Application of GH48 / GH57 / GH9 family gene carried by bacillus altitudinis H1 in improvement of corn straw rumen fermentation digestibility

Abstract

The invention provides an application of GH48 / GH57 / GH9 family genes carried by bacillus altitudinis H1 in improvement of corn straw rumen fermentation digestibility, and belongs to the technical field of degrading bacteria. According to the invention, a cellulose degradation strain H1 is separated and screened from a goat rumen content, and the preservation number of the strain is GDMCC No: 67152. The invention further discloses a preparation method of the cellulose degradation strain H1. An in-vitro fermentation experiment shows that the soluble carbohydrate content and the lignin content of the corn straw fermented by the H1 strain are remarkably reduced, the 48-hour gas production rate is remarkably reduced, and the propionic acid content is also remarkably reduced. The result shows that the H1 strain has stronger lignin decomposition capability and preferentially degrades hemicellulose and pectin. The H1 strain provided by the invention is proved to have a good corn straw degradation effect.

Description

Technical Field

[0001] This invention belongs to the field of degradation bacteria technology, specifically relating to the application of the GH48 / GH5_7 / GH9 family genes carried by Bacillus hygroscopicus H1 in improving the rumen fermentation digestibility of corn straw. Background Technology

[0002] Corn stalks are a major agricultural waste residue after corn harvest, primarily composed of stems, leaves, cobs, and husks. They are mainly composed of plant cell walls, with cellulose (35%–50%), hemicellulose (20%–35%), and lignin (15%–25%) forming a complex cross-linked barrier against degradation. Cellulose provides mechanical strength, hemicellulose enhances toughness, and lignin acts as a natural "glue" to encapsulate polysaccharides, making them difficult for microorganisms or enzymes to directly decompose. In addition, stalks also contain small amounts of protein, ash, and soluble sugars. Their high crystallinity and lignification are major bottlenecks to biodegradation; therefore, pretreatment is a crucial step in improving degradation efficiency.

[0003] How to efficiently utilize agricultural byproducts such as corn stalks and convert them into bioenergy or high-value-added products has become a core research topic in the fields of biomass energy and biorefining. While traditional physicochemical treatment methods can partially realize the resource utilization of stalks, they often suffer from high energy consumption, significant pollution, and poor economic viability. In contrast, microbial-based bioconversion technology shows great potential due to its environmental friendliness, mild conditions, and high selectivity; however, the types of degrading bacteria targeting corn stalks are currently limited. Summary of the Invention

[0004] This invention provides the application of the GH48 / GH5_7 / GH9 family genes carried by Bacillus hygroscopicus H1 in improving the rumen fermentation digestibility of corn straw, wherein Bacillus hygroscopicus H1 has good corn straw degradation ability.

[0005] This invention provides a highland Bacillus with fiber degradation capabilities (… Bacillus altitudinis The preservation number of the Bacillus hygroscopicus H1 is GDMCC No:67152.

[0006] In a preferred embodiment of the present invention, the fiber degradation capability includes the degradation of at least one of the following: cellulose, hemicellulose and lignin.

[0007] The present invention also provides a microbial agent for degrading straw, comprising the above-mentioned Bacillus hygroscopicus H1.

[0008] The present invention also provides a method for preparing the above-mentioned bacterial agent, comprising inoculating the strain of Bacillus hygroscopicus H1 onto LB agar plates for aerobic culture, picking single colonies into LB broth culture medium for aerobic culture, and then performing scale-up culture to obtain the bacterial agent.

[0009] In a preferred embodiment of the present invention, the LB agar plate contains 5 g / L yeast extract, 10 g / L tryptone, 10 g / L sodium chloride and 15 g / L agar powder.

[0010] In a preferred embodiment of the present invention, the LB broth culture medium contains 5 g / L yeast extract, 10 g / L tryptone, and 10 g / L sodium chloride.

[0011] In a preferred embodiment of the present invention, the temperature for aerobic culture is 37°C.

[0012] In a preferred embodiment of the present invention, the inoculum size during the expanded culture is 2%.

[0013] The present invention also provides the application of the above-mentioned Bacillus hygroscopicus H1 or the above-mentioned inoculant in the degradation of straw.

[0014] In a preferred embodiment of the present invention, the straw includes corn straw.

