A strain of Bacillus parashortia ABX1 and its application

Abstract

This invention discloses a strain of *Bacillus parabrachium* ABX1 and its applications, belonging to the field of beneficial microbial technology. The *Bacillus parabrachium* ABX1 provided by this invention is a Gram-positive bacterium isolated from the intestinal fluid of *Bombyx mori*. On CMC-Na solid medium, the ratio of the diameter of the hydrolysis zone to the colony diameter can reach 11. Enzyme activity identification results show that the filter paper enzyme activity of *Bacillus parabrachium* ABX1 is as high as 109.79 U·mL. ‑1 The exo-β-glucanase activity was 107.59 U·mL. ‑1 The cellulase activity reached 107.37 U·mL ‑1 It exhibits excellent cellulose and / or crystalline cellulose degradation capabilities; it is easy to use and has a wide range of enzyme production conditions, showing excellent enzyme activity at pH 5–10 and 25–50℃; the enzyme production time is short, with high enzyme yield achieved in just 12 hours, and there is no significant adverse effect on enzyme yield with prolonged reaction time; it is highly safe to use and has great application prospects in areas such as oak garden waste branch treatment, improvement of oak silkworm digestibility, industrial degradation of cellulose, and improvement of soil fertility.

Description

Technical Field

[0001] This invention relates to the field of beneficial microbial technology, and in particular to a strain of Bacillus parashortiae ABX1 and its applications. Background Technology

[0002] Tussah silkworm ( Antheraea pernyi The tussah silkworm (Saturnia tussah) is a silk-secreting insect belonging to the family Saturniidae and the genus Saturnia, feeding on oak leaves. In its main production area, Northeast China, the tussah silkworm can reproduce two generations a year: spring silkworms from April to June and autumn silkworms from July to September, overwintering as pupae. Tussah silkworm pupae are rich in protein and, as an edible insect, have a salty and pungent taste, believed to have health benefits, including strengthening the body, improving mental state, and invigorating the kidneys. They are suitable for patients with arteriosclerosis, cirrhosis, coronary heart disease, and hypertension. Tussah silk possesses high tensile strength, acid and alkali resistance, heat resistance, insulation, breathability, and moisture absorption, making it an important raw material for the textile, chemical, power, and defense industries. Various extended products have been developed from tussah silkworms, such as tussah silkworm pupa oil, protein powder, tussah silkworm moth wine, and tussah silkworm pupa cordyceps. Tussah silkworm eggs can be used to make Trichogramma chilonis control agents for corn borers, and tussah silkworm pupae can be used in biological control applications such as controlling the fall webworm. The maintenance of oak plantations and the healthy breeding of oak silkworms are important prerequisites for the healthy development of the oak silkworm industry.

[0003] The known functions of cellulase mainly include: 1) In the textile and paper industries, such as processing natural fibers like cotton and linen to make them softer and smoother, and recycling waste textiles; improving paper strength and quality, making it more flexible and less prone to tearing; 2) In the pharmaceutical field, promoting the proliferation of beneficial bacteria in the gut, inhibiting the growth of harmful bacteria, regulating the gut microbiota, and maintaining gut health; as an important hypoglycemic drug, it is used to treat diabetes and related diseases; it also has cholesterol-lowering, anti-inflammatory, and antibacterial effects; by mechanically stimulating intestinal peristalsis, it can prevent and treat constipation; by absorbing water and swelling, it increases satiety, reduces food intake, and helps prevent obesity; 3) In the food industry, it is used for food improvement and processing, improving the clarity and taste of fruit juices, processing food packaging materials, and extending the shelf life of food; 4) In the feed industry, adding cellulase can improve the digestibility and utilization of cellulose in feed, promoting animal growth. Summary of the Invention

[0004] The purpose of this invention is to provide a strain of Bacillus parabrachii ABX1 and its applications. The provided Bacillus parabrachii ABX1 is a new strain with excellent cellulose degradation ability and cellulase production ability, and has great application prospects in many fields such as industry, food, medicine, feed and soil fertilizer.

[0005] To achieve the above objectives, the present invention provides a strain of Bacillus parabriquets ABX1, whose Latin name is... Brevibacillus parabrevisABX1 was deposited on December 5, 2024, at the China General Microbiological Culture Collection Center (CGMCC), located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, with accession number CGMCCNo. 32929.

