A method for improving the cellulose degradation ability of thermophilic myceliophthora and an engineered strain

Abstract

The present invention relates to the field of agricultural biotechnology, and in particular to a method for improving the cellulose degradation ability of thermophilic myceliophthora and an engineered strain. The method comprises the steps of overexpressing a homologous gene encoding a lytic polysaccharide monooxygenase and a gene encoding a β-glucosidase in thermophilic myceliophthora. alp 1‑ Mtlpmo‑Mtbgl The ability of degrading microcrystalline cellulose was significantly higher than that of the starting bacteria, and the total production of cellooligosaccharides increased by 68.53%, the total production of cellooligosaccharide acid increased by 189.08%, and the glucose production increased by 254.14%; the engineered bacteria Δ alp 1‑ Mtlpmo‑Mtbgl The ability to degrade alkali-treated corn cobs was significantly higher than that of the starting bacteria, and the total yield of cello-oligosaccharides increased by 57.11%, the total yield of cello-oligosaccharide acid increased by 129.91%, and the glucose yield increased by 212.75%. The present invention has important reference and guiding significance in improving the efficiency of cellulose degrading enzymes and has important value in reducing the cost of lignocellulosic biomass conversion.

Description

Technical Field

[0001] The invention relates to the field of agricultural biotechnology, and in particular to a method for improving the cellulose degradation ability of thermophilic myceliophthora and an engineering strain. Background Art

[0002] Cellulose, as the main component of lignocellulosic biomass, is composed of glucose structural units connected by β-1,4-glycosidic bonds. In the three-dimensional structure of cellulose, cellulose molecular chains are arranged parallel to each other, forming a highly crystalline structure through hydrogen bonds and van der Waals forces. The existence of these crystalline structures significantly enhances the stability and resistance to degradation of cellulose, making it difficult to be decomposed by biological enzymes.

[0003] The biodegradation of cellulose is traditionally believed to rely mainly on the synergistic effects of glycoside hydrolases such as cellobiohydrolases, endoglucanases, and β-glucosidases. In recent years, oxidoreductases such as lytic polysaccharide monooxygenases, as a new type of polysaccharide-degrading enzyme, have been found to participate in the biodegradation of cellulose by breaking the glycosidic bonds in the crystalline region of cellulose in an oxidative manner. However, there is no report that the simultaneous modification of microbial oxidoreductases and glycoside hydrolases can significantly improve their ability to degrade cellulose. Studies on the combined degradation of cellulose by oxidoreductases and glycoside hydrolases have only been studied in vitro using purified enzymes, which are limited to oxidoreductase lytic polysaccharide monooxygenases and glycoside hydrolases cellobiohydrolases / endoglucanases, and there are reports of antagonistic effects. For example, in the degradation of cellulose by cellobiohydrolase Cel7A, lytic polysaccharide monooxygenase LPMO9E reduced the yield of cellooligosaccharides by 14%, and in the degradation of cellulose by endoglucanase Cel5A, lytic polysaccharide monooxygenase LPMO9J reduced the yield of cellooligosaccharides by 60%.

[0004] Thermophilic Myceliophthora Myceliophthora thermophila ) is a thermophilic filamentous fungus chassis strain used in industry to produce cellulose degrading enzymes, and has high development and application value in the process of lignocellulose degradation and utilization. Although after years of research, several strains of thermophilic myceliophthora with high production of cellulose degrading enzymes have been obtained, such as the alkaline protease gene alp 1 defective strain. However, the high cost of cellulose degrading enzymes is still a bottleneck problem restricting the conversion and utilization of lignocellulosic biomass. Therefore, further improving the efficiency of cellulose degrading enzymes is a potential solution to this problem. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the defects of low cellulose conversion efficiency and high cost in the prior art. The purpose of the present invention is to provide a method for improving the cellulose degradation ability of Myceliophthora thermophila.

[0006] Another object of the present invention is to provide an engineered strain of Myceliophthora thermophila with improved cellulose degradation ability.

[0007] According to the method for improving the cellulose degradation ability of Myceliophthora thermophila, the method comprises the step of overexpressing homologous genes encoding lytic polysaccharide monooxygenase (LPMO) and genes encoding β-glucosidase (BGL) in Myceliophthora thermophila.

[0008] The amino acid sequence of the lytic polysaccharide monooxygenase is shown in SEQ ID NO:3, and the amino acid sequence of the β-glucosidase is shown in SEQ ID NO:4.

