An engineering bacterium for producing immobilized alkaline pectinase nanospheres and its construction method and application

Abstract

The invention discloses an engineering bacterium and a construction method for producing alkaline pectinase immobilized nano micro-spheres by the aid of one-step processes, and belongs to the technical field of immobilized enzymes. A recombinant Escherichia coli strain E.coli BL21 lambda (DE3) pABC-PGL constructed by the aid of the gene recombination method is preserved in the General Biology Center of the China Committee for Culture Collection of Microorganisms, and a strain preservation number of the recombinant Escherichia coli strain is CGMCC NO.10911. The engineering bacterium and the construction method for producing the immobilized alkaline pectinase nano micro-spheres on the basis of the Escherichia coli strains have the advantages that alkaline pectinase genes which are currently industrially widely applied are fused at N tail ends of PHA (phytohemagglutinin) synthesis enzyme genes phaC by connecting peptides by the aid of the gene fusion method, recombinant gene segments are transformed into recombinant bacteria to be expressed in an inducible manner, nano micro-sphere complexes can be synthesized in the recombinant bacteria, alkaline pectinase is carried on the surfaces of the nano micro-sphere complexes and can be effectively combined with the surfaces of the nano micro-spheres to form immobilized alkaline pectinase, and alkaline pectinase immobilization production can be implemented at one step.

Description

technical field [0001] The invention belongs to the technical field of immobilized enzymes, and relates to a new method for producing immobilized alkaline pectinase in one step, in particular to an engineering bacterium used in one-step production of alkaline pectinase immobilized nano-microspheres and its Construction methods and applications. Background technique [0002] Alkaline pectinase generally refers to polygalacturonate lyase (E.C.4.2.2.2, polygalacturonatelyase, PGL), its optimum pH value is 8-10, and it can break the main chain of pectin polymer under high pH conditions. Produces unsaturated oligogalacturonic acid. The enzyme is an important emerging enzyme in the industrial field, and is widely used in inducing plant disease resistance, treating pectin wastewater, and fermenting coffee and tea. In recent years, studies have found that alkaline pectin lyase is an important enzyme for clean production. It is mainly used in pulp bleaching and textile biorefining ...

AI Technical Summary

Problems solved by technology

However, the traditional immobilization methods have their own advantages and disadvantages: ① Although the adsorption method has mild production conditions, is simple and low in cost, the enzyme is not firmly combined with the carrier and is easy to fall off.

② Covalent bonding method and cross-linking method Although the enzyme is firmly bound to the carrier and the enzyme is not easy to fall off, the reaction conditions are more intense, the enzyme is easily inactivated, and the production procedures are more cumbersome.

③ Although the embedding method is not affected by chemical reactions, immobilized enzymes with high activity can be produced, and the enzymes are not easy to fall off, but the enzymes are limited to a certain carrier, which makes the range of enzymes and substrates smaller, affecting Enzyme activity

[0006] At present, the one-step production of immobilized alkaline pectinase using this technology has not been reported.

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