[0015] Beneficial effects: This invention isolates and screens a fiber-degrading bacterial strain from goat rumen contents ( Bacillus altitudinis The whole genome analysis of strain H1 showed that the strain has a large number of carbohydrate-associated enzymes (CAZy), including potential cellulases (such as GH5 and GH9) and lignin-degrading enzymes (such as AA1 laccase), indicating that the strain has a unique ability to synergistically degrade lignocellulose; and the presence of 6 secondary metabolite synthesis gene clusters (such as NRPS) may enhance its ecological competitiveness.

[0016] In vitro fermentation experiments revealed that the soluble carbohydrate and lignin contents of corn stalks significantly decreased after fermentation with the H1 strain described in this invention, along with a significant reduction in gas production over 48 hours and a significant decrease in propionic acid content. This indicates that the H1 strain possesses a stronger lignin-degrading ability and preferentially degrades hemicellulose and pectin. This demonstrates that the H1 strain described in this invention exhibits excellent corn stalk degradation performance.

[0017] Biological Preservation Information Highland Bacillus ( Bacillus altitudinis H1 was deposited on October 23, 2025 at the Guangdong Provincial Microbial Culture Collection Center (GDMCC), located at the Institute of Microbiology, Guangdong Academy of Sciences, 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, with accession number GDMCC No:67152. Attached Figure Description

[0018] Figure 1 This is a diagram of H1 colony morphology. Figure 2 The image shows the destaining results of the isolated strain using Congo red staining. Figure 3 Phylogenetic tree of strain H1; Figure 4 for Bacillus altitudinis H1 genome loop diagram; Figure 5 A statistical graph illustrating the annotation of carbohydrate-active enzymes in the genome of strain H1. Detailed Implementation

[0019] This invention provides a highland Bacillus with fiber degradation capabilities (… Bacillus altitudinis The preservation number of the Bacillus hygroscopicus H1 is GDMCC No:67152.

[0020] This invention isolates the bacterium H1 with cellulose degradation potential from sheep rumen contents using a dilution plating method. Its cellulase production capacity is preliminarily evaluated using Congo red staining. The ratio of hydrolysis zone diameter to colony diameter (D / d) is 4.6, and the decolorization zone is clear and distinct, indicating that the strain has a strong cellulase production capacity and a strong fiber degradation ability. After fermentation treatment with strain H1, the lignin ADL content in corn straw is significantly reduced, indicating that strain H1 has a strong lignin decomposition ability. The neutral detergent fiber (NDF) content in the straw is also reduced after treatment with strain H1, indicating that strain H1 can improve fiber degradation efficiency. Furthermore, it exhibits strong hemicellulase activity, effectively degrading hemicellulose and pectin. Therefore, the fiber degradation ability of strain H1 in this invention is mainly reflected in the degradation of at least one of the following: cellulose, hemicellulose, and lignin.

[0021] The present invention also provides a microbial agent for degrading straw, comprising the above-mentioned Bacillus hygroscopicus H1.

[0022] This invention uses strain H1 as the active ingredient of the bacterial agent, and generally requires that the content of strain H1 in the bacterial agent is not less than 1×10⁻⁶. 6 CFU / g.

[0023] The present invention also provides a method for preparing the above-mentioned bacterial agent, comprising inoculating the strain of Bacillus hygroscopicus H1 onto LB agar plates for aerobic culture, picking single colonies into LB broth culture medium for aerobic culture, and then expanding the culture to obtain the biological agent.

[0024] The application inoculates the frozen strain plate to the LB agar plate for aerobic culture, the LB agar plate includes components with the following concentrations: yeast extract 5 g / L, tryptone 10 g / L, sodium chloride 10 g / L and agar powder 15 g / L. The temperature of the aerobic culture is 37℃.

[0025] The application picks single colony to 5 mL LB broth for aerobic culture after the aerobic culture, the LB broth includes components with the following concentrations: yeast extract 5 g / L, tryptone 10 g / L and sodium chloride 10 g / L, the temperature of the aerobic culture is 37℃. Accompanied by shaking, the shaking frequency is 220 rpm, and the aerobic shaking culture is 6 h, to obtain the seed liquid.

[0026] The application carries out scale-up culture to the seed liquid, including inoculating the seed liquid to 100 mL LB broth at a ratio of 2%, aerobic shaking culture at 37℃ for 12 h to obtain the biological agent.

[0027] The application also provides the application of the above-mentioned Bacillus altitudinis H1 in degrading straw.

[0028] The straw includes corn straw. In the embodiment of the application, it is found through in-vitro fermentation experiment that the contents of soluble carbohydrates and lignin of corn straw after fermentation by the H1 strain of the application are significantly reduced, the gas production amount is significantly reduced in 48 h, and the content of propionic acid is also significantly reduced. It is shown that the H1 strain has stronger lignin decomposition capacity, and preferentially degrades hemicellulose and pectin. It is proved that the H1 strain of the application has good corn straw degradation effect.

