纤维素在固定化酶的研究进展

分析了酶及固定化酶研究进展及工业化应用瓶颈,并对无机载体、合成聚合物载体、天然聚合物载体等当前酶固定化载体材料和种类及其特点进行总结,重点介绍了纤维素作为一种无毒、可再生、可降解、生物相容性好的天然高分子材料用于固定酶载体的研究进展,阐述了纤维素在固定化酶技术工业应用亟需解决的问题及未来的发展趋势。     

青霉素酰化酶固定化载体材料研究进展

就青霉素酰化酶固定化载体材料的研究和应用进行了论述。重点介绍了功能基化高分子聚合物、含环氧基高分子聚合物、离子型层状水滑石和介孔分子筛等新型载体的结构特性和对青霉素酰化酶的固定化作用,并对近年来固定化生物酶载体材料的发展动向和趋势加以评述和展望。     

载体固定化酶的应用及前景展望

载体固定化酶可以提高酶的稳定性,并可大大提高回收利用率。固定化酶的载体从传统类型向新型发展,传统类型主要是天然高分子产物,新型载体主要包括人工合成高分子材料、无机新型材料、智能型载体等。载体可通过化学或物理方法固定到酶上,化学方法主要是共价键结合法和交联法;物理方法包括吸附法、包埋法、热处理法。载体固定化酶在生物医学、食品行业、环境工程中具有广泛的应用前景,其发展将和互联网、大数据联系起来。     

酶固定化研究进展

从吸附法、交联法、共价结合法、包埋法四个方面介绍了固定化酶的研究进展情况,并对改性载体--磁性高分子微球的研究情况作了总结.指出今后研究的主要方向是对天然高分子载体进行改性,开发新型、高效的固定化酶技术.     

吸附法固定化酶的研究进展

酶的固定化是生物技术中最为活跃的研究领域之一。吸附法固定化载体选择范围较广,价格低廉,固定化操作过程简单,在经济上是最具吸引力的固定化方法。综合性能优良的载体材料的设计与制备是固定化酶技术领域的一个非常重要的研究内容。介绍了吸附法固定化酶的独特优势,对近年来国内外有关吸附固定化酶新型载体材料、载体材料的改性以及固定化方法的研究现状进行了简要的综述,并对吸附法固定化酶产业化技术瓶颈及发展趋势进行了总结。     

酶固定化研究进展

从吸附法、交联法、共价结合法、包埋法四个方面介绍了固定化酶的研究进展情况，并对改性载体——磁性高分子微球的研究情况作了总结。指出今后研究的主要方向是对天然高分子载体进行改性，开发新型、高效的固定化酶技术。     

脂肪酶的固定化及其手性拆分的研究进展

将脂肪酶固定化可提高酶的选择性、稳定性等,已广泛应用于手性拆分等研究。常用的高分子固定化载体有聚丙烯酸多孔树脂及带功能基团的共聚物等。从脂肪酶结构的角度介绍其手性拆分机理,并具体讨论了一些商品化固定化脂肪酶在手性拆分中的应用及固定化载体材料对手性拆分的影响。     

酶固定化载体及固定化方法最新研究进展

游离酶在工业生产等实际应用中存在着性质较不稳定、耐酸碱性弱、耐热性不强等诸多的局限性,对游离酶进行固定化是克服上述的不足的有效手段。本文将对常见的固定化载体(有机载体材料、无机载体材料和复合载体材料)和固定化方法(吸附法、包埋法、离子结合法、交联法和热处理法)以及一些新型固定化方法和新载体研究进展进行系统的深入介绍,并归纳和总结它们各自的特点。最后介绍了当前酶固定化载体材料和固定化方法的研究重点,以及阐述了固定化酶技术未来的趋势—运用复合载体材料和多种方法联用的固定化技术。     

纳米结构酶催化剂研究进展

将酶负载于载体上可以提高工业应用中酶的稳定性并便于重复使用。纳米材料的发展为固定化酶提供了新的契机,利用纳米材料固定化酶有望进一步提高酶在工业环境中的催化性能、拓展固定化酶的应用范围。本文主要关注近年来在纳米结构酶催化剂方面的研究进展,重点介绍本研究组以无机晶体、金属有机骨架材料、石墨烯和功能高分子等为载体进行酶固定化以及酶催化过程多尺度分子模拟方法的研究进展,讨论了纳米结构酶催化剂的发展前景。     