[0006] The application of Bacillus parabrachii ABX1 as described above in tussah silkworm farming increases the abundance of Bacillus parabrachii ABX1 in the silkworm's body by spraying Bacillus parabrachii ABX1 on the leaves eaten by the silkworm or by other methods of introducing Bacillus parabrachii ABX1 into the silkworm's body, thereby improving the silkworm's digestibility and utilization of the leaves.

[0007] The application of a strain of Bacillus parabrachii ABX1 as described above in the preparation of cellulase, which includes filter paper enzyme, exo-β-glucanase and cellulase.

[0008] The application of Bacillus parabrachii ABX1 as described above in tussah silkworm farming involves inoculating the leaves consumed by tussah silkworms with Bacillus parabrachii ABX1, thereby increasing the abundance of Bacillus parabrachii ABX1 in the intestinal microbiota of tussah silkworms and improving the digestibility and utilization rate of the leaves by tussah silkworms.

[0009] The application of Bacillus parabrittlesis ABX1 as described above in the preparation of pharmaceuticals, the effects of which are to promote the proliferation of probiotics in the intestine and maintain intestinal health; and / or to reduce inflammation and kill bacteria; and / or to lower cholesterol; and / or to maintain stable blood sugar; and / or to treat constipation; and / or to lose weight.

[0010] Application of Bacillus parashortiae ABX1 as described above in the textile industry.

[0011] Application of Bacillus parashortiae ABX1 as described above in the paper industry.

[0012] Application of Bacillus parashortiae ABX1 as described above in the preparation of animal feed.

[0013] The application of Bacillus parashortiae ABX1 as described above in the preparation of soil fertilizer, which is humus obtained by degrading plant branches and / or leaves.

[0014] The application of Bacillus parabrachium ABX1, as described above, in the treatment of agricultural waste, which is cellulose-rich agricultural waste, including straw, stems, branches, and leaves.

[0015] Therefore, the specific technical effects of the *Bacillus parashortia* ABX1 strain and its application provided by this invention are as follows:

[0016] (1) The Bacillus parashortia ABX1 provided by the present invention is a Gram-positive bacterium isolated from the intestinal fluid of silkworm. The colonies grown on LB solid plates are round, white, with neat edges, convex shape, and smooth and moist surface.

[0017] (2) The *Bacillus parabrachii* ABX1 provided by this invention can form hydrolysis zones when grown on CMC-Na solid medium, and the ratio of the diameter of the hydrolysis zone to the diameter of the colony can reach 11; the enzyme activity identification results show that the filter paper enzyme activity of *Bacillus parabrachii* ABX1 is as high as 109.79 U·mL. -1 The exo-β-glucanase activity was 107.59 U·mL. -1 The cellulase activity reached 107.37 U·mL -1 It has excellent degradation ability of cellulose and / or crystalline cellulose;

[0018] (3) The Bacillus parashortia ABX1 provided by the present invention is easy to use and has a wide range of enzyme production conditions. It has excellent enzyme production activity under pH 5~10 and 25~50℃ conditions. The enzyme production time is short, and the enzyme yield is high after 12h of reaction. Moreover, the enzyme yield is not significantly affected by the extension of reaction time.

[0019] (4) Tussah silkworm is an insect food with no toxic side effects on the human body. The parabrachiobacter parasporus ABX1 isolated from the intestinal fluid of tussah silkworm has high safety and has great application prospects in the fields of medicine, papermaking, food, feed and soil fertilizer.

[0020] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 These are photographs of Congo Red identification medium plates from Example 1 of the present invention; wherein A represents strains B-1 to B-4; B represents strains B-5 to B-8; C represents strains B-9 to B-12; and D represents strains B-13 to B-16.

[0023] Figure 2 These are photographs of the experimental results of dynamic enzymatic hydrolysis of filter paper strips in Example 1 of the present invention; where A is before dynamic enzymatic hydrolysis; and B is after dynamic enzymatic hydrolysis.

[0024] Figure 3These are electrophoresis images of the colony PCR products in Example 2 of this invention;

[0025] Figure 4 This is a phylogenetic tree of strain ABX-1 based on the 16S rRNA sequence in Example 2 of this invention;

[0026] Figure 5 This is an LB plate photograph of the purified ABX-1 strain cultured for 3 days in Example 2 of this invention;

[0027] Figure 6 These are the results of the investigation on the effect of inoculum amount on enzyme production in Example 3 of the present invention; where A is the effect of inoculum amount on filter paper enzyme activity; B is the effect of inoculum amount on exo-β-glucanase activity; and C is the effect of inoculum amount on cellulase activity.

