Immobilization of enzymes on alginic acid-polyacrylamide copolymers (original) (raw)
Enzyme immobilization on graft copolymers
1999
Immobilised enzymes can be reused, easily separated from the reaction medium, and are more stable in most of the cases. Despite of these advantages, there are still some problems facing the usage of the immobilised enzyme in industry. One of those problems is diffusion-limitation of both the reactants and the products. This problem becomes even more serious when the products are inhibitors of the enzymes. Different strategies for overcoming this problem have been discussed in this thesis. A new solution to overcome diffusion limitation is based on processing the enzymatic reaction under non-isothermal conditions. In such a bioreactor the enzymes have to be immobilised on a hydrophobic membrane. In this thesis, two enzymes,β-galactosidase and penicillin G acylase have been immobilised onto teflon and nylon membranes. Two grafting techniques have been used to modify the membranes in order to be able to bind the enzyme. These grafting techniques were based on using high-energy radiatio...
Polymer-Based Strategies for Enzyme Immobilization: A Comprehensive Review
Tuijin Jishu/Journal of Propulsion Technology, 2023
Enzyme immobilization refers to the process of attaching or confining enzymes onto a solid support or within a matrix, often made of polymers or other materials. This immobilization creates a stable and controlled environment for the enzyme to interact with substrates and perform catalysis. The primary goal of enzyme immobilization is to enhance enzyme stability, reusability, and activity under specific conditions, making them more practical and efficient for various biotechnological, industrial, and medical applications. Immobilization methods can vary widely, including physical adsorption, covalent bonding, entrapment within matrices, encapsulation, crosslinking, and more. These methods provide a means to control the interactions between the enzyme and the surrounding environment, affecting factors such as substrate accessibility, enzyme orientation, and stability. Due to their ease of fabrication and superior structural adaptability, polymer compounds in a variety of physical forms, including beads, films, fibers,and coatings,have become popular as supportive materials for enzyme immobilization. For enzyme immobilization, a number of natural polymers, including agar, agarose, alginate, dextran, chitosan,and carrageenan, as well as synthetic polymers, such as polyamides, polystyrene, and polyacrylamide, are often employed as a carrier system. The immobilization offers a cost-effective system for various applications in biotechnology, industry, and research.
Biotechnology and Bioengineering, 1980
A method.of enzyme immobilization by graft copolymerization on polysaccharides is reported. Glycidylmethacrylate was used as a vinylating reagent and the reaction product with enzymes (HRP, GOD, Am, ChT) was copolymerized with different matrices (cellulose, Sepharose, Sephadex, starch). Various factors affect the final activity of copolymers; these include the redox system, the type of support, and the quantity and type of vinyl monomer added. Using a fixed quantity of enzyme and support (3 mg enzyme, 100 mg support), the coupling efficiency varied from 2 to 50%. The most important characteristics in these immobilized systems were tested (stability in continuous washing, kinetic characteristics, storage, thermal, and lyophilization stability). Immobilized-enzyme graft copolymers have very similar kinetic behavior to that of the free enzyme. Diffusion is not seriously limited, as shown by kinetic parameters and energy activation values, and this indicates that the immobilization reaction does not alter the enzymatic activity.
Immobilization of Enzymes by Polymeric Materials
Catalysts
Enzymes are the highly efficient biocatalyst in modern biotechnological industries. Due to the fragile property exposed to the external stimulus, the application of enzymes is highly limited. The immobilized enzyme by polymer has become a research hotspot to empower enzymes with more extraordinary properties and broader usage. Compared with free enzyme, polymer immobilized enzymes improve thermal and operational stability in harsh environments, such as extreme pH, temperature and concentration. Furthermore, good reusability is also highly expected. The first part of this study reviews the three primary immobilization methods: physical adsorption, covalent binding and entrapment, with their advantages and drawbacks. The second part of this paper includes some polymer applications and their derivatives in the immobilization of enzymes.
Natural polymers: suitable carriers for enzyme immobilization
2021
Enzyme immobilization onto support carriers has the potential to overcome some of the limitations of soluble enzymes in practical applications. Various materials have been used as carriers, such as inorganic matrices, as well as natural and synthetic polymers. Production of carriers from natural biopolymers and their derivatives has been the focus of research worldwide, and a summary of their applications for enzyme immobilization is presented in this paper. Enzymes, or cells as an enzyme source, are entrapped inside a three-dimensional polymeric network, called a hydrogel, that is able to retain large amounts of water. This network can be formed by chemical cross-linking, ionotropic gelling in the presence of cation, or in thermo reverse polymerization, depending on the polymer in use and its physico-chemical characteristics. The most frequently used biopolymers as carriers for immobilization include alginate, cellulose, chitosan, collagen, xylan, pectin, and others.