PAM/HEMA固定化α-胰凝乳蛋白酶的研究

基于人工合成高分子载体材料的固定化酶是目前国际上的研究热点,而国内尚未进行较为深入的研究。本文以聚丙烯酰胺／甲基丙烯酸-α-羟基乙酯为基质来固定α-胰凝乳蛋白酶,并对所制备的固定化酶的性能进行了多方面的研究,然后通过一系列实验测定其相应的活性,为进一步的研究提供了必要的实验依据。     

氨基功能载体固定化酶研究进展

综述了甲壳素、壳聚糖天然氨基功能载体和氨基化硅胶化学合成载体的制备方法,并介绍了利用戊二醛直接固定、载体活化和酶活化固定化酶的方法,最后对氨基功能载体固定化酶的发展趋势加以评述:在利用氨基功能载体固定化酶过程中,有必要有针对性地合成一些新的氨基功能载体,使其反应条件更温和、酶的固载量更大、酶活力回收率更高、稳定性更强。或者针对特定的载体和酶,通过结合配体、添加稳定剂、固定前修饰、固定后修饰和后固定化技术处理等方法,进一步改善固定化酶的性能。     

多孔半互穿温敏水凝胶点击反应固定化酶

以N-异丙基丙烯酰胺（NIPAM）为温敏单体,引入线性聚甲基丙烯酸-β-羟乙酯（PHEMA）或乙二胺胺化的聚甲基丙烯酸-β-羟乙酯（PAEMA）,制备多孔半互穿水凝胶,并引入马来酰亚胺基团修饰,制备了两种新型水凝胶酶固定化载体Ⅰ和Ⅱ,凝胶的平均孔洞大小均约在10 ?m以上。以Ⅰ和Ⅱ为载体,马来酰亚胺与巯基的点击反应为基础,进行脂肪酶与糖化酶的固定化研究。结果表明,通过点击反应固定化得到的固定化脂肪酶最高活力回收率达6.03%,是相同条件下戊二醛固定化的5倍左右,且稳定性较高。     

Behavior of immobilized glucose oxidase on membranes from polyacrylonitrile and copolymer of methylmethacrylate‐dichlorophenylmaleimide

Two new ultrafiltration membranes were obtained from a polymer mixture, containing 60% polyacrylonitrile (PAN) and 40% copolymer of methylmethacrylate‐dichlorophenylmaleimide (MMA‐DCPMI). Membrane 1 (MB1) contains 40% DCPMI of the copolymer, and membrane 2 (MB2) contains 15% of the copolymer. The pore size, the specific surface, the water content, the water flux, and the selectivity were determined for the two membranes. The presence of dichlorophenylmaleimide in the copolymer ensures the preparation of membranes suitable for direct covalent enzyme immobilization without further modifications. These membranes were used for immobilization of glucose oxidase (GOD). High amount of bound protein was found on each of the membranes. High relative activities of the immobilized GOD were achieved, 72% for MB1 and 68% for MB2. The properties of the immobilized enzyme (GOD) were determined: optimum pH and temperature and pH, thermal, and storage stability, and then compared with the properties of the native enzyme. The kinetic parameters of the enzyme reaction, Michaelis constant (K_m) and maximum reaction rate (V_max), were also investigated. The results obtained showed that the ultrafiltration membranes prepared from the mixture of PAN and the copolymer MMA‐DCPMI were suitable for use as carriers for the immobilization of GOD. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4334–4340, 2006     

酶定向固定化方法及应用的研究进展

传统固定化方法常会导致酶活性大幅度下降,回收率较低,而酶定向固定由于固定化后可完全暴露其活性部位,因而可以保持较高的酶活回收率。本文主要综述了定向固定化酶的两种方法,分别为共价定向固定和非共价定向固定。其中非共价定向固定化主要是抗体与抗原、亲和素/链霉亲和素和生物素以及组氨酸标签与Co2+/Ni2+之间的亲和作用;共价定向固定化主要是通过半胱氨酸残基上的巯基与载体作用。简述了其在生物传感器、分子识别、酶生物燃料电池及酶纯化方面的应用。最后指出今后的主要研究方向为探索新的定向固定化标签以降低对酶活性部位的影响,应用新的载体以提高固定化酶酶活回收率,优化固定化过程及简化固定化步骤等。     

固定化酶研究进展

固定化酶有许多优点,尤其是稳定性和可重复使用性使其在许多领域得到广泛应用.固定化酶技术是一门交叉学科技术,目前已得到长足的发展.介绍了固定化酶制备的传统方法以及一些新方法,同时对酶在一些性能优良的载体上的固定进行了综述.     

