Saline-alkali-tolerant bacillus velezensis JT6, cellulose degrading enzyme secreted by same and application of cellulose degrading enzyme

Abstract

The invention relates to the technical field of microorganisms, in particular to a saline-alkaline-tolerant bacillus velezensis JT6, a cellulose degrading enzyme secreted by the same and application of the saline-alkaline-tolerant bacillus velezensis JT6. The bacillus velezensis JT6 disclosed by the invention is preserved in the China General Microbiological Culture Collection Center, the address is Institute of Microbiology, Chinese Academy of Sciences, 3 #, No.1 yard, West Beichen Road, Chaoyang District, Beijing, the preservation date is December 5, 2025, and the preservation number is CGMCC No.36918. The bacillus velezensis JT6 disclosed by the invention can be used for preparing the bacillus velezensis JT6. The strain has cellulose degradation activity, the degradation rate of corn straw is 48.8%, and the degradation rate of rice straw is 24.92%. The strain provided by the invention is used for rapid decomposition of straw returning, is safe to human and livestock, has no pollution to the environment, and has good development and application prospects.

Description

Technical Field

[0001] This invention relates to the field of microbial technology, and in particular to a salt-tolerant Bacillus berberis JT6 strain and its secreted cellulose-degrading enzyme and its applications. Background Technology

[0002] Northeast my country is a crucial grain production base, and its sustainable agricultural development is strategically vital for ensuring national food security. However, the region's widespread saline-alkali soils suffer from poor structure, low fertility, and lack of organic matter, severely restricting soil productivity and crop growth. Simultaneously, the large quantities of crop straw (such as corn and rice straw) generated annually are often burned or piled up on-site due to a lack of efficient and environmentally friendly degradation methods, resulting in resource waste and exacerbating environmental pollution and ecological degradation. Therefore, developing straw-degrading microbial resources suitable for saline-alkali and other adverse conditions is of great significance for promoting the resource utilization of straw, improving saline-alkali soil structure, and facilitating circular agricultural development.

[0003] Currently, straw treatment methods mainly include physical, chemical, and biodegradation. Among these, microbial degradation technology has attracted much attention due to its environmental friendliness, mild conditions, and ability to simultaneously improve soil. Cellulose, as a major component of straw, requires efficient degradation for resource utilization. Many types of microorganisms in nature can secrete cellulase, among which common fungi include *Trichoderma* (*Trichoderma*). Trichoderma Aspergillus ( ) Aspergillus ) etc.; common bacteria include Bacillus spp. ( Bacillus ), Pseudomonas spp. Pseudomonas However, most reported cellulose-degrading bacteria have weak adaptability to adverse conditions such as salinity and alkalinity, which limits their effectiveness in practical applications. Furthermore, the inherent high pH, ​​high salinity, and poor nutrient content of saline-alkali soils further inhibit the survival and functional expression of common degrading bacteria. Therefore, screening microbial strains that possess both high cellulose degradation capabilities and tolerance to saline-alkali stress has become a crucial breakthrough in solving the synergistic problem of straw degradation and soil improvement in this region. Summary of the Invention

[0004] The purpose of this invention is to provide a salt-tolerant Bacillus berberis JT6 strain and its secreted cellulose-degrading enzyme and its applications.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a salt- and alkali-tolerant strain of Bacillus belye ( Bacillus velezensisJT6 is deposited at the China General Microbiological Culture Collection Center (CGMCC), Institute of Microbiology, Chinese Academy of Sciences, No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing, on December 5, 2025, with accession number CGMCC No. 36918.

[0006] The present invention also provides the aforementioned Bacillus belesiensis ( Bacillus velezensis Application of JT6 in the preparation of products with filter paper enzyme activity.

[0007] The present invention also provides the aforementioned Bacillus belesiensis ( Bacillus velezensis Application of JT6 in the preparation of products with endo-β-1,4-glucanase activity.

[0008] The present invention also provides the aforementioned Bacillus belesiensis ( Bacillus velezensis Application of JT6 in the preparation of products with exo-β-1,4-glucanase activity.

[0009] The present invention also provides the aforementioned Bacillus belesiensis ( Bacillus velezensis Application of JT6 in the preparation of products with β-glucosidase activity.

