Enzymes immobilization technology

Enzymatic reactions are commonly observed or practiced in various kinds of food and biotechnology products. With the goals of reducing operating costs and improving product quality, a number of enzyme immobilization techniques have been developed in recent decades [Woodward, 1985]. The availability of robust membranes, particularly porous inorganic membranes, has improved the enzyme immobilization technology. One type of membrane bioieactors immobilizes enzyme in the membrane pores by dead-end filtration of the enzyme solution. 

Although tyrosinase has widespread applications, its use is limited by its inherent instability and rapid inactivation. By using enzyme immobilization technology, good operational stability and long-term stability can be achieved for tyrosinase. 

Miyahara Y., Manizumi T., Shiokawa S., Matsuoka H., Karube I. and Suzuki S. (1983) Micro urea sensor using semiconductor and enzyme immobilizing technologies. Chem. Soc. Japan, 6, 823-830. 

Porous polymer materials, especially in particulate form, are of interest in a diverse range of applications, including controlled drug delivery, enzyme immobilization, molecular separation technology, and as hosts for chemical synthesis [101-104]. MS materials have been used as hosts for the template synthesis of nanoporous polymer replicas through in situ polymerization of monomers in the mesopores [105-108]. 

Sol-gel technology has also been applied to enzyme immobilization. The preparation of the matrix that usually show a good mass transport, is carried out under relatively mild experimental conditions, so the integrity of the biomolecule is preserved. 

The recent literature in bioelectrochemical technology, covering primarily the electrochemical aspects of enzyme immobilization and mediation, includes few reports describing engineering aspects of enzymatic biofuel cells or related devices. Current engineering efforts address issues of catalytic rate and stability by seeking improved kinetic and thermodynamic properties in modified enzymes or synthesized enzyme mimics. Equally important is the development of materials and electrode structures that fully maximize the reaction rates of known biocatalysts within a stable environment. Ultimately, the performance of biocatalysts can be assessed only by their implementation in practical devices. 

Several choices must be considered when choosing an immobilization technology. They are remarkably similar to the choices made when choosing a scaffold for cell growth. The immobilization should take place on a material that is strong and tough, has a porous structure, high surface area, permeability, mass transport, and space for biomass buildup. The material should be hydrophilic and inert but have the ability to bind enzymes. It should be hydrolytically stable and be able to resist the environment in which it will have to operate it cannot be toxic to the enzyme. 

One of the approaches has been to genetically design fusion proteins with an affinity domain linked to the enzyme. This technology provides for one-step purification as opposed to the multistep processes required for purification of commercial enzymes. Furthermore, immobilization can be achieved at the same time, leading to a minimization of bioreactor preparation costs. Fusion proteins with streptavidin as an affinity domain have been designed (Sano and Cantor, 1991 Walsh and Swaisgood, 1994 Lee and Swaisgood, 1998). 

Immobilization technology makes it possible to reuse enzymes and to restrict them to certain areas of a reaaion system. For example, in a flowing system, the product stream is not contaminated with enzymes and the reactions are run in a defined volume element of the total reaction volume. 

Enzyme Immobilization Zaborsky, O. R., Immobilized Enzymes, CRC Press, 1973. Lee, Y Y and G. T. Tsao, Engineering Problems of Immobilized Enzymes, J. Food Technol., 39, 667 (1974). Messing, R. A., Immobilized Enzymes for Industrial Reactors, Academic Press, 1975. Torry, S., Enzyme Technology, Noyes Data Corp., Park Ridge, New Jersey, 1983. 

Enzyme immobilization is considered as an important factor in biosensor technologies. Great attempts are in progress for finding novel materials for fabrication electrochemical biosensors. Due to electrical, optical, biocompatible properties, structure stability and small... 

Xie T, Wang A, Huang L et al (2009) Recent advances in the support and technology used in enzyme immobilization. Afr J Biotechnol 8 4724 733... 

Vacuum evaporation is cheap and enables the creation of multiple sensors on small surfaces. It provides therefore a good alternative to ISFET technology in biosensors. Another advantage is the possibility of using established methods for enzyme immobilization. 

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