[0009] According to the method for improving the cellulose degradation ability of Myceliophthora thermophila of the present invention, the nucleotide sequence of the gene encoding the lytic polysaccharide monooxygenase is shown as SEQ ID NO: 1, and the nucleotide sequence of the gene encoding the β-glucosidase is shown as SEQ ID NO: 2.

[0010] According to the method for improving the cellulose degradation ability of Myceliophthora thermophila of the present invention, in order to increase the expression level of protease, the protease gene is preferably knocked out, so that the Myceliophthora thermophila is an alkaline protease gene defective type.

[0011] According to the engineered Myceliophthora thermophila strain with improved cellulose degradation ability of the present invention, the engineered Myceliophthora thermophila strain is a Myceliophthora thermophila strain that overexpresses homologous genes encoding lytic polysaccharide monooxygenase and genes encoding β-glucosidase.

[0012] The amino acid sequence of the lytic polysaccharide monooxygenase is shown in SEQ ID NO:3, and the amino acid sequence of the β-glucosidase is shown in SEQ ID NO:4.

[0013] According to the engineered Myceliophthora thermophila strain with improved cellulose degradation ability of the present invention, the engineered Myceliophthora thermophila strain is of alkaline protease gene defective type.

[0014] LPMO gene SEQ ID NO: 1

[0015] ATGAAGTCCTTCACCCTCACCACTCTGGCCGCCCTGGCTGGCAACGCCGCCGCTCACGCGACCTTCCAGGCCCTCTGGGTCGACGGCGTCGACTACGGCGCGCAGTGTGCCCGTCTGCCCGCGTCCAACTCGCCGGTCACCGACGTGACCTCCAACGCGATCCGCTGCAACGCCAACCCCTCGCCCGCTCGGGGCAAGTGCCCGGTCAAGGCCGGCTCGACCGTTACGGTCGAGATGCATCAGCAACCCGGTGACCGCTCGTGCAGCAGCGAGGCGATCGGCGGGGCGCACTACGGCCCCGTGATGGTGTACATGTCCAAGGTGTCGGACGCGGCGTCGGCGGACGGGTCGTCGGGCTGGTTCAAGGTGTTCGAGGACGGCTGGGCCAAGAACCCGTCCGGCGGGTCGGGCGACGACGACTACTGGGGCACCAAGGACCTGAACTCGTGCTGCGGGAAGATGAACGTCAAGATCCCCGCCGACCTGCCCTCGGGCGACTACCTGCTCCGGGCCGAGGCCCTCGCGCTGCACACGGCCGGCAGCGCGGGCGGCGCCCAGTTCTACATGACCTGCTACCAGCTCACCGTGACCGGCTCCGGCAGCGCCAGCCCGCCCACCGTCTCCTTCCCGGGCGCCTACAAGGCCACCGACCCGGGCATCCTCGTCAACATCCACGCCCCGCTGTCCGGCTACACCGTGCCCGGCCCGGCCGTCTACTCGGGCGGCTCCACCAAGAAGGCCGGCAGCGCCTGCACCGGCTGCGAGTCCACTTGCGCCGTCGGCTCCGGCCCCACCGCCACCGTCTCCCAGTCGCCCGGTTCCACCGCCACCTCGGCCCCCGGCGGCGGCGGCGGCTGCACCGTCCAGAAGTACCAGCAGTGCGGCGGCCAGGGCTACACCGGCTGCACCAACTGCGCGTCCGGCTCCACCTGCAGCGCGGTCTCGCCGCCCTACTACTCGCAGTGCGTC。

[0016] BGL gene, SEQ ID NO: 2

[0017]

[0018] The amino acid sequence of LPMO is shown in SEQ ID NO: 3, and the amino acid sequence of BGL is shown in SEQ ID NO: 4.

[0019] Amino acid sequence of LPMO, SEQ ID NO: 3:

[0020] MKSFTLTTLAALAGNAAAHATFQALWVDGVDYGAQCARLPASNSPVTDVTSNAIRCNANPSPARGKCPVKAGSTVTVEMHQQPGDRSCSSEAIGGAHYGPVMVYMSKVSDAASADGSSGWFKVFEDGWAKNPSGGSGDDDYWGTKDLNSCCGKMNVKIPADL PSGDYLLRAEALALHTAGSAGGAQFYMTCYQLTVTGSGSASPPTVSFPGAYKATDPGILVNIHAPLSGYTVPGPAVYSGGSTKKAGSACTGCESTCAVGSGPTATVSQSPGSTATSAPGGGGGCTVQKYQQCGGQGYTGCTNCASGSTCSAVSPPYYSQCV.