[0010] The present invention also provides the aforementioned Bacillus belesiensis ( Bacillus velezensis Application of JT6 in the preparation of products with hemicellulase activity.

[0011] The present invention also provides the aforementioned Bacillus belesiensis ( Bacillus velezensis Application of JT6 in the preparation of products that combine filter paper enzyme activity, endo-β-1,4-glucanase activity, exo-β-1,4-glucanase activity, β-glucosidase activity and hemicellulase activity.

[0012] The present invention also provides the aforementioned Bacillus belesiensis ( Bacillus velezensis Application of JT6 in the degradation of cellulose.

[0013] The present invention also provides the aforementioned Bacillus belesiensis ( Bacillus velezensis JT6 has applications in both degrading crop straw and improving saline-alkali soil, wherein the straw is corn straw and / or wheat straw.

[0014] This invention also provides a method for degrading crop straw, comprising the following steps: reacting crop straw with the aforementioned Bacillus belye (… Bacillus velezensis JT6 mixed fermentation.

[0015] The present invention has the following advantages: This invention utilizes Bacillus belye, a bacterium screened from saline-alkali soil. Bacillus velezensisJT6 has the ability to degrade cellulose. The activity of filter paper enzyme (FPA) of this strain is 23.98 U / mL, the activity of endopeptidase-β-1,4-glucanase (CL) is 1.12 U / mL, the activity of exopeptidase-β-1,4-glucanase (CBH) is 0.40 U / mL, the activity of β-glucosidase (β-GC) is 1.45 U / mL, and the activity of hemicellulose (ACX) is 0.066 U / mL.

[0016] This strain also promotes the degradation of straw, with a degradation rate of 48.8% for corn straw and 24.92% for rice straw.

[0017] The strains of this invention also have the ability to tolerate salt and alkali.

[0018] The strain of this invention can be used for straw return to the field, which can quickly decompose straw, is safe for humans and animals, and does not pollute the environment, and has good development and application prospects.

[0019] Preservation Instructions

[0020] Bacillus belesiensis ( Bacillus velezensis JT6 is deposited at the China General Microbiological Culture Collection Center (CGMCC), Institute of Microbiology, Chinese Academy of Sciences, No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing, on December 5, 2025, with accession number CGMCC No. 36918. Attached Figure Description

[0021] Figure 1 Morphological characteristics of salt-tolerant strains; Figure 2 The Congo red staining effect of cellulose-degrading bacteria JT6; Figure 3 Phylogenetic tree of cellulose-degrading bacteria JT6; Figure 4 The results are shown in the fermentation medium of Bacillus vesiculus JT6 in corn straw fermentation medium (M is the experimental group, CK is the control group). Figure 5 The results are shown in the fermentation medium of Bacillus vesiculus JT6 in rice straw fermentation medium (M is the experimental group, CK is the control group). Detailed Implementation

[0022] The following detailed description of the solutions provided by the present invention, in conjunction with the embodiments, should not be construed as limiting the scope of protection of the present invention.

[0023] The LB culture medium preparation method in this embodiment of the invention is as follows: 5 g yeast extract, 10 g tryptone, 10 g NaCl, 15 g agar, and distilled water to a final volume of 1 L, then sterilized for 15 min.

[0024] The preparation method of CMC-NA culture medium in this embodiment of the invention is as follows: 5 g CMC-Na, 1 g sodium nitrate, 1 g dipotassium hydrogen phosphate, 0.5 g magnesium sulfate, 0.5 g potassium chloride, 0.01 g ferrous sulfate, 15 g agar, and distilled water to a final volume of 1 L, then sterilized for 15 min.

[0025] The method for preparing the inorganic salt culture medium in this embodiment of the invention is as follows: 1 g ammonium nitrate, 0.2 g magnesium sulfate heptahydrate, 1 g dipotassium hydrogen phosphate, 0.1 g calcium chloride dihydrate, 0.15 g potassium chloride, 0.001 g ferric sulfate heptahydrate, 0.001 g zinc sulfate heptahydrate, 0.001 g manganese sulfate, pH adjusted to 7.8. Sterilize at 121℃ for 20 min.

