Immobilization method using chitosan as carrier

Abstract

The invention discloses an immobilization method using chitosan as a carrier, which comprises the following steps of: directly mixing and crosslinking a chitosan solution with a solution or suspension of enzyme, cells, thallus, fermentation liquor or protein, and other substances to be immobilized; and immobilizing and dispersing under the alkaline condition to obtain granular crosslinking chitosan. An immobilized particle formed by the invention has the advantages of porous structure, high mechanical strength, high filter performance and no need of complex equipment. The invention can be used for large-scale cell immobilization, enzyme immobilization and direct immobilization of fermentation liquor without solid-liquid separation, such as 2,000L scale fermentation liquor direct immobilization in citrulline production and conversion reaction for preparing S-2,2-dimethylcyclopropylformamide, R-flurbiprofen, N-acetylneuraminic acid or R-3-hydroxyl-diethyl glutarate. The invention can be also used for the degerming or clarifying of a solution.

Description

technical field [0001] The invention relates to an immobilization method using chitosan as a carrier, in particular to an immobilization method for enzyme, cell, bacterium, fermentation liquid or protein. Background technique [0002] Immobilization is relative to free enzyme or cells. The target substance is bound in the carrier region by chemical or physical means, while maintaining catalytic activity and can be used repeatedly. After immobilization, enzymes or cells move with the carrier, so in scientific research and production, people can control the behavior of invisible enzymes and cells by manipulating the solid carrier visible to the naked eye. [0003] Immobilization methods mainly include adsorption method, embedding method and cross-linking method. The key factors that determine whether the immobilization process has actual economic value are the price and performance of the carrier. Sodium alginate, carrageenan and chitosan are the most researched carriers, w...

AI Technical Summary

Problems solved by technology

The first drawback is that granulation technology is often extrusion molding, which is very difficult to achieve large-scale operation, and the particle size is extremely difficult to control

The second defect is that the particles formed by the above-mentioned conventional process have poor mechanical properties and are difficult to withstand continuous mechanical agitation. Certain flow properties are required for application

The third defect is that the conventional method of immobilizing the fermentation broth must first collect the bacteria to obtain the bacteria, and it is difficult to filter the fermentation broth of many microorganisms. It is not the first choice for industrialization to collect the bacteria by large-scale centrifugation. Therefore, the industry has to adopt other methods such as ceramic membranes. means instead of immobilization

The above methods all granulate chitosan first, and then cross-link or adsorb and fix the target product after treatment, which also includes the method of wrapping chitosan on the surface of magnetic particles, but this method is difficult to scale up and costs more High, less adsorption capacity

The above methods all have the disadvantages of non-uniform cross-linking degree and non-uniform strength of immobilized particles.

When the above method is applied to the immobilization of fermentation broth, it is necessary to separate the solid and liquid of the fermentation broth, collect the bacteria and then carry out the immobilization operation. The effect of solid-liquid separation is highly dependent on the equipment.