Immobilized enzyme is a new technology developed in the 1960s. The so-called immobilized enzyme refers to an enzyme that has a catalytic effect in a certain space and can be used repeatedly and continuously. Enzyme-catalyzed reactions are usually carried out in aqueous solutions, while immobilized enzymes are treated with physical or chemical methods to make water-soluble enzymes insoluble in water and still have enzyme activity.
After the enzyme is immobilized, the stability generally increases, it is easy to separate from the reaction system, easy to control, and can be used repeatedly. It is convenient for transportation and storage, and is conducive to automated production, but the activity is reduced, the scope of use is reduced, and the technology has room for development. Immobilized enzyme is an enzyme application technology developed in the past ten years. It has attractive application prospects in industrial production, chemical analysis and medicine.
The research on immobilized enzymes began in 1910, and the formal research began in the 1960s. In the 1970s, it has been widely carried out all over the world.
Enzyme immobilization is a kind of technology that uses solid materials to confine or confine the enzyme to a certain area, and still carry out its unique catalytic reaction, and can be recycled and reused. Compared with free enzymes, immobilized enzymes overcome the shortcomings of free enzymes while maintaining their high efficiency, specificity and mild enzyme catalytic reaction characteristics. Immobilized enzymes are not only very active in the fields of chemistry, biology and bioengineering, medicine and life sciences, and have been rapidly developed and widely used, but also save resources and energy, reduce or prevent pollution.
The advantages and disadvantages of immobilized enzymes compared with water-soluble enzymes
Advantage:rn1) The immobilized enzyme can be used repeatedly, which improves the use efficiency of the enzyme and reduces the use cost.
2) The immobilized enzyme is easily separated from the reaction system, simplifies the purification process, and has high product yield and good quality.
3) In most cases, the stability of the enzyme is improved after immobilization.
4) The catalytic reaction process of the immobilized enzyme is easier to control.
5) The immobilized enzyme has a certain degree of mechanical strength and can act on the substrate solution by stirring or packing, which facilitates the continuous and automated operation of the enzyme-catalyzed reaction.
6) Compared with free enzymes, immobilized enzymes are more suitable for the use of multi-enzyme systems. Not only can the synergistic effect of the multi-enzyme system be used to greatly increase the rate of the enzyme catalytic reaction, but also the reaction can be controlled in a certain order.
Disadvantages: rn1) Immobilization may cause partial inactivation of enzymes and loss of enzyme activity.
2) Enzyme-catalyzed changes in the microenvironment may lead to changes in the reaction kinetics.
Application of immobilized enzyme
As one of the four components of biological engineering,
enzyme engineering has been widely used in food, medicine, textile and other sectors in industrial production. However, natural enzymes have low stability, are extremely sensitive to high temperature and organic solvents, are easily inactivated, and cannot be reused. They are mixed into the product after the reaction, making it difficult to purify the product. By using physical or chemical methods to immobilize the enzyme on the carrier, the resulting enzyme not only retains the original high activity and high selectivity of the enzyme, but also overcomes the shortcomings of the natural enzyme, and facilitates the continuity and automation of the reaction. Therefore, immobilized enzymes have become one of the main research contents in the field of modern enzyme engineering. The high stability of immobilized enzymes makes it have broad prospects in industrial production.
Food industry
Canned liquid tea beverages have rapidly developed into one of the mainstream products in the international beverage market since they were successfully developed in the 1980s. Aroma enhancement and demixing are two important factors restricting the development of tea beverages. Tannase and β-glucosidase were co-immobilized, and green tea, black tea, and oolong tea were used as examples to study the properties of co-immobilized enzymes. The results showed that after co-immobilized enzyme treatment, the total amount of essential oils of green tea, black tea and oolong tea all increased.
Fuel industry (biodiesel)
Biodiesel is mainly made with vegetable oil and animal oil as raw materials. Its main advantages are: biodegradability, renewable resources, non-toxic, low exhaust emissions, and it is an environmentally friendly fuel that can be used as a substitute for petroleum. The current production of biodiesel mainly uses chemical methods. This method has complicated process, high energy consumption, easy deterioration of products, and pollution in the production process. Therefore, some scholars have studied the use of biological enzymes, that is, the esterification of animal and vegetable oils and low-carbon alcohols through lipase to prepare corresponding fatty acid esters.
Pharmaceutical industry
Modern pharmaceuticals also mostly use chemical methods, but the chemical process is complicated, the raw materials are wasted seriously and pollution is prone to occur, so people gradually turn to the research of biological enzymatic pharmaceuticals and have obtained many gratifying results. For example, cephalosporins are gradually replacing penicillin as the main antibiotic in clinical applications.