[0026] The preparation method of LB liquid culture medium in this embodiment of the invention is as follows: 5 g yeast extract powder, 10 g tryptone, 10 g NaCl, distilled water to a final volume of 1 L, and sterilized for 15 min.

[0027] The preparation method of the corn stalk fermentation culture medium in this embodiment of the invention is as follows: 0.5 g of corn stalks, 0.4605 g of inorganic salt culture medium, 100 mL of distilled water, sterilized for 15 min.

[0028] The method for preparing the rice straw fermentation culture medium in this embodiment of the invention is as follows: 0.5 g of rice straw, 0.4605 g of inorganic salt culture medium, 100 mL of distilled water, sterilized for 15 min.

[0029] The preparation method of the liquid enzyme-producing culture medium in this embodiment of the invention is as follows: 10 g of CMC-Na, 1 g of dipotassium hydrogen phosphate, 0.5 g of magnesium sulfate heptahydrate, 2 g of ammonium sulfate, 2.5 g of sodium chloride, 2.5 g of yeast extract, and 5 g of peptone are brought to a final volume of 1 L, pH = 7.0, and sterilized at 121°C for 15 min.

[0030] Example 1

[0031] A 10 g sample of saline-alkali soil collected from Qian'an County, Songyuan City, Jilin Province was spread onto LB agar using a gradient dilution method with different pH concentrations. After colonies grew (pH 9.0), single colonies were picked, with each numbered sample being repeated three times. The samples were incubated upside down in a 30℃ incubator. Single colonies were then streaked onto plates. The purified strain was preserved in glycerol. The condition of this strain after 2 days of incubation on LB solid medium at 38℃ is shown in the figure below. Figure 1 As shown.

[0032] Example 2

[0033] Initial screening of cellulose-degrading bacteria

[0034] The isolated single colonies were inoculated into cellulose Congo red (CMC-NA) medium and cultured at 30°C for 3 days. During the culture period, the morphological characteristics of the colonies were observed and strains that formed clear zones on the Congo red plates were screened.

[0035] A strain with cellulose degradation ability was obtained through screening and named JT6. The Congo red staining effect is as follows: Figure 2 As shown.

[0036] Example 3

[0037] Quantitative detection of cellulase activity

[0038] Enzyme activity assays were performed by Jiangsu Enzyme Immunization Industry Co., Ltd. The experiments used filter paper enzyme (FPA) activity kits, endopeptidase (CL) activity kits, exopeptidase (CBH) activity kits, β-glucosidase (β-GC) activity kits, and hemicellulase (ACX) activity kits to determine the activity of the relevant degrading enzymes. Three replicates were performed for each group.

[0039] (1) Preparation of crude cellulase solution: The isolated and purified strain was inoculated into LB liquid medium for activation and cultured at 28℃ and 180 rpm for 2 days. The OD of the bacterial solution was adjusted. 600 To ensure consistency, 5 mL of bacterial culture was inoculated into 100 mL of liquid enzyme-producing medium and cultured at 28°C and 180 rpm for 1 day.

[0040] (2) Cellulase activity assay

[0041] Determination of filter paper enzyme activity (FPA): Take two EP tubes, one as a blank and the other as the test tube. Add 100 μL of the test bacterial solution, one filter paper strip, and 800 μL of acetate-sodium acetate buffer to the test tube; add 100 μL of inactivated bacterial solution, one filter paper strip, and 800 μL of acetate-sodium acetate buffer to the blank tube. Preheat the tubes to 50℃ for 60 min. Add 400 μL of 3,5-dinitrosalicylic acid (DNS) reagent to each tube, mix well, and incubate at 95℃ for 5 min. After cooling, add 400 μL of distilled water to each tube and mix well. Transfer 200 μL to a 96-well plate and read the absorbance value A at 540 nm. ΔA = Atest tube - Ablank tube.

[0042] Assay for endo-β-1,4-glucanase (CL): Take two EP tubes, one as a blank tube and the other as the test tube. Add 0.5 mL of the test bacterial culture and 1 mL of sodium carboxymethyl cellulose solution to the test tube and 0.5 mL of the test bacterial culture and 1 mL of acetate-sodium acetate buffer to the blank tube, respectively. Mix thoroughly and incubate at 40 °C for 24 h. Centrifuge at 12,000 rpm at 25 °C for 10 min, and set aside the supernatant. Take 200 μL of the supernatant from each tube and add 100 μL of DNS reagent to each. The remaining steps are the same as for FPA assay.