[0029] In order to further illustrate the application, the application of the GH48 / GH5_7 / GH9 family gene carried by the Bacillus altitudinis H1 in improving rumen fermentation and digestion rate of corn straw is described in detail in combination with examples below, but they cannot be understood as limiting the protection scope of the application.

[0030] Example 1 1. Fiber-degrading bacteria separation and screening 1.1 Test materials (1) Strain source: collected from goat rumen contents (2) Culture medium: LB culture medium: tryptone 10 g, yeast extract 5 g, sodium chloride 1 g and distilled water 1000 mL; Carboxymethylcellulose sodium (CMC-Na) culture medium: carboxymethylcellulose sodium 15 g, tryptone 2 g, magnesium sulfate 0.2 g, sodium chloride 1 g, potassium dihydrogen phosphate 1 g, yeast extract 1 g and distilled water 1000 mL.

[0031] 1.2 Test method (1) Isolation: Collect goat rumen contents and add them to an Erlenmeyer flask containing 100 mL of sterile water. Shake at 30℃ and 160 r / min for 30 min. Take 1 mL of the supernatant and spread it on CMC-Na medium using the dilution plating method. Incubate upside down in a 30℃ incubator for 48 h. Pick single colonies with obvious clear zones and streak them onto fresh CMC-Na plates. Incubate at 37℃ for 24-48 h. Repeat 3-5 times until a pure culture is obtained.

[0032] (2) Screening: The isolated and purified strains were inoculated onto CMC-Na medium using the spot inoculation method and incubated upside down in a 30℃ incubator for 48 h. Then, 20 mL of 1 mg / mL Congo red solution was added for staining for 30 min. After staining, 20 mL of 1 mol / L NaCl solution was added for decolorization for 30 min. The colony diameter (d) and the diameter of the surrounding decolorization zone (D) were observed and measured, and the ratio of the decolorization zone diameter to the colony diameter (D / d) was calculated. Colonies with a larger ratio (D / d) were screened and stored for later use.

[0033] Bacteria were isolated and purified from the collected goat rumen contents using the dilution plating method. The colony morphology of H1 was as follows: Figure 1 The colonies shown are round, raised (3.0 ± 0.5 mm in diameter), with a smooth, milky-white surface and neat edges. Screening was performed using Congo red staining medium; strain H1 showed a decolorization zone (…). Figure 2 (i.e., has fiber degradation ability).

[0034] Measurements showed that the diameter of the decolorization zone (D) of strain H1 was 5.1 mm, and the colony diameter (d) was 1.1 mm, with a ratio (D / d) of 4.6, indicating that the strain has a strong ability to produce the corresponding enzyme.

[0035] 2. Identification of fiber-degrading bacteria 2.1 Test Materials DNA was extracted from strain H1, and primers were designed based on the bacterial sequence information for PCR amplification. The 25 μL PCR reaction mixture consisted of: 12.5 μL Taq DNA Master Mix, 0.5 μL each of forward and reverse primers (10 μmol / L), 1.5 μL DNA template, and 10 μL ddH2O.

[0036] Amplification program: 94℃ pre-reaction for 3 min; 94℃ denaturation for 45 s, 58℃ annealing for 45 s, 72℃ extension for 2 min, 30 cycles; 72℃ extension for 10 min, storage at 4℃.

[0037] 27F (SEQ ID No. 1): AGAGTTTGATCMTGGCTCAG; 1492R (SEQ ID No. 2): GGTTACCTTGTTACGACTT; 2.2 Test method PCR products were detected by 1% agarose gel electrophoresis and sent to Meiji Biotech Co., Ltd. for sequencing. The whole genome resequencing of Bacillus altitudinis H1 used "2nd generation + 3rd generation" De novo sequencing to obtain Zero gap genomic data. The third generation of data was assembled using Unicycler and Flye software; the high-quality data of the second generation was used to correct the third generation results using pilon software, and the complete sequence was finally obtained. The sequence information was statistically analyzed; the genomic sequence was compared with the Nucleotide Sequence Database (NT). The sequencing results were queried for species by sequence similarity using the BLAST tool of PubMed, and the phylogenetic tree was constructed using MEGA6.