A novel electron beam-based method for the immobilization of trypsin on poly(ethersulfone) and poly(vinylidene fluoride) membranes

A novel technique for the covalent immobilization of trypsin in a one-step reaction using low-energy electron beam is described. The enzyme immobilization was applied on poly(ethersulfone) and poly(vinylidene fluoride) microfiltration membranes. For this purpose, the membranes were dipped in an aqueous solution of trypsin followed by electron beam treatment.The effect of irradiation conditions on the immobilization was investigated, as well as the resulting membrane properties with respect to enzymatic activity, immobilized enzyme concentration, pure water flux, scanning electron microscopy, and porosimetry. This technique shall provide a simple, inexpensive method for enzyme immobilization on various polymer membranes and offer a tool for the application in enzymatic membrane reactors.     

Reaktive polymere Träger für die Immobilisierung von Enzymen

Reactive and hydrophilic carriers with macroreticular structure and with excellent mechanical stability were synthesized by copolymerization of 4-isothiocyanato styrene and acrylic acid with different amounts of 1,4-divinylbenzene as crosslinking agent in the presence of petroleum ether. The porosity and the swellability of the carriers was investigated. The binding ability for trypsin was determined in dependence of the composition and of the grain size of the carriers and as a function of the offered amount of the enzyme during the immobilization. For the immobilized enzyme the pH/activity-profiles and the effectiveness were determined and the effects of buffers were investigated.     

Immobilization of cellulase using porous polymer matrix

A new method is discussed for the immobilization of cellulase using porous polymer matrices, which were obtained by radiation polymerization of hydrophilic monomers. In this method, the immobilized enzyme matrix was prepared by enzyme absorbtion in the porous polymer matrix and drying treatment. The enzyme activity of the immobilized enzyme matrix varied with monomer concentration, cooling rate of the monomer solution, and hydrophilicity of the polymer matrix, taking the change of the nature of the porous structure in the polymer matrix. The leakage of the enzymes from the polymer matrix was not observed in the repeated batch enzyme reactions.     

Immobilization of Trametes versicolor laccase on different PGMA‐based polymeric microspheres using response surface methodology: Optimization of conditions

Enzymatic immobilization is a versatile alternative to improve enzyme stability and enable its reuse. In this study, the change in the immobilized enzyme properties due to the type of functional group on the carrier was evaluated. For that, monodisperse polymeric microspheres with two functional groups widely used in laccase immobilization—oxirane [poly(glycidyl methacrylate) (PGMA)] and hydrazide—were synthesized by dispersion polymerization to covalently immobilize the laccase Trametes versicolor. Using a response surface methodology, laccase immobilization was optimized for each microsphere type. As a result, laccase immobilization on PGMA carriers appears to broaden the pH and temperature ranges, storage stability, and reusability compared to free and hydrazide enzymes. These aforementioned characteristics indicate that PGMA microspheres could act as an ideal support for enzyme immobilization in biotechnological applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45249.     

Immobilization of papain on crosslinked polymer supports: Role of the macromolecular matrix on enzymic activity

Papain was immobilized on polymer supports with spacer arms of varying nature and length. As the length of the spacer arm increased, there was a marked increase in the extent of enzyme immobilization and activity of immobilized enzymes. When a long, flexible and hydrophilic polyethylene glycol spacer was introduced between the polystyrene backbone and the functional group used for immobilization, the extent of coupling and enzyme activity increased. Dependence of enzyme activity on the nature and extent of crosslinking and on the nature of the polymeric backbone was investigated. Hydrophilic polyacrylamide-based supports were found to be more efficient supports for immobilization compared to hydrophobic polystyrene-based supports.