[0021] The amino acid sequence of BGL, SEQ ID NO: 4:

[0022] *.

[0023] In some embodiments of the present invention, the thermophilic myceliophthora engineered strain is cultured at 40-50°C for 2-4 days, preferably at 45°C for 3 days. The fermentation medium includes a carbon source, a nitrogen source, an inorganic salt, and trace metal elements. The carbon source includes, but is not limited to, one or more of glucose, sucrose, corn cobs, corn stalks, wheat straw, and rice straw. The nitrogen source includes, but is not limited to, one or more of yeast extract, peptone, trisodium citrate, ammonium salts, and nitrates. The inorganic salts include, but are not limited to, one or more of sulfates, hydrochlorides, nitrates, and phosphates. The trace metal element source includes, but is not limited to, one or more of sulfates, hydrochlorides, and nitrates of potassium, calcium, magnesium, iron, copper, zinc, and manganese.

[0024] In some embodiments of the present invention, the 100 mL fermentation medium contains: 2 mL 50× Vogel's solution, 2 g corn cob, 4 μM copper sulfate, and 98 mL water.

[0025] The beneficial effects of the present invention are:

[0026] The thermophilic myceliophthora genetically engineered bacteria Δ alp 1- Mtlpmo-Mtbgl The ability to degrade microcrystalline cellulose was significantly higher than that of the starting bacteria, and the total production of cellooligosaccharides increased by 68.53%, the total production of cellooligosaccharide acid increased by 189.08%, and the glucose production increased by 254.14%. alp 1- Mtlpmo- Mtbgl The ability to degrade alkali-treated corn cobs was significantly higher than that of the starting bacteria, and the total yield of cello-oligosaccharides increased by 57.11%, the total yield of cello-oligosaccharide acid increased by 129.91%, and the glucose yield increased by 212.75%. The present invention has important reference and guiding significance in improving the efficiency of cellulose degrading enzymes and has important value in reducing the cost of lignocellulosic biomass conversion. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Thermophilic Myceliophthora alp 1 and genetically engineered bacteria Δ alp 1- Mtlpmo SDS-PAGE analysis results of fermentation broth, 1: Thermophilic Myceliophthora starting strain Δ alp 1 Fermentation broth, 2: Genetically engineered thermophilic myceliophthora strain Δ alp 1- Mtlpmo Fermentation broth;

[0028] Figure 2 Thermophilic Myceliophthora genetically engineered strains Δ alp 1 -Mtlpmo and Δ alp 1- Mtlpmo-Mtbgl SDS-PAGE analysis results of fermentation broth, 1: Genetically engineered thermophilic myceliophthora strain Δ alp 1 -Mtlpmo Fermentation broth, 2: Genetically engineered thermophilic myceliophthora Δ alp 1- Mtlpmo-Mtbgl Fermentation broth;

[0029] Figure 3 Thermophilic Myceliophthora alp 1. Genetically engineered bacteria Δ alp 1 -Mtlpmo and Δ alp 1-Mtlpmo- Mtbgl Ion chromatography test results of cellooligosaccharides produced by degradation of microcrystalline cellulose in fermentation broth;

[0030] Figure 4 Thermophilic Myceliophthora alp 1. Genetically engineered bacteria Δ alp 1 -Mtlpmo and Δ alp 1- Mtlpmo-Mtbgl Ion chromatography test results of cellulooligosaccharide acid produced by degradation of microcrystalline cellulose by fermentation broth;

[0031] Figure 5 Thermophilic Myceliophthora alp 1. Genetically engineered bacteria Δ alp 1 -Mtlpmo and Δ alp 1- Mtlpmo-Mtbgl Ion chromatography test results of cellulosic oligosaccharides produced by fermentation broth degradation of alkali-treated corncobs;

[0032] Figure 6 Thermophilic Myceliophthora alp 1. Genetically engineered bacteria Δ alp 1 -Mtlpmo and Δ alp 1- Mtlpmo-Mtbgl Ion chromatography results of cellulosic acid produced by fermentation broth degradation of alkali-treated corncobs. DETAILED DESCRIPTION

[0033] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0034] 1. Strains and vectors

[0035] Thermomycete ATCC42464 is an existing industrial filamentous fungus used to produce cellulase and is stored in the American Type Culture Collection. alp 1. Used as a starting bacteria for genetic modification.

