High-efficiency endoglucanase rucelb, its coding gene, preparation method and application

Abstract

The invention belongs to the field of biological engineering, and relates to a novel endoglucanase RuCelB, a coded gene, a preparation method and an application thereof. The RuCelB contains a 25th-336th amino acid residue sequence of SEQ ID NO.2. The preparation method is as follows: obtaining positive cloning capable of hydrolyzing sodium carboxymethylcellulose by active screening rumen microorganism metagenomic cosmid library of a yak, and further obtaining a whole-length cds sequence of the RuCelB by building subcloning, sequencing and homologous comparison; and carrying out recombined expression and obtaining the RuCelB. The specific activity of the RuCelB taking the sodium carboxymethylcellulose as a substrate is up to 158.8U / mg, and the RuCelB also has the degradability for the substrates such as filter paper, cellotriose and the like. The RuCelB can be widely applied in degradation of cellulose, comprising the industries such as cellulose biotransformation, chemical engineering, textile, food, bioenergy, feedstuff adding, pharmaceutical Industry and the like.

Description

technical field [0001] The invention belongs to the field of bioengineering, and relates to an endoglucanase and a preparation method and application thereof. The invention also relates to the recombinant plasmid and recombinant genetically engineered strain of the endoglucanase. Background technique [0002] Cellulose is the most widely distributed and abundant renewable carbon source compound on earth. However, in the plant cell wall, the microfibrils formed by the aggregation of cellulose molecules are embedded in hemicellulose and lignin to form a network structure, which makes the cellulose not easy to degrade and thus difficult to be fully transformed and utilized. The hydrolysis of cellulose molecules requires the joint action of at least three cellulase enzymes, which are endo-glucanase (ie, endo-cellulase), exo-glucanase (also known as exo-cellulose enzyme, cellobiohydrolase) and β-glucosidase. Endo-glucanase can randomly cut β-1.4-glucosidic bonds in the amorpho...

AI Technical Summary

Problems solved by technology

Although endocellulase is very important in degrading cellulose, its enzyme activity is often relatively low relative to its role, and soluble substrates are commonly used to screen and evaluate enzyme activity, but using soluble The specific activity data measured by the substrate cannot really represent the activity when hydrolyzing lignocellulose, because the endocellulase that is really active on insoluble substrates, especially crystalline insoluble substrates, is relatively small, and the insoluble substrates The enzymatic activity of the endocellulase is often very low even if it exists. The contradiction between this cloning strategy and the actual application requirements has caused most of the endocellulase to have little practical application value.

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