[0028] Figure 7 The results of the study on the effect of pH on enzyme production in Example 3 of the present invention are as follows: A is the effect of inoculum amount on filter paper enzyme activity; B is the effect of inoculum amount on exo-β-glucanase activity; and C is the effect of inoculum amount on cellulase activity.

[0029] Figure 8 The results of the study on the effect of culture temperature on enzyme production in Example 3 of this invention are as follows: A represents the effect of inoculum size on filter paper enzyme activity; B represents the effect of inoculum size on exo-β-glucanase activity; and C represents the effect of inoculum size on cellulase activity.

[0030] Figure 9 The results of the study on the effect of culture time on enzyme production in Example 3 of this invention are as follows: A is the effect of inoculum size on filter paper enzyme activity; B is the effect of inoculum size on exo-β-glucanase activity; and C is the effect of inoculum size on cellulase activity.

[0031] Figure 10 This is in embodiment 4 of the present invention. Brevibacillus parabrevis Results of an investigation into the effect of strain ABX1 on the cellulose content in oak leaves.

[0032] Bacillus parabrittlesis ABX1 was deposited on December 5, 2024, at the China General Microbiological Culture Collection Center (CGMCC), located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, with accession number CGMCC No. 32929. Detailed Implementation

[0033] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0034] To make the objectives, technical solutions, and advantages of this application clearer, more thorough, and more complete, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. The following detailed descriptions are all descriptions of embodiments, intended to provide further detailed explanation of the present invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0035] The instruments, equipment, reagents and materials used in the embodiments were all obtained through commercial means; the methods and steps not described in detail in the embodiments are all conventional techniques in the art.

[0036] The culture medium formulation (per liter) used in the examples is as follows:

[0037] LB medium: 10.0g tryptone, 5.0g yeast extract, 10.0g sodium chloride, 15.0g agar added to solid medium, no agar added to liquid medium, distilled water to 1000mL;

[0038] CMC-Na solid culture medium: 1.0g potassium dihydrogen phosphate, 1.0g ammonium nitrate, 10.0g sodium chloride, 10.0g peptone, 0.5g magnesium sulfate, 10.0g CMC-Na, 20.0g agar, pH 7.0~7.5, distilled water to a final volume of 1000mL;

[0039] Congo red identification medium: 1.0 g potassium dihydrogen phosphate, 2.0 g ammonium sulfate, 10.0 g sodium chloride, 0.4 g Congo red, 0.5 g magnesium sulfate, 10.0 g CMC-Na, 20.0 g agar, pH 7.0~7.5, distilled water to a final volume of 1000 mL;

[0040] Liquid fermentation enzyme production medium: 4.0g potassium dihydrogen phosphate, 2.0g ammonium sulfate, 0.3g sodium chloride, 0.3g magnesium sulfate, 10.0g sodium carboxymethyl cellulose, 0.5g yeast extract, 3.0g peptone, and distilled water to a final volume of 1000mL;

[0041] Culture medium for bacterial culture: 5.0g peptone, 0.5g yeast powder, 10.0g beef extract, 5.0g sodium chloride, 5.0g glucose, and distilled water to a final volume of 1000mL;

[0042] Liquid filter paper decomposition culture medium: 2.0g potassium dihydrogen phosphate, 0.3g magnesium sulfate, 0.01g sodium chloride, 0.1g ferric chloride, 2.5g sodium nitrate, 0.1g calcium chloride, 1.0g dipotassium hydrogen phosphate, 1.5×2.0cm filter paper strips, and distilled water to a final volume of 1000mL;

[0043] Fermentation medium: 4.0g potassium dihydrogen phosphate, 2.0g ammonium sulfate, 0.3g sodium chloride, 0.4g Congo red, 0.3g magnesium sulfate, 5.0g oak leaves, 20.0g agar, pH 7.0~7.5, distilled water to a final volume of 1000mL.

[0044] Example 1

[0045] The ABX-1 strain with cellulose-degrading ability was obtained as follows:

[0046] (1) Take 5th instar silkworms, dissect them under sterile conditions, obtain intestinal fluid, collect it into a 1.5mL sterile centrifuge tube, weigh 0.1g of intestinal fluid into the centrifuge tube, add 0.1mL of sterile water and shake well. Streak the obtained mixture on a solid LB medium plate, incubate at 37℃ overnight, pick out the single colonies at the streaked part of the medium and place them on a new LB medium plate, repeating until pure colonies are obtained.