[0036] 2. Culture medium and other reagents

[0037] The medium used for culturing Myceliophthora thermophila was potato dextrose agar medium;

[0038] Protoplast regeneration medium (100 mL): 2 mL 50 × Vogel's solution, 2 g sucrose, 18.2 g sorbitol, 0.75 g agarose, dilute to 100 mL;

[0039] 50 × Vogel's solution (1 L): 125 g trisodium citrate dihydrate, 250 g potassium dihydrogen phosphate, 100 g ammonium nitrate, 10 g magnesium sulfate heptahydrate, 5 g calcium chloride dihydrate, 5 mL trace element solution, 2.5 mL 0.1 mg / mL biotin solution, 5 mL chloroform, dilute to 1000 mL;

[0040] Trace element solution (100 mL): 5 g citric acid monohydrate, 5 g zinc sulfate heptahydrate, 1 g ammonium ferrous sulfate hexahydrate, 0.25 g copper sulfate pentahydrate, 0.05 g manganese sulfate monohydrate, 0.05 g boric acid, 0.05 g sodium molybdate dihydrate, dilute to 100 mL;

[0041] Genetically engineered bacteria fermentation medium (100 mL): 2 mL 50 × Vogel's solution, 2 g corn cob, 4 μM copper sulfate, 98 mL water.

[0042] Example 1 Preparation of Escherichia coli recombinant vector

[0043] Extraction of mRNA and acquisition of cDNA of Myceliophthora thermophila: Myceliophthora thermophila mycelium was collected and ground into powder in liquid nitrogen; 800 μL Trizol reagent was added to 100 mg of myceliophthora, mixed by blowing, and placed at room temperature for 5 minutes; 200 μL chloroform was added, shaken vigorously for 15 seconds, placed at room temperature for 3 minutes, and centrifuged at 4 ℃ 12000 rpm for 15 minutes; the supernatant was taken, an equal volume of isopropanol was added, placed at room temperature for 10 minutes, and centrifuged at 4 ℃ 12000 rpm for 10 minutes; the supernatant was discarded, and the precipitate was washed once with 70% ethanol, and the precipitate was dried in the air and then an appropriate amount of RNase-Free deionized water was added to dissolve RNA. The cDNA template was obtained using a reverse transcription kit. The coding genes of LPMO and BGL were obtained by PCR amplification using the cDNA of Myceliophthora thermophila as a template. The coding genes of LPMO and BGL were connected to the overexpression vectors SESA-Neo and pPH1-Zeo respectively by seamless cloning to obtain the recombinant products SESA-Neo-LPMO and pPH1-Zeo-BGL. The obtained recombinant products were transformed into the cloning competent cells Trans1-T1, and the transformants were picked for PCR verification and sequencing after culturing in a 37°C incubator for 12 hours. The primers and primer sequences used for PCR amplification of the LPMO gene are as follows:

[0044] LPMO-F: 5'TACTACAATTATTAATTAAAATGAAGTCCTTCACCCTCAC3' (SEQ ID NO: 5),

[0045] LPMO-R: 5'TAAGAAATTCGGATCCTCACTAGTGGTGGTGGTGGTGGTGGACGCACTGCGAGTAGTA3' (SEQ ID NO: 6);

[0046] The primers and primer sequences used for PCR amplification of the BGL gene are as follows:

[0047] BGL-F: 5'ATCAACCAAGACATCATTCACAATGACCCTTCAAGCCTTTGC3' (SEQ ID NO: 7),

[0048] BGL-R: 5'AAGAAATTCGGATCCTCATTAGTGGTGGTGGTGGTGGTGTACTCGGAAGCTCCCCGTCAGCC (SEQ ID NO: 8).

