Trichoderma reesei engineering bacterium as well as preparation method and application thereof

Abstract

The invention discloses trichoderma reesei engineering bacterium as well as a preparation method and an application thereof. The trichoderma reesei engineering bacterium disclosed by the invention canbe used for efficiently expressing endoglucanase; under optimized conditions, the extracellular enzyme activity of endoglucanase expressed by the trichoderma reesei engineering bacterium reaches 31.46 U/mL, which is 7.6 times of the enzyme activity of endoglucanase expressed by wild bacteria and 2.3 times of the enzyme activity expressed by escherichia coli; the endoglucanase expressed by trichoderma reesei has higher tolerance to SDS, especially in 0.5% SDS, the residual enzyme activity of tEgh31 enzyme is close to 55%, and the residual enzyme activity of rEgh31 expressed by prokaryote is about 30%; and the specific activity (161.2 U/mg) of the tEgh31 enzyme expressed by trichoderma reesei is improved by about 19% compared with the specific activity (135.7 U/mg) of the rEgh31 enzyme expressed by prokaryote. Therefore, the endoglucanase expressed by fungi has a relatively wide application prospect.

Description

technical field [0001] The invention belongs to the field of biotechnology, and in particular relates to a Trichoderma reesei engineering bacterium and a preparation method and application thereof. Background technique [0002] There are differences between enzymes produced by eukaryotes and enzymes produced by prokaryotes in terms of optimum pH, optimum temperature and other reaction conditions and catalytic mechanisms. Trichoderma reesei is a filamentous fungus and is a multicellular eukaryotic microorganism. The Trichoderma reesei expression system has the advantages of high expression level, secreted expression, and high-density fermentation, and is currently widely used in the industrial production of enzymes. [0003] According to the different functions of the promoter, the expression system of Trichoderma reesei can be divided into constitutive expression system and inducible expression system (Gao Yun, 2002). Constitutive promoters often correspond to genes necess...

AI Technical Summary

Problems solved by technology

[0004] Trichoderma reesei mainly produces acid cellulase. Neutral and alkaline cellulase derived from bacteria are difficult to express efficiently in Trichoderma reesei expression system due to pH adaptability. At present, the endoglucanase is in There are very few reports on constitutive expression in Trichoderma reesei, and how to use the strong promoter Ppdc to realize the constitutive expression of bacterial endoglucanase Egh31 in Trichoderma reesei is an urgent problem to be solved

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