[0047] In a clean bench, bacteria were inoculated onto CMC-Na solid medium using a sterile inoculation loop and incubated statically at 37°C for 3 days. Colonies that grew were then streaked onto CMC-Na solid plates and incubated at 37°C. Once the colonies had grown, they were inoculated onto fresh CMC-Na solid medium and incubated for three consecutive days. Finally, single colonies that could grow on CMC-Na solid medium were selected, streaked onto LB agar plates, and stored at 4°C.

[0048] (2) The ability of the strain to degrade cellulose was investigated using the hydrolysis zone method. Single colonies grown on LB plates stored at 4℃ were spot-inoculated onto the center of filter paper discs in a clean bench, and then placed on Congo red identification medium plates. Four spot-inoculated filter paper discs were placed on each plate, and the plates were incubated at 37℃ for 3 days. The hydrolysis zones of the strains were observed, photographed, and the diameter of the hydrolysis zones (unit D / cm) and the diameter of the colonies (unit d / cm) were measured and recorded. The D / d ratio was calculated, and the measurements were performed using vernier calipers.

[0049] Generally, a higher D / d ratio indicates a stronger ability of the strain to degrade cellulose, which can be used to preliminarily determine the activity of the cellulase produced by the strain. Sixteen strains were initially screened and numbered B-1 to B-16. A photograph of a replicate culture medium is shown below. Figure 1 As shown in Table 1, the measurement and calculation results show that strain B-1 has the largest D / d ratio.

[0050] Table 1. Statistical results of hydrolysis zone diameter, colony diameter, and D / d ratio.

[0051]

[0052] (3) Use enzyme activity as an evaluation index to re-screen the strains obtained in the initial screening.

[0053] The 16 strains obtained in (2) were each inoculated into liquid fermentation enzyme-producing medium at an inoculation rate of 3%. Subsequently, the bottle mouths were sealed with sealing film, and the culture environment was set at a temperature of 37℃ and a rotation speed of 150r / min for 48h. After centrifugation at 4℃ and 4500rpm for 10min, the supernatant (crude enzyme extract) was aspirated and enzyme activity was measured using a filter paper enzyme (FPA) kit, an exo-β-glucanase (CBH) kit, and a cellulase (CMC) kit, respectively. Each measurement was performed in triplicate, and the average value of the results was taken.

[0054] Five strains (B-1, B-4, B-5, B-6, and B-8) exhibited relatively high enzyme activities and were renamed ABX1~5 (as shown in Table 2). Among them, strain ABX-1 (formerly strain B-1) showed significantly higher enzyme activities than the other strains, with a filter paper enzyme activity as high as 109.79 U·mL. -1 The exo-β-glucanase activity was 107.59 U·mL. -1 The cellulase activity reached 107.37 U·mL -1 Thus, strain ABX-1 was identified as the selected cellulose-degrading bacterium. After screening, the strain was further isolated and purified using the method in (1). The purified ABX-1 strain was inoculated into a culture medium and stored at 4°C for later use.

[0055] Table 2 Enzyme activity assay results

[0056]

[0057] (4) The crude enzyme extract of strain ABX-1 was inoculated into 100 mL of liquid filter paper degradation medium at a volume ratio of 3% (v / v). Filter paper strips (1×6 cm, quantitative filter paper) were placed in each bottle, and the mixture was incubated at 37℃ with shaking (150 rpm) for dynamic enzymatic hydrolysis. An equal volume of sterile distilled water was used as a blank control. The synergistic degradation efficiency of the cellulase system was evaluated by the filter paper disintegration time and morphological changes (surface corrosion, etc.). This experiment quantitatively analyzed the biotransformation ability of the strain to crystalline cellulose by constructing a standardized enzymatic hydrolysis evaluation model.

[0058] The results are as follows Figure 2 As shown, the culture medium in the blank control group remained clear throughout, and the filter paper remained intact; however, in the experimental group inoculated with the crude enzyme extract of strain ABX-1, the filter paper gradually decomposed into fragments, and the culture medium became significantly turbid. This indicates that strain ABX-1 can degrade cellulose through the secretion of cellulase, demonstrating its potential for biotransformation applications.