[0049] Example 2 Construction of Genetically Engineered Myceliophthora Thermophylla

[0050] Protoplast preparation: Thermomycete alp 1 The spore suspension was spread on a potato dextrose agar plate and cultured at 37 °C for 16 h. The germinated mycelium was collected and placed in 20 mL of 10 mg / mL lysing enzyme solution and digested at 75 rpm and 28 °C for 2 h. Filter and collect the filtrate into a 50 mL centrifuge tube, and centrifuge at 3000 rpm and 4 ℃ for 10 minutes; then add 10 mL STC solution (1.2 M sorbitol, 50 mM calcium chloride, 35 mM sodium chloride, pH 7.0) to suspend the protoplasts, and centrifuge at 3000 rpm and 4 ℃ for 10 minutes; discard the supernatant, add 200 μL STC solution to resuspend the protoplasts, gently shake and mix the 50 μL PEG solution and gene fragments, and incubate on ice for 20 minutes; then add 2 mL PEG solution, shake and mix, incubate at room temperature for 5 minutes, add 4 mL STC solution, and then mix with protoplast regeneration medium containing antibiotics (100 μg / mL G418 or 100 μg / mL Zeocin), and culture at 45 ℃ for 3 days until transformants grow.

[0051] Transformants were selected and cultured on potato dextrose agar plates for 3 days, after which genomic DNA was extracted and used as a template for PCR verification. Positive transformants were then cultured until sporulation occurred, and then 10 6 The concentration of spores / mL was inoculated into the fermentation medium of genetically engineered bacteria, and the expression was determined by SDS-PAGE of the fermentation broth on the third day ( Figure 1 and Figure 2According to the above method, the thermophilic myceliophthora genetically engineered bacteria Δ alp 1 is used as the host, and the gene fragment of the recombinant vector SESA-Neo-LPMO is transformed to obtain the genetically engineered bacterium Δ alp 1 -Mtlpmo ; Then the thermophilic myceliophthora genetically engineered bacteria Δ alp 1 -Mtlpmo As the host, the gene fragment of the recombinant vector pPH1-Zeo-BGL was transformed to obtain the genetically engineered bacterium Δ alp 1- Mtlpmo-Mtbgl .

[0052] Example 3 Degradation of microcrystalline cellulose by genetically engineered Myceliophthora thermophila

[0053] The following reaction system (600 μL) was used: 50 mM pH 5.0 acetic acid-sodium acetate buffer, 4% microcrystalline cellulose, and 150 μL of the third day fermentation broth of the genetically engineered bacteria or the starting bacteria prepared in Example 2. The system without adding microcrystalline cellulose and the third day fermentation broth of the genetically engineered bacteria was used as a control, and the reaction system was repeated 3 times. The reaction was carried out at 1000 rpm and 45 °C, and was terminated by boiling after 24 hours. The production of cellooligosaccharides and cellooligosaccharide acid products was detected by ion chromatography.

[0054] The amount of cellooligosaccharide produced Figure 3 As shown, the thermophilic myceliophthora starting fungus Δ alp 1. Genetically engineered bacteria Δ alp 1- Mtlpmo and Δ alp 1- Mtlpmo-Mtbgl The fermentation broth degraded microcrystalline cellulose to produce 3475.30 μg / mL, 4009.46 μg / mL and 5856.84 μg / mL of cellooligosaccharides, of which the glucose production was 1507.67 μg / mL, 1535.39 μg / mL and 5339.24 μg / mL, respectively. Figure 4 As shown, the thermophilic myceliophthora starting fungus Δ alp 1. Genetically engineered bacteria Δ alp 1- Mtlpmo and Δ alp 1- Mtlpmo-Mtbgl The fermentation broth degraded microcrystalline cellulose to produce 131.97 μg / mL, 760.97 μg / mL and 381.51 μg / mL cellooligosaccharide acid, respectively. alp 1- Mtlpmo-Mtbgl The yields of cellobiose and cellobionic acid produced were lower than those of the genetically engineered strain Δ alp 1- Mtlpmo IntegrationFigure 3 and Figure 4 The results showed that the use of the thermophilic myceliophthora genetically engineered bacteria Δ alp 1- Mtlpmo-Mtbgl The ability to degrade microcrystalline cellulose was significantly higher than that of the starting bacteria, with the total production of cellooligosaccharides increased by 68.53%, the total production of cellooligosaccharide acid increased by 189.08%, and the glucose production increased by 254.14%. It can be seen that the simultaneous overexpression of the LPMO gene encoding the lytic polysaccharide monooxygenase and the BGL gene encoding the β-glucosidase can significantly enhance the ability of thermophilic Myceliophthora to degrade microcrystalline cellulose.

