度为12.5mg/mL磷酸缓冲液(PBS),给酶量为2.5mg/mLPBS,反应时间为24h。固定化脂肪酶表现出优异的热稳定性,60℃时酶活为游离酶的6倍。重复使用10次后,酶促活力依然保持80%以上。 相似文献
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Muneharu Goto Hidetaka Kawakita Kazuya Uezu Satoshi Tsuneda Kyoichi Saito Masahiro Goto Masao Tamada Takanobu Sugo 《Journal of the American Oil Chemists' Society》2006,83(3):209-213
A porous anion-exchange hollow-fiber membrane was prepared by radiation-induced graft polymerization and chemical modification
to immobilize lipase for enzymatic reaction in an organic solvent. The amount of anion-exchange group introduced to the porous
hollow-fiber membrane was 2.5 mol/kgfiber. A lipase solution was allowed to permeate through the porous anion-exchange hollow-fiber membrane, and lipase molecules
that adsorbed onto the grafted polymer brush were cross-linked with glutaraldehyde. The lipase was immobilized at a density
of 0.14 kglipase/kgfiber, which was equivalent to a degree of multilayer binding of 20. Esterification was carried out by passing a solution of lauric
acid and benzyl alcohol in anhydrous issoctane through the lipase-immobilized membrane, and lipase activity was determined.
A reaction percentage of 50% was achieved at space velocity 68 h−1. The maximum immobilized lipase and native lipase activities were 8.9 and 0.38 mol/(h·kglipase), respectively. Thus, the activity of the immobilized lipase was 23.4 times higher than that of the native lipase. 相似文献
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Ariela V Paula Daniele Urioste Julio C Santos Heizir F de Castro 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2007,82(3):281-288
Polysiloxane–polyvinyl alcohol hybrid matrix was prepared by a sol–gel technique and its capacity to bind porcine pancreatic lipase investigated. The loading of 250 units g?1 support was shown to be effective, resulting in an immobilized lipase with high catalytic activity. Both free and immobilized lipases were characterized by determining the activity profile as a function of pH, temperature, substrate concentration and thermal stability. Application of the immobilized lipase in non‐conventional biocatalysis for the synthesis of surfactants and biodiesel was also analyzed. Production of sugar fatty acid esters was found to be dependent on the carbohydrate and the highest molar conversion (50% in 3–4 h of reaction) was achieved for substrates containing fructose and lauric or oleic acids. Biodiesel synthesis from babassu oil and ethanol, propanol or butanol was feasible and regardless of the kind of alcohols, results revealed that the immobilized PPL could efficiently convert triglycerides to fatty acid alkyl esters attaining yields varying from 75 to 95%. Copyright © 2007 Society of Chemical Industry 相似文献
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Synthesis of Fatty Acid Ethyl Ester from Acid Oil in a Continuous Reactor via an Enzymatic Transesterification 下载免费PDF全文
Nakyung Choi Yangha Kim Jeom-Sig Lee Jieun Kwak Junsoo Lee In-Hwan Kim 《Journal of the American Oil Chemists' Society》2016,93(3):311-318
Synthesis of a fatty acid ethyl ester via the lipase‐catalyzed transesterification of acid oil and ethanol was investigated in a continuous reactor. Lipozyme TL IM was employed as the immobilized lipase. This immobilized lipase derived from Thermomyces lanuginosus was purchased from Novozymes (Seoul, Korea). The acid oil was prepared by the acidification of soapstock formed as a by‐product during the refining of rice bran oil. The parameters investigated were water content, temperature, and molar ratio of substrates. The relative activity of Lipozyme TL IM was assessed during the repeated use of the immobilized lipase. The water content of the substrate had a considerable effect on the yield and the optimum water content was 4 %. The optimum temperature and molar ratio of acid oil to ethanol were 20 °C and 1:4, respectively. The maximum yield of approximately 92 % was achieved under the optimum conditions. The corresponding compositions were 92 % fatty acid ethyl esters, 3 % fatty acids, and 5 % acylglycerols. When glycerol formed during the reaction was removed by intermittent washing with ethanol, the relative activity of lipase was maintained over 82 % for a total usage of 27 cycles. For a mean residence time of 4 h, the half‐life times of Lipozyme TL IM on the control (unwashed) and treatment (washed) were 39 and 45 cycles, respectively. 相似文献