ENZYME IMMOBILIZATION INTO POLYMERS AND COATINGS
In this study, we have developed strategies to immobilize enzymes into various polymer and coatings. Three categories of bioplastic matrices were investigated. The first type of bioplastics was prepared by irreversibly incorporating diisopropylfluorophosphatase (DFPase) into polyurethane (PU) foams. The resulting bioplastic retained up to 67 % of the activity for native enzyme. The thermostability of DFPase was highly affected by the immobilization process. Unlike native enzyme, immobilized DFPase had biphasic deactivation kinetics. Our data demonstrated that the initial rapid deactivation of immobilized DFPase lead to the formation of a hyper-stable and still active form of enzyme. Spectroscopic studies enabled a structural analysis of the hyper-stable intermediate.
Journal of Applied Polymer Science, 2005
Crosslinked polystyrene ethylene glycol acrylate resin (CLPSER) was developed for the immobilization of the enzyme catalase by the introduction of a crosslinker, O,OЈ-bis(2-acrylamidopropyl) poly(ethylene glycol) 1900 , to styrene. The crosslinker was prepared by the treatment of acryloyl chloride with O,OЈ-bis(2-aminopropyl) poly(ethylene glycol) 1900 in the presence of diisopropylethylamine. The resin was characterized with IR and 13 C-NMR spectroscopy. The catalytic activity of the catalase-immobilized system of CLPSER was compared with divinylbenzenecrosslinked polystyrene, ethylene glycol dimethacrylate crosslinked polystyrene, and 1,4-butanediol dimethacrylate crosslinked polystyrene systems. Crosslink levels of 2, 8, and 20 mol % were evaluated. Among these crosslinked systems, the 2 mol % system was found to be most suitable to support catalytic activity. When a long flexible hydrophilic poly(ethylene glycol) crosslink, introduced between the polystyrene (PS) backbone and functional groups was used for immobilization, the extent of coupling and enzyme activity increased. Depending on the nature of the support, the catalytic activity of the system varied. The hydrophilic CLPSER support was most efficient for immobilization compared to the other PS-based supports.
Effect of polymer support functionalization on enzyme immobilization and catalytic activity
Pure and Applied Chemistry, 2014
Two enzymes, laccase and peroxidase, were immobilized on chloromethylated styrene-divinylbenzene copolymers supports functionalized with phosphonates ((RO) 2 PO) or mixed ammonium and phosphonium groups (N + R 3 Cl-, P + Ph 3 Cl-). Phosphonates groups and quaternary ammonium salts were grafted on the "gel-type" copolymer by Michaelis-Becker polymer analogue reaction. Mixed polymer-supported ammonium and phosphonium salts were obtained by transquaternization of the ammonium groups to phosphonium group. The degrees of functionalization for obtained polymers were relatively high ensuring a sufficient concentration of active centers per unit mass of the copolymer. The obtained materials were characterized by thermal analysis, FTIR spectroscopy and SEM microscopy. The effects of OR1 and R2 radicals from phosphonate and respectively ammonium groups, as well as those of glutaraldehyde utilization on the immobilization yield and the catalytic properties of the supported enzymes were indicated. The activity of enzymes increased after immobilization and high immobilization yield was obtained for all the samples. The higher interaction of enzymes with support was indicated for mixed ammonium and phosphonium functions. A higher catalytic activity was obtained for peroxidase in oxidation of phenol and laccase in oxidation of anisole. The low effect of glutaraldehyde on enzyme activity reveals the strong interaction of enzyme with the polymer support, respectively with the functional groups.
Enzyme Immobilization: The Quest for Optimum Performance
Advanced Synthesis & Catalysis, 2007
Immobilization is often the key to optimizing the operational performance of an enzyme in industrial processes, particularly for use in non-aqueous media. Different methods for the immobilization of enzymes are critically reviewed. The methods are divided into three main categories, viz. (i) binding to a prefabricated support (carrier), (ii) entrapment in organic or inorganic polymer matrices, and (iii) cross-linking of enzyme molecules. Emphasis is placed on relatively recent developments, such as the use of novel supports, e.g., mesoporous silicas, hydrogels, and smart polymers, novel entrapment methods and cross-linked enzyme aggregates (CLEAs).