[0055] Example 4 Degradation of alkaline-treated corn cobs by genetically engineered thermophilic myceliophthora

[0056] The following reaction system (600 μL) was used: 50 mM pH 5.0 acetic acid-sodium acetate buffer, 4% alkali-treated corn cobs, and 150 μL of the third-day fermentation broth of the genetically engineered bacteria or the starting bacteria prepared in Example 2. The third-day fermentation broth without microcrystalline cellulose and genetically engineered bacteria was used as a control, and the reaction system was repeated 3 times. The reaction was carried out at 1000 rpm and 45 °C, and was terminated by boiling after 24 hours. The production of cellooligosaccharides and cellooligosaccharide acid products was detected by ion chromatography.

[0057] The amount of cellooligosaccharide produced Figure 5 As shown, the thermophilic myceliophthora starting fungus Δ alp 1. Genetically engineered bacteria Δ alp 1- Mtlpmo and Δ alp 1- Mtlpmo-Mtbgl The fermentation broth degraded the alkali-treated corncobs to produce 5548.72 μg / mL, 6630.61 μg / mL, and 8717.53 μg / mL of cellooligosaccharides, of which the glucose production was 2547.01 μg / mL, 2826.99 μg / mL, and 7965.83 μg / mL, respectively. Figure 6 As shown, the thermophilic myceliophthora starting fungus Δ alp 1. Genetically engineered bacteria Δ alp 1- Mtlpmo and Δ alp 1- Mtlpmo-Mtbgl The fermentation broth degraded the alkaline-treated corncobs to produce 265.59 μg / mL, 745.08 μg / mL and 610.62 μg / mL of cellooligosaccharide acid, respectively. alp 1- Mtlpmo-Mtbgl The yields of cellobiose and cellobionic acid produced were lower than those of the genetically engineered strain Δ alp 1- Mtlpmo IntegrationFigure 5 and Figure 6 The results showed that the use of the thermophilic myceliophthora genetically engineered bacteria Δ alp 1- Mtlpmo-Mtbgl The ability to degrade alkali-treated corn cobs was significantly higher than that of the starting bacteria, with the total yield of cellooligosaccharides increased by 57.11%, the total yield of cellooligosaccharide acid increased by 129.91%, and the glucose yield increased by 212.75%. It can be seen that the simultaneous overexpression of the LPMO gene encoding the lytic polysaccharide monooxygenase and the BGL gene encoding the β-glucosidase can significantly enhance the ability of Thermophilic Myceliophthora to degrade alkali-treated corn cobs.

[0058] The above embodiments are only used to explain the technical solution of the present application and do not limit the protection scope of the present application.

Claims

1. A method for improving the cellulose degradation ability of Myceliophthora thermophila, characterized in that: The method comprises the steps of overexpressing homologous genes encoding a lytic polysaccharide monooxygenase and a gene encoding a beta-glucosidase in Myceliophthora thermophila, wherein the amino acid sequence of the lytic polysaccharide monooxygenase is shown in SEQ ID NO: 3, the amino acid sequence of the beta-glucosidase is shown in SEQ ID NO: 4, and the Myceliophthora thermophila is an alkaline protease gene-deficient type.

2. The method for improving the cellulose degradation ability of Myceliophthora thermophila according to claim 1, characterized in that: The nucleotide sequence of the gene encoding the lytic polysaccharide monooxygenase is shown in SEQ ID NO: 1, and the nucleotide sequence of the gene encoding the β-glucosidase is shown in SEQ ID NO:

2.

3. An engineered strain of Myceliophthora thermophila with improved cellulose degradation ability, characterized in that: The thermophilic Myceliophthora engineered strain is a thermophilic Myceliophthora strain that overexpresses homologous genes encoding a lytic polysaccharide monooxygenase and a gene encoding a β-glucosidase, wherein the amino acid sequence of the lytic polysaccharide monooxygenase is shown in SEQ ID NO: 3, the amino acid sequence of the β-glucosidase is shown in SEQ ID NO: 4, and the thermophilic Myceliophthora is an alkaline protease gene defective type.

4. The engineered strain of Myceliophthora thermophila with improved cellulose degradation ability according to claim 3, characterized in that The nucleotide sequence of the gene encoding the lytic polysaccharide monooxygenase is shown in SEQ ID NO: 1, and the nucleotide sequence of the gene encoding the β-glucosidase is shown in SEQ ID NO: 2.

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