[0038] The sequencing results of strain H1 were compared using the BLAST tool in PubMed, and the results are shown in Figure 3 , the homology of strain H1 and Bacillus altitudinis (EU500930) reached 98.46%. In the phylogenetic tree, strain H1 and Bacillus altitudinis EU500930 were clustered into one class. According to the molecular biology identification results, the corn straw degrading strain H1 was named Bacillus altitudinis H1. Bacillus altitudinis Bacillus altitudinis

[0039] The whole genome resequencing of strain H1 used "2nd generation + 3rd generation" De novo sequencing to obtain Zero gap whole genome information. The off-line data of the second generation sequencing is shown in Table 1, a total of 1,096,979,666 bases were obtained, the percentage of bases with base recognition accuracy of more than 99.9% was 96.52%, and the high-quality reads acquisition rate was 94.05%. The statistics of the third generation sequencing data of De novo sequencing are shown in Table 2, the length of the genome was 883,161,554 bp, and the total sequence number was 88,461.

[0040] Table 1 Off-line data of second generation sequencing

[0041] In Table 1, Q20 (%): percentage of bases with base recognition accuracy of more than 99%; Q30 (%): percentage of bases with base recognition accuracy of more than 99.9%. HQ Reads: percentage of reads after high-quality acquisition.

[0042] ​​Table 2 Third-generation sequencing data

[0043] The third-generation off-line data was assembled using software, and then the second-generation data was used to correct the third-generation results, and finally the complete Zero gap sequence was obtained. The complete genome map is shown in Figure 4 The statistical results show that the genome size of the strain is 3,779,664 bp. The results of non-coding RNA genes in the H1 strain genome are shown in Table 3.

[0044] Table 3 Number of non-coding RNA genes in H1

[0045] The Carbohydrate-Active enZYmes Database (CAZy) includes enzyme families related to glycosidic bond degradation, modification and generation. It mainly includes five categories: glycoside hydrolases (Glycoside Hydrolases, GHs), glycosyl transferases (Glycosyl Transferases, GTs), polysaccharide lyases (Polysaccharide Lyases, PLs), carbohydrate esterases (Carbohydrate Esterases, CEs), and auxiliary active enzymes (Auxiliary Activities, AAs). In addition, the database also includes enzymes related to carbohydrate binding (Carbohydrate-Binding Modules, CBMs). The H1 gene was aligned with the CAZy database, and the results are shown in Table 4, Figure 5 As shown in Table 4, there are 124 carbohydrate-active enzymes in H1, most of which are CEs, GHs and GTs. The GH5_7 family (gene1711) of the strain is an endoglucanase gene, which has high specificity for crystalline cellulose in plant cell walls and can effectively destroy the structure of corn straw fiber, creating a site for subsequent enzyme action; the GH48 family (gene1709) is an exocellulase gene that can continuously hydrolyze the end of the chain produced by endoglucanase to generate cellobiose, which is a key component of the "endoglucanase + exocellulase" synergistic system; the GH9 family (gene1708) encodes a multifunctional cellulase with endoglucanase activity and cellobiose hydrolysis ability, which can adapt to the complex environment of corn straw cellulose and hemicellulose interweaving, enhance the degradation adaptability, and synergistically realize efficient degradation of corn straw cellulose.

[0046] Table 4 Statistics of carbohydrate-active enzyme genes

[0047] The results of predicting the secondary metabolite synthesis gene clusters of H1 by antismash software are shown in Table 5. A total of 6 regions were predicted to be secondary metabolite gene clusters, mainly involving ribosome synthesis and post-translational modification peptides (Ribosomally Synthesized and Post-translationally Modified Peptides, RiPPs), non-ribosomal peptide synthetase (Nonribosomal Peptide Synthetase, NRPS), RNA or DNA sequence containing Rev response element (Rev Response Element Containing, RRE-containing), type III polyketide synthase (Type III Polyketide Synthase, T3PKS), terpene, and beta-lactone. However, the MIBIG database did not identify the most similar compounds of the 6 regions.

[0048] Table 5 antiSMASH identified secondary metabolite gene cluster results

[0049] 3. In vitro fermentation simulation 3.1 Test materials (1) Fresh corn stalks were collected from the teaching and research base of South China Agricultural University in Guangdong Province, with stubble of 0.2-0.3 m. After drying at 105°C for 24 h, the feed samples were prepared by crushing.

[0050] (2) Rumen fluid was collected from Yuhai Food Slaughterhouse in Foshan City, Guangdong Province. After normal feeding for 2 h, the rumen fluid was collected using negative pressure method, filtered through 4 layers of gauze, and placed in a thermos bottle. CO2 was introduced to quickly return to the laboratory.