[0043] Assay for exo-β-1,4-glucanase (CBH) activity: Three EP tubes were used: one as a blank tube, one as a test tube, and one as a control. 0.1 mL of bacterial culture, 750 μL of sodium acetate buffer, and 50 μL of p-nitrophenyl-β-D-cellobiose solution were added to the test tube; 0.1 mL of bacterial culture and 800 μL of sodium acetate buffer were added to the control tube; and 750 μL of sodium acetate buffer and 50 μL of p-nitrophenyl-β-D-cellobiose solution were added to the blank tube. After thorough mixing and incubation at 37°C for 2 h, 200 μL of sodium carbonate solution was added to each tube, and the mixture was mixed. The tubes were centrifuged at 8000 rpm for 5 min, and 200 μL of the supernatant was transferred to a 96-well plate. The absorbance value A was read at 405 nm. ΔA = Atest tube - Acontrol tube - Ablank tube.

[0044] Assay for β-glucosidase (β-GC): Take three EP tubes, one as a blank tube, one as a test tube, and one as a control. Add 0.05 mL of the test bacterial culture, 150 μL of 4-nitrophenyl-β-D-glucopyranoside, and 300 μL of citrate-phosphate buffer to the test tube; add 0.05 mL of the test bacterial culture, 150 μL of distilled water, and 300 μL of citrate-phosphate buffer to the control tube; add 150 μL of 4-nitrophenyl-β-D-glucopyranoside and 300 μL of citrate-phosphate buffer to the blank tube. Mix thoroughly, shake at 37℃ for 1 h, add 350 μL of sodium carbonate solution to each tube, mix well, centrifuge at 12000 rpm for 10 min, and transfer 200 μL of the supernatant to a 96-well plate. Read the absorbance value A at 405 nm. ΔA = Atest tube - Acontrol tube - Ablank tube.

[0045] Assay for hemicellulase (ACX) activity: Take two EP tubes, one as a control tube and the other as the test tube. Add 0.3 mL of the test bacterial culture, 600 μL of acetate-sodium acetate buffer, 300 μL of xylan and sodium hydroxide mixed solution to the test tube. Add 0.3 mL of the test bacterial culture and 900 μL of acetate-sodium acetate buffer to the control tube. Mix thoroughly and incubate at 40℃ for 6 h. Centrifuge at 12000 rpm, 25℃ for 10 min, and set aside the supernatant. Take 40 μL of the supernatant and add 200 μL of a mixed solution of 3,5-dinitrosalicylic acid, sodium hydroxide, potassium sodium tartrate, phenol, and sodium bisulfate to each. Incubate in a water bath at 100℃ for 5 min. After cooling, add 800 μL of distilled water to each tube and mix well. If turbid, centrifuge at 8000 rpm at room temperature for 5 min. Take 200 μL into a 96-well plate and read the absorbance value A at 540 nm. ΔA = A test tube - A control tube.

[0046] (3) Construction of enzyme activity standard curve

[0047] Filter paper enzyme (FPA) activity standard curve preparation: Weigh glucose and distilled water to prepare glucose standard dilutions at concentrations of 0 mg / mL, 0.6 mg / mL, 1.2 mg / mL, 1.8 mg / mL, 2.4 mg / mL, and 3 mg / mL. Add 100 μL of glucose dilution, 400 μL of DNS reagent, and 800 μL of acetate-sodium acetate buffer to the standard tubes. Add 100 μL of distilled water, 400 μL of DNS reagent, and 800 μL of acetate-sodium acetate buffer to the blank tubes. Mix well and incubate at 100℃ for 5 min. After cooling, add 400 μL of distilled water to each well and mix well. Transfer 200 μL to a 96-well plate and read the absorbance value A at 540 nm. ΔA = Astandard tube - Ablank tube. Plot the standard curve.

[0048] Unit definition: One enzyme activity unit is defined as the amount of enzyme required to decompose filter paper to produce 1 μmol of glucose per minute per milliliter of bacterial culture at 50℃.

