Trichoderma reesei mutant strain for highly yielding neutral cellulase

Abstract

The invention relates to the technical field of an enzyme preparation, and particularly relates to a trichoderma reesei mutant strain and application thereof. After the mutant strain is subjected to shake-flask fermentation for 5 days, the enzyme activity of the neutral cellulase in fermentation supernatant fluid is 114m / ml, and is improved by 34 percent through being compared with that of an original strain; in the 20L fermentation tank small tests, the enzyme activity of the neutral cellulase in the fermentation supernatant fluid reaches 1335 u / ml; the amplification effect is obvious on theexpression quantity after the comparison with a shake-flask result; and the mutant strain has the advantages of thick and short mycelia, high dissolved oxygen level, low fermentation liquid viscosityand the like in the fermentation process; and the unexpected technical effects are achieved. The trichoderma reesei mutant strain can be widely applied to cellulase production, so that the productioncost of the cellulase can be favorably reduced; and the popularization and the application of the cellulase in relevant fields can be promoted.

Description

technical field [0001] The invention belongs to the technical field of microbial screening, and specifically relates to a mutant strain of Trichoderma reesei with high production of neutral cellulase and its application. technical background [0002] Cellulase is a general term for a group of enzymes that can degrade cellulose and finally generate glucose. It is not a simple enzyme, but a multi-component enzyme system that acts synergistically in the process of degrading cellulose. A class of glycoside hydrolases that hydrolyze β-1,4-glycosidic bonds. According to the optimal pH value of enzyme activity, cellulase can be divided into acid cellulase, alkaline cellulase and neutral cellulase. [0003] The cellulase whose optimum pH is between 6.0-8.0 is called neutral cellulase, which is also a multi-component enzyme system, but the ratio and composition of various enzymes have their particularity. Because the earliest researched cellulase-producing microorganisms were mainl...

AI Technical Summary

Problems solved by technology

Although the fungi producing neutral cellulase have strong enzyme production ability, the fermentation time is often very long, which affects the production intensity and efficiency; and in industry, most filamentous fungi produce enzymes by solid fermentation, which is not conducive to submerged liquid fermentation; For eukaryotes, enzyme-producing genes contain introns, and the enzymes produced often need to be induced, which brings inconvenience to the construction of genetically engineered bacteria

[0006] Cellulase derived from bacteria are mostly neutral or alkaline enzymes, most of the neutral cellulase produced by aerobic bacteria are extracellular enzymes, and those produced by anaerobic bacteria are often adsorbed on the cell wall in the form of cellulite. Bacterial enzymes do not need to be induced, and bacteria are convenient for liquid fermentation and the fermentation cycle is short. Enzyme-producing genes are more suitable for the construction of genetically engineered bacteria, but the enzymes produced by bacteria have low enzyme activity