[0051] (3) Commercial Bacillus (VTR Biotechnology Co., Ltd., Zhuhai, China); 1×10 6 CFU / g Bacillus altitudinis H1 (H1). Bacillus altitudinis H1).

[0052] 3.2 Test design A single factor multiple repetition test design was used, consisting of two treatment groups and one control group, which were: (1) The treatment group added 1×10 6 CFU / g of commercial Bacillus (VTR Biotechnology Co., Ltd., Zhuhai, China); (2) The treatment group added 1×10 6 CFU / g of H1; (3) Blank control group without adding fiber-degrading bacteria.

[0053] After the gauze filtered rumen fluid was mixed with buffer to prepare artificial fermentation liquid, 200 mL of each group was added to the bean milk bag with a port (20 cm x 40 cm), and 1 g of feed sample was accurately weighed in the fiber analysis bag. Each group had 3 repeats, and after sealing, the glass beads were punched and placed in the fermentation liquid. After the air was discharged, it was sealed with a rubber plug and placed in a 39℃ water bath at 60 rpm for 48 h. The gas production was measured at 2 h, 4 h, 6 h, 8 h, 12 h, 24 h, 36 h, and 48 h with a disposable syringe.

[0054] 3.3 Sampling and treatment of corn stalks After fermentation, 10 mL of the fermentation liquid was centrifuged to obtain the clear supernatant, which was placed in a 4℃ refrigerator for standby. The sample bag was washed and placed in a 105℃ oven for 2 h, then the temperature was adjusted to 65℃ and continued to bake for 48 h. After taking out, it was placed in a desiccator to cool and weigh. After weighing, the fiber bag was cut open to take out the sample and stored in a sealed bag for determination of nutritional components.

[0055] 3.4 Determination index and method (1) Determination of corn stalk nutritional components The crude protein (CP) of corn stalk raw materials and fermented corn stalks was determined by Kjeldahl method. CP was determined by automatic Kjeldahl nitrogen analyzer (Kjeltec 18 automatic analyzer, FOSS Analytical AB, Hillerod, Denmark); Neutral detergent fiber (NDF) and acid detergent fiber (ADF) were determined by Van Soest method using automatic fiber analyzer (ANKOM A-19I fiber analyzer, ANKOM Company, Macedon, NY, USA); Water soluble carbohydrates (WSC) were determined by anthrone-concentrated sulfuric acid colorimetry; Ether extract (EE) was determined by Soxhlet extractor (Shanghai Xingjia Electronics Co., Ltd., Shanghai); Acid detergent lignin (ADL) was determined by ANKOM fiber analyzer.

[0056] The results of corn stalk nutritional component determination are shown in Table 6.

[0057] Table 6 Nutritional components of corn stalk raw materials (% DM)

[0058] (2) Corn stalk fermentation characteristics determination The dry matter (DM) of fermented corn stalk was determined by oven drying method: the nylon bag after digestion was washed with tap water until the water was clear, and then dried at 105°C to constant weight for dry matter determination; pH value was determined by pH meter; ammoniacal nitrogen (AN) was determined by phenol-sodium hypochlorite colorimetry; acetic acid (AA) and other volatile fatty acids (VFA) were determined by high-performance gas chromatograph (Agilent 7890B).

[0059] As shown in Table 7, the acetic acid content measured by comparing the commercial bacteria group and the control group increased, the acetic acid content measured by comparing the H1 group and the control group decreased, and there was no significant difference (P>0.05). The isobutyric acid content measured by comparing the two treatment groups and the control group was almost equal. The propionic acid content measured by comparing the commercial bacteria group and the control group increased significantly (P<0.05), and the propionic acid content measured by comparing the H1 group and the control group decreased significantly (P<0.05). The butyric acid content, ammoniacal nitrogen content and pH value measured by comparing the two treatment groups and the control group increased, but there was no significant difference (P>0.05). The isovaleric acid content and dry matter loss rate measured by comparing the two treatment groups and the control group decreased, but there was no significant difference (P>0.05). The valeric acid content measured by comparing the commercial bacteria group and the control group increased, and the valeric acid content measured by comparing the H1 group and the control group decreased, and there was no significant difference (P>0.05). P P P P P P As a volatile fatty acid component closely related to soluble carbohydrate fermentation, the decrease in propionic acid content may mean that H1 metabolism is more inclined to the degradation of recalcitrant fibers (hemicellulose, lignin) rather than preferentially utilizing easily fermentable substrates, or reflects its targeted degradation characteristics of straw fibers; At the same time, it is speculated that the microorganisms producing fiber-degrading enzymes in the fermentation system are more dominant, the abundance of propionic acid-producing bacteria is reduced, and the reduction of propionic acid synthesis may allocate more energy and carbon sources to fiber-degrading enzyme reactions, thereby strengthening the degradation efficiency and echoing the remodeling of fiber structure, and the whole or reflects the metabolic strategy of H1 to fiber degradation, helping the efficient in vitro fiber degradation and fermentation of straw.

