共查询到20条相似文献,搜索用时 140 毫秒
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褐色高温单孢菌PE-211纤维素酶经硫酸铵盐析、2次SephadexG-100柱纯化,粗酶液被纯化47.5倍,比活力为54.15 IU/mg,以戊二醛为交联剂制备固定化酶.酶动力学研究表明,固定化酶的最适pH为8.5,最适温度为70℃,且固定化酶在60~80℃活力较高;该酶的耐热性很强,而固定化酶的热稳定性比原酶强;以羧甲基纤维素钠为底物,固定化酶的Km为7.19 mg/mL,Vmax为0.132 mg/(mL·min). 相似文献
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分子筛固定氨基酰化酶Ⅰ的研究 总被引:2,自引:0,他引:2
以Y型分子筛为载体,分别采用吸附法、吸附-戊二醛交联法、偶联法和偶联-重氮法4种方法对氨基酰化酶I进行固定化。 研究发现偶联法获得的分子筛固定化酶的活性最高,达0.258 IUmg-1,并对分子筛固定化酶最适pH值、最适反应温度、重复使用性和米氏常数进行了测定;结果表明该载体适合氨基酰化酶I的固定,可以获得较高的酶活力,分子筛固定化酶的最适pH值、最适反应温度都有所拓宽。 相似文献
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以壳聚糖为载体固定化青霉素酰化酶的研究 总被引:12,自引:1,他引:11
介绍了以壳聚糖为载体固定化青霉素酰化酶需首先制备壳聚糖颗粒 ,使用戊二醛、甲醛、乙二醛 3种活化剂处理所得的壳聚糖颗粒 ,确定了以戊二醛为活化剂交联其上的氨基共价结合青霉素酰化酶的固定化方法。从戊二醛的浓度、pH值、固定化时间、固定化pH值、酶用量等条件摸索了最佳固定化条件 ,获得了酶活力为4 0 0 0 0U/ (g·h)、回收率为 5 0 %左右的固定化青霉素酰化酶。 相似文献
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氨基树脂固定胃蛋白酶的方法及性质研究 总被引:1,自引:0,他引:1
采用氨基树脂作为载体,戊二醛作为交联剂,对胃蛋白酶的固定化进行了研究,并对固定化条件和固定化胃蛋白酶的部分酶学性质进行了分析。确定固定条件为:戊二醛浓度为5%,载体处理温度为室温(25℃),处理时间为5h,m(胃蛋白酶):m(氨基树脂)为1:25,pH为3.0,固定时间为12h。此条件下固定化的胃蛋白酶活力为30U/g,酶的活力回收率为60%。与非固定化相比最适水解温度由50℃升高到60℃,最适pH值由2.0升高到4.0,游离酶米氏常数3.08g/L,固定化酶米氏常数1.2g/L,固定化胃蛋白酶的储存半衰期约为25天。对珠蛋白的操作半衰期为9天。 相似文献
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Jolanta Bryjak Andrzej Noworyta 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1993,57(1):79-85
The effects of glutaraldehyde, enzyme concentrations and reactants volumes, ionic strength, pH value and carrier particle diameter on immobilization of penicillin acylase onto acrylic carriers were studied. The activity of immobilized enzyme preparations was also studied over a range of pH values and temperatures and thermal and pH stabilities were determined. The use of the immobilized preparation for penicillin G hydrolysis in a batch reactor was investigated. The immobilized enzyme gave a significant reduction in hydrolysis time compared to hydrolysis by the native enzyme. 相似文献
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Munish Puri Harsimran Kaur John F Kennedy 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2005,80(10):1160-1165
Naringinase (EC 3.2.1.40) from Penicillium sp was immobilized by covalent binding to woodchips to improve its catalytic activity. The immobilization of naringinase on glutaraldehyde‐coated woodchips (600 mg woodchips, 10 U naringinase, 45 °C, pH 4.0 and 12h) through 1% glutaraldehyde cross‐linking was optimized. The pH–activity curve of the immobilized enzyme shifted toward a lower pH compared with that of the soluble enzyme. The immobilization caused a marked increase in thermal stability of the enzyme. The immobilized naringinase was stable during storage at 4 °C. No loss of activity was observed when the immobilized enzyme was used for seven consecutive cycles of operations. The efficiency of immobilization was 120%, while soluble naringinase afforded 82% efficacy for the hydrolysis of standard naringin under optimal conditions. Its applicability for debittering kinnow mandarin juice afforded 76% debittering efficiency. Copyright © 2005 Society of Chemical Industry 相似文献
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采用共价交联的方法将β-葡萄糖苷酶固定到球形壳聚糖上,并对固定化酶的性质进行表征,得出固定化酶的最佳反应条件:pH=5,温度40℃。据此用乙酸乙酯和pH=5缓冲溶液的双相体系,在40℃条件下水解大豆异黄酮。与游离酶相比,固定化酶在此双相体系中起到了稳定酶的作用;与单相体系相比,双相体系中产物的产率显著提高,反应速率也更快,且能有效去除粗品大豆异黄酮的异味。对于30%左右级别的大豆异黄酮,水解的两个主要水解产物(大豆苷元和染料木素)的产率都能达到70%。 相似文献
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明胶膜固定化脲酶的制备及性质 总被引:7,自引:0,他引:7
以明胶为载体,戊二醛为交联剂,采用包埋-交联联用法制备了明胶膜固定化脲酶,其酶活力为6 07U/g载体,酶活力收率为66 1%。最优固定化条件是包酶量为10mg酶/g明胶,ρ(明胶)=100g/L,φ(戊二醛)=0 5%。研究了固定化酶的性质,并与游离酶作了比较,游离酶的最适pH=7 0,固定化酶的最适pH=6 5;游离酶的最适温度为60℃,固定化酶的最适温度升至70℃;固定化酶与游离酶的米氏常数Km分别为11 7mM和12 4mM;固定化酶在80℃下180min仍保留初始活力的10%,而游离酶几乎完全失活。固定化酶重复使用20次其活力仅下降15%,4℃下贮存35d后仍保持初始活力的55%。 相似文献
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Immobilization of a thermostable inorganic pyrophosphatase from the archaeon Pyrococcus furiosus onto amino‐functionalized silica beads