[0049] FPA activity (μmol / min / mL) = [(ΔA + 0.0167) ÷ 3.7098] ÷ V ÷ T × D ÷ 10.8

[0050] =2.7×(ΔA+0.0167)×D.

[0051] V is the volume of sample added to the reaction system; T is the reaction time; D is the dilution factor; Plotting a standard curve for endo-β-1,4-glucanase (CL) activity: Weigh glucose and dissolve it in distilled water to prepare glucose standard dilutions at concentrations of 0 mg / mL, 0.1 mg / mL, 0.2 mg / mL, 0.3 mg / mL, 0.4 mg / mL, and 0.5 mg / mL. Add 200 μL of glucose standard dilution and 100 μL of DNS reagent to the standard tube. Add 200 μL of distilled water and 100 μL of DNS reagent to the blank tube. Mix well and incubate at 95°C for 5 min. After cooling, transfer 200 μL to a 96-well plate and read the absorbance value A at 540 nm. ΔA = Astandard tube - Ablank tube. Plot the standard curve.

[0052] Unit definition: One unit of enzyme activity is defined as the production of 1 μg of reducing sugar per milliliter of bacterial culture per minute.

[0053] CL activity (μg / min / ml) = [(ΔA + 0.0555) ÷ 0.0133] ÷ V ÷ T ÷ 60

[0054] =25.0633×(ΔA+0.0555).

[0055] V is the volume of sample added to the reaction system; T is the reaction time.

[0056] Standard curve plotting for exo-β-1,4-glucanase (CBH) activity: PNP (p-nitrophenol) was dissolved in distilled water and sonicated in EP tubes to obtain a PNP stock solution concentration of 10 μmol / mL. Distilled water was added to the PNP stock solution to prepare standard dilutions at concentrations of 0 mg / mL, 0.4 mg / mL, 0.8 mg / mL, 1.2 mg / mL, 1.6 mg / mL, and 2.0 mg / mL. 50 μL of PNP standard dilution, 750 μL of sodium acetate buffer, and 200 μL of sodium carbonate solution were added to the standard tubes; 50 μL of distilled water, 750 μL of sodium acetate buffer, and 200 μL of sodium carbonate solution were added to the blank tubes. All were mixed, and 200 μL was transferred to a 96-well plate. The absorbance value A was read at 540 nm. ΔA = Astandard tube - Ablank tube.

[0057] Unit definition: One unit of enzyme activity is defined as the production of 1 nmol of p-nitrophenol (PNP) per minute per milliliter of bacterial culture.

[0058] CBH activity (nmol / min / ml) = [(ΔA + 0.0094) ÷ 0.0598] ÷ V ÷ T × D ÷ 60

[0059] =11.1483×(ΔA+0.0094).

[0060] V is the volume of sample added to the reaction system; T is the reaction time; D is the dilution factor.

[0061] β-Glucosidase (β-GC) Enzyme Activity Standard Curve Construction: PNP (p-nitrophenol) was dissolved in distilled water and sonicated in EP tubes to obtain a PNP stock solution concentration of 1 mg / mL. The PNP stock solution was then diluted with distilled water to prepare standard dilutions at concentrations of 0 mg / mL, 0.1 mg / mL, 0.2 mg / mL, 0.3 mg / mL, 0.4 mg / mL, and 0.5 mg / mL. 20 μL of PNP dilution solution, 130 μL of distilled water, 300 μL of citrate-phosphate buffer, and 350 μL of sodium carbonate solution were added to the standard tubes. 150 μL of distilled water, 300 μL of citrate-phosphate buffer, and 350 μL of sodium carbonate solution were added to the blank tubes. After mixing, 200 μL of the solution was transferred to a 96-well plate, and the absorbance value (A) was read at 405 nm. The result was ΔA = Astandard tube - Ablank tube. A standard curve was then plotted.

[0062] Unit definition: One unit of enzyme activity is defined as the production of 1 nmol of p-nitrophenol (PNP) per minute per milliliter of bacterial culture.

[0063] β-GC activity (nmol / min / ml) = [(ΔA + 0.0146) ÷ 0.0289] ÷ V ÷ T × D

[0064] =115.34×(ΔA+0.0.0146)×D.

[0065] V is the volume of sample added to the reaction system; T is the reaction time; D is the dilution factor.