[0060] Table 7 Effect of different bacteria on the fermentation characteristics of corn stalk

[0061] ​​​​​Means in the same row with different lowercase letters are significantly different (P < 0.05) P Means not sharing a common letter or no letter are not significantly different (P > 0.05) P >0.05), the same below.

[0062] (3) Analysis results of nutritional components of fermented corn stalks As shown in Table 8, the WSC content of the two treatment groups was significantly lower than that of the control group (P < 0.05), but there was no significant difference between the groups (P > 0.05). P P >0.05). The NDF content of the commercial bacteria group was higher than that of the control group, and the NDF content of the H1 group was lower than that of the control group, but there was no significant difference (P > 0.05). P >0.05). The ADF content of the commercial bacteria group was higher than that of the control group, and the ADF content of the H1 group was significantly higher than that of the control group (P < 0.05). P P P >0.05). The ADL content of the two treatment groups was significantly lower than that of the control group (P < 0.05), and the ADL content of the H1 group was significantly lower than that of the commercial bacteria group (P < 0.05). P >0.05). The cellulose content of the two treatment groups was significantly higher than that of the control group (P < 0.05), and the cellulose content of the H1 group was significantly higher than that of the commercial bacteria group (P < 0.05). P P >0.05). The hemicellulose content of the commercial bacteria group was higher than that of the control group, and the hemicellulose content of the H1 group was lower than that of the control group.

[0063] H1 has a significant promoting effect on straw in vitro fiber degradation fermentation, and the acid detergent lignin (ADL) content is significantly lower than that of the commercial bacteria group and the control group, showing strong decomposition ability for recalcitrant lignin; the hemicellulose content is significantly lower than that of the two groups, directly promoting fiber degradation; the water-soluble carbohydrate (WSC) content is significantly lower than that of the control group, providing sufficient energy for fiber degradation metabolism. Through efficient degradation of fiber components such as lignin and hemicellulose, it significantly promotes straw in vitro fiber degradation fermentation, and performs better than commercial bacteria in related degradation ability.

[0064] Table 8 Effect of different strains on nutritional components of fermented corn stalks (% DM)

[0065] ​​​​Although the above embodiments have been described in detail, it should be understood that these are only some embodiments of the present application, but not all embodiments. Other embodiments can be obtained on the basis of the above embodiments without creativity, and these embodiments all belong to the protection scope of the present application.

Claims

1. A type of Bacillus hygroscopicus with fiber-degrading capabilities ( Bacillus altitudinis H1, characterized in that, The preservation number of the Bacillus hygroscopicus H1 is GDMCC No:67152.

2. The *Bacillus hygroscopicus* H1 according to claim 1, characterized in that, The fiber degradation capability includes the degradation of at least one of the following: cellulose, hemicellulose, and lignin.

3. A microbial agent for degrading straw, characterized in that, Includes the Highland Bacillus H1 as described in claim 1 or 2.

4. The method for preparing the microbial agent according to claim 3, characterized in that, The process involves inoculating a strain of Bacillus hygroscopicus H1 onto LB agar plates for aerobic culture, picking single colonies and culturing them aerobically in LB broth, followed by expansion culture to obtain the bacterial agent.

5. The preparation method according to claim 4, characterized in that, The LB agar plate contains 5 g / L yeast extract, 10 g / L tryptone, 10 g / L sodium chloride, and 15 g / L agar powder.

6. The preparation method according to claim 4, characterized in that, The LB broth culture medium contains 5 g / L yeast extract, 10 g / L tryptone and 10 g / L sodium chloride.

7. The preparation method according to claim 4, characterized in that, The temperature for all aerobic cultures was 37°C.

8. The preparation method according to claim 4, characterized in that, The inoculum size for the expanded culture was 2%.

9. The application of the Bacillus hygroscopicus H1 of claim 1 or 2 or the inoculant of claim 3 in the degradation of straw.

10. The application according to claim 9, characterized in that, The straw includes corn stalks.

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