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This study focuses on the preparation and application of a recombinant thermophilic inorganic pyrophosphatase from the archaeon Pyrococcus furiosus on amino‐functionalized silica beads. The amino‐functionalized silica beads were prepared by coating with 3‐aminopropyltriethoxysilane by silanization. The thermostable inorganic pyrophosphatase was rapidly and successfully immobilized onto the amino‐functionalized silica beads with glutaraldehyde as a coupling agent (within 12 min, >95.4% protein was immobilized onto the support). The results show that the protein could be immobilized efficiently, with up to 1 mg of protein/g of support with 92.9% activity. Compared with the free enzyme, the immobilized enzyme displayed a high activity toward inorganic pyrophosphate, less sensitivity toward the pH, and increased thermal stability. The immobilized enzyme retained 56.9% of its initial activity after hydrolysis of the inorganic pyrophosphate after 12 consecutive cycles (total = 330 min) at high temperature; this indicated a high protein stability suitable for practical applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40700. 相似文献
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银/二氧化硅复合载体固定木瓜蛋白酶的研究 总被引:2,自引:0,他引:2
以沉积了银纳米粒子的二氧化硅微球为载体,戊二醛为交联剂共价固定了木瓜蛋白酶。研究了戊二醛用量以及载体中银纳米粒子质量分数对酶负载率、相对活力和酶活回收率的影响,考察了温度和pH值对固定酶的影响。结果表明,戊二醛的适宜质量分数为5%;当载体的银负载量(质量分数)为0.68%时,固定木瓜蛋白酶活回收率最高,比使用未负载银载体提高了131%;固定酶的最适反应温度为75℃,与游离酶基本相同;最适pH值为7.5,与游离酶相比向碱性方向移动了1个单位。 相似文献
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海藻酸钠-明胶协同固定化S-腺苷甲硫氨酸合成酶的研究 总被引:1,自引:0,他引:1
以海藻酸钠和明胶为载体,对S-腺苷甲硫氨酸合成酶进行固定化。再用戊二醛对其进一步交联,增强固定化酶的稳定性。考察了海藻酸钠和明胶质量分数、CaCl2质量分数、酶和载体比例以及交联剂戊二醛体积分数等因素对固定化酶的影响。结果表明,最佳固定化条件为:海藻酸钠质量分数2.0%、明胶质量分数1.0%、CaCl2质量分数4.0%、固定化酶量为2.5 g/L凝胶、戊二醛体积分数0.6%。交联固定化酶热稳定性得到大幅度提高,在50℃下保温5 h仍保留72%的活力,而游离酶则完全失活。交联固定化酶在碱性溶液中的稳定性较高,在pH=8.0~9.0的缓冲液中4℃保温10 h酶活性仍保留87%以上。将交联固定化酶用于S-腺苷甲硫氨酸的合成,连续反应8批次后酶活性仍保留65%。 相似文献
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《Reactive and Functional Polymers》2012,72(11):839-845
Poly(vinyl alcohol-co-ethylene) (PVA-co-PE) nanofibrous membranes were successfully fabricated and activated with glutaraldehyde (GA) to interact with enzyme molecules. A lipase isolated from Candida rugosa was employed as a model biocatalyst and successfully immobilized onto the membrane surfaces via covalent bonds with the aldehyde groups. Scanning electron microscopy images revealed that the membranes retained uniform nanofibrous and open porous structures after the treatments. The results indicated that the increment of the initial glutaraldehyde concentration induced an increase of the enzyme loading on the membrane surfaces but a decrease in the activity of the immobilized enzyme. Under an optimum condition, the glutaraldehyde activated PVA-co-PE nanofibrous membrane reached the highest enzyme activity at 676.19 U/g of the membrane. The pH tolerance, thermal and storage stability of the immobilized lipase were significantly improved. In addition, the immobilized lipase can be easily recovered and retained at 67% of its initial activity after 10 time uses. Therefore, the glutaraldehyde activated PVA-co-PE nanofibrous membrane is a promising solid support media for enzyme immobilization, and the immobilized enzymes could have broad biocatalytic applications. 相似文献
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Usually immobilization is a requirement for the use of enzymes as an industrial biocatalyst. In this work, endophytic fungus Cercospora kikuchii lipase was immobilized by covalent binding on agricultural by-products and microcrystalline cellulose. The enzyme support system was submitted to spouted bed drying. Lipase immobilized on microcrystalline cellulose with 1.5% of glutaraldehyde showed the best results, presenting 179.1% of the original activity after drying, followed by rice husk (173.9%), corn stover (169.8%), sugarcane bagasse (157.3%), green coconut fiber (102.3%), and corncob (99.8%). The immobilized derivatives obtained showed a decreased enzyme activity with an average of only 17.31%, whereas the enzyme in its free form lost 85.8% of its initial activity after storage for 6 months. The operational stability showed that the biocatalysts prepared retained an average of 67.2% of the initial activity after five reuse cycles. The results showed that the use of agricultural by-products as low-cost support material associated with the spouted bed drying is promising and can contribute to industrial application of biocatalysts. 相似文献