[0066] Standard curve preparation for hemicellulase (ACX) activity: D-xylose and distilled water were added to EP tubes to prepare standard dilutions at concentrations of 0 mg / mL, 1 mg / mL, 2 mg / mL, 3 mg / mL, 4 mg / mL, and 5 mg / mL. 40 μL of D-xylose dilution and 200 μL of a mixed solution of 3,5-dinitrosalicylic acid, sodium hydroxide, potassium sodium tartrate, phenol, and sodium bisulfate were added to the standard tubes. 40 μL of distilled water and 200 μL of a mixed solution of 3,5-dinitrosalicylic acid, sodium hydroxide, potassium sodium tartrate, phenol, and sodium bisulfate were added to the blank tubes. The mixture was thoroughly mixed and incubated in a boiling water bath at 100°C for 5 min. After cooling, 800 μL of distilled water was added to each tube and the mixture was thoroughly mixed. If turbidity was observed, the tubes were centrifuged at 8000 rpm for 5 min at room temperature. Take 200 μL into a 96-well plate and read the absorbance value A at 540 nm. ΔA = A standard tube - A blank tube. Plot a standard curve.

[0067] Unit definition: The amount of enzyme required to break down xylan to produce 1 nmol of xylose per minute per milliliter of bacterial culture is defined as one enzyme activity unit.

[0068] ACX activity (nmol / min / mL) = [(△A + 0.0248) ÷ 2.3454 × 10 3 ]÷V÷T×D

[0069] =142.1×(△A+0.248)×D.

[0070] T is the reaction time; D is the dilution factor; V is the volume of sample added to the reaction system.

[0071] The filter paper enzyme (FPA) activity of the cellulose-degrading bacterium JT6 was measured to be 23.98 U / mL, the endopeptidase (CL) activity was 1.12 U / mL, the exopeptidase (CBH) activity was 0.40 U / mL, the β-glucosidase (β-GC) activity was 1.45 U / mL, and the hemicellulose (ACX) activity was 0.066 U / mL.

[0072] Example 4

[0073] Identification of cellulose-degrading bacteria JT6

[0074] Genetic DNA was extracted from the bacterial strain using a kit. PCR amplification was performed using universal primers 27F (5'-AGAGTTTGATCCTGGCTCAG-3' SEQ ID NO.1) and 1492R (5'-TACGGYTACCTTGTTACGACT-3' SEQ ID NO.2) for bacterial 16S rDNA. The PCR reaction system consisted of a 20 µL reaction mixture containing 1× GC buffer I (TAKARA) and 2.5 mM MgSO4. 2+ The PCR amplification products were prepared using 0.2 mM dNTPs, 0.2 µM of each primer, 1 U HotStarTaq polymerase (TAKARA), and 1 µL template DNA. The cycling program was as follows: 95℃ pre-denaturation for 2 min; 11 cycles (94℃ for 20 s, 64℃~0.5℃ / cycle for 40 s, 72℃ for 90 s); 24 cycles (94℃ for 20 s, 58℃ for 30 s, 72℃ for 90 s); 72℃ extension for 2 min; and constant temperature at 4℃. The PCR amplification products were sequenced. The sequence of the obtained 16S rDNA is shown in SEQ ID NO.3.

[0075] SEQ ID NO.3:

[0076] Sequencing results were submitted to the NCBI database for BLAST homology analysis, followed by sequence alignment and phylogenetic tree construction using MEGA 12.0 software. BLAST alignment analysis of the 16S rDNA sequence of the test strain obtained by PCR in the database showed that this strain is similar to *Bacillus belye*. (Bacillus velezensis) They share high homology. Phylogenetic analysis of the 16S rDNA gene shows that the cellulose-degrading bacterium JT6 is similar to Bacillus belesiensis. (Bacillus velezensis) In the same branch (such as) Figure 3 As shown), strain JT6 was classified as Bacillus belye. (Bacillus velezensis) Bacterium genus. Bacillus belye ( Bacillus velezensis JT6 is deposited at the China General Microbiological Culture Collection Center (CGMCC), Institute of Microbiology, Chinese Academy of Sciences, No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing, on December 5, 2025, with accession number CGMCC No. 36918.

[0077] Example 5

[0078] Straw degradation rate

[0079] To verify the cellulose degradation ability of the strain, an indoor liquid fermentation culture method was used, with corn straw and rice straw as research objects, to conduct straw degradation experiments. Corn straw and rice straw were washed under running tap water, dried in an 80℃ oven, cut into 3 cm pieces, and fermentation medium was prepared. Straw strain JT6 was inoculated into LB liquid medium and cultured on a shaker at 10℃ for 3 days to prepare the bacterial solution. Experimental groups: 1 mL of bacterial solution was added to an Erlenmeyer flask containing straw fermentation culture medium (corn straw fermentation medium or rice straw fermentation medium), and the flask was incubated at 30℃ and 180 rpm in a constant temperature incubator. A blank control (CK) was set up with an equal volume of sterilized LB liquid medium added to the straw fermentation solution. Each treatment was repeated three times. The culture time was 45 days. The straw in the Erlenmeyer flasks was collected, rinsed with distilled water, and dried in a drying oven to constant weight. The dry weight of the straw was weighed, and the straw degradation rate was determined. The result was the average of three replicates.

[0080] The formula for calculating the straw degradation rate (η) is: η = (M0 - M) / M0 × 100%

[0081] M represents the dry weight of straw after degradation in the experimental group; M0 represents the dry weight of straw after degradation in the control group; and η represents the straw degradation rate.

[0082] The results of straw degradation rate are as follows Figures 4 - 5As shown, after 45 days of fermentation, the degradation rate of Bacillus vesiculosus JT6 inoculated into corn straw fermentation medium was 48.8%; after 45 days of fermentation in rice straw fermentation medium, the degradation rate was 24.92%.

[0083] As shown in the above embodiments, this invention provides a *Bacillus belyssus* JT6 strain, which exhibits cellulose degradation activity with filter paper enzyme (FPA) activity of 23.98 U / mL, endo-β-1,4-glucanase (CL) activity of 1.12 U / mL, exo-β-1,4-glucanase (CBH) activity of 0.40 U / mL, β-glucosidase (β-GC) activity of 1.45 U / mL, and hemicellulose (ACX) activity of 0.066 U / mL. The degradation rate for corn straw is 48.8%, and the degradation rate for rice straw is 24.92%. Using this strain for rapid decomposition of straw during returning it to the field is safe for humans and animals, and causes no environmental pollution, demonstrating promising development and application prospects.

[0084] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A salt-tolerant Bacillus belye strain ( Bacillus velezensis JT6, characterized in that, It is deposited at the China General Microbiological Culture Collection Center, Institute of Microbiology, Chinese Academy of Sciences, No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing, on December 5, 2025, with accession number CGMCC No. 36918.

2. The Bacillus belesiensis as described in claim 1 ( Bacillus velezensis Application of JT6 in the preparation of products with filter paper enzyme activity.

3. The Bacillus belesiensis as described in claim 1 ( Bacillus velezensis Application of JT6 in the preparation of products with endo-β-1,4-glucanase activity.

4. The Bacillus belesiensis as described in claim 1 ( Bacillus velezensis Application of JT6 in the preparation of products with exo-β-1,4-glucanase activity.

5. The Bacillus belesiensis as described in claim 1 ( Bacillus velezensis Application of JT6 in the preparation of products with β-glucosidase activity.

6. The Bacillus belesiensis as described in claim 1 ( Bacillus velezensis Application of JT6 in the preparation of products with hemicellulase activity.

7. The Bacillus belesiensis as described in claim 1 ( Bacillus velezensis Application of JT6 in the preparation of products that combine filter paper enzyme activity, endo-β-1,4-glucanase activity, exo-β-1,4-glucanase activity, β-glucosidase activity and hemicellulase activity.

8. The Bacillus belesiensis as described in claim 1 ( Bacillus velezensis Application of JT6 in the degradation of cellulose.

9. The Bacillus belesiensis as described in claim 1 ( Bacillus velezensis JT6 has applications in both degrading crop straw and improving saline-alkali soil, wherein the straw is corn straw and / or wheat straw.

10. A method for degrading crop straw, characterized in that, The steps include: mixing crop straw with the Bacillus berleis described in claim 1 (…). Bacillus velezensis JT6 mixed fermentation.

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