[0059] Example 2

[0060] Morphological, physiological and biochemical, and molecular identification of strain ABX1 was performed as follows:

[0061] (1) Using the universal primers 27F (sequence shown in SEQ ID NO.1) and 1492R (sequence shown in SEQ ID NO.2) for bacterial 16S rRNA, colonies of ABX-1 strain were selected as templates for colony PCR amplification. The PCR amplification conditions were: 94℃ pre-denaturation for 10 min; 94℃ denaturation for 30 s, 55℃ annealing for 30 s, 72℃ extension for 1 min, for a total of 35 cycles; the reaction was terminated after 72℃ extension for 10 min. The PCR amplification system was 25 μL, containing 12.5 μL of PCR buffer mix (containing Taq enzyme), 1 μL each of forward and reverse primers, 2 μL of DNA template, and 8.5 μL of ddH2O.

[0062] 2 μL of the PCR product was subjected to agarose gel electrophoresis, and the results are as follows: Figure 3 As shown. The remaining PCR product was sent to Sangon Biotech (Shanghai) Co., Ltd. for sequencing. The sequencing result, as shown in SEQ ID NO.3, was 1432 bp, consistent with the electrophoresis result. The obtained sequencing sequence was compared for homology on NCBI, and phylogenetic analysis with other homologous species was performed as follows. Figure 4 As shown, the results indicate that strain ABX-1 is similar to previously identified Bacillus strains (…). Bacillus The highest homology was observed, with a homology of 99.79%. The obtained strain ABX-1 is *Bacillus parabrittleis*, a member of the genus *Bacillus*. Brevibacillus parabrevis ), named Bacillus parashortia ABX1 ( Brevibacillus parabrevis ABX1).

[0063] SEQ ID NO.1: TACGGYTACCTTGTTACGACTT

[0064] SEQ ID NO.2: AGAGTTTGATCMTGGCTCAG

[0065] SEQ ID NO.3:

[0066]

[0067] (2) The purified ABX-1 strain from (3) of Example 1 was inoculated onto LB plates and cultured for 3 days. The photograph is shown below. Figure 5 As shown, the colonies are round, white, with neat, convex edges and a smooth, moist surface.

[0068] (3) Referencing the physiological and biochemical characteristics of the strains, the strains were identified by referring to the "Handbook of Systematic Identification of Common Bacteria". Brevibacillus parabrevis The ABX1 strain was subjected to Gram staining, methyl red test, VP test, starch hydrolysis test, gelatin liquefaction test, and indole test, and the results are shown in Table 3. Brevibacillus parabrevis ABX1 is a Gram-positive bacterium.

[0069] Table 3. Statistical analysis of Gram staining, methyl red test, VP test, starch hydrolysis test, gelatin liquefaction test, and indole test results.

[0070]

[0071] "+" indicates a positive result; "-" indicates a negative result.

[0072] Example 3

[0073] Investigation Brevibacillus parabrevis The optimal enzyme production conditions for strain ABX1 are as follows:

[0074] (1) Investigate the effect of inoculum size on enzyme production.

[0075] Will Brevibacillus parabrevis ABX1 strain was inoculated into liquid fermentation enzyme-producing medium at inoculum concentrations of 1%, 2%, 3%, 4%, 5%, and 6%, respectively. The flasks were then sealed with sealing film, and the culture environment was set at 37°C and 150 rpm for 48 hours. After centrifugation at 4°C and 4500 rpm for 10 minutes, the supernatant (crude enzyme extract) was aspirated, and enzyme activity was measured using a filter paper enzyme (FPA) kit, an exo-β-glucanase (CBH) kit, and a cellulase (CMC) kit. Each assay was performed in triplicate, and the average value was taken.

[0076] The results are as follows Figure 6 As shown, a 3% inoculum size is the optimal condition for enzyme production. Brevibacillus parabrevis The ABX1 strain exhibited the highest peak values ​​for FPA (filter paper enzyme activity) and CBH (exo-β-glucanase) activities. Enzyme activity decreased slightly at inoculum levels of 4% and 5%, leading to a longer production cycle; when the inoculum level increased to 6%, enzyme activity decreased further.

[0077] (2) Investigate the effect of pH on enzyme production.

[0078] The activities of filter paper enzyme, exo-β-glucanase and cellulase were determined using the method in (1), except that the inoculum amount was 3% and the initial pH of the culture medium was 5, 6, 7, 8, 9 and 10, respectively.

[0079] The results are as follows Figure 7 As shown, when the initial pH of the culture is set to 7, Brevibacillus parabrevis The ABX1 strain exhibited the highest enzyme production activity; however, when the initial culture pH was less than 6 or greater than 9, the enzyme production capacity of the strain decreased significantly.

[0080] (3) Investigate the effect of culture temperature on enzyme production.

[0081] The activities of filter paper enzyme, exo-β-glucanase and cellulase were determined by the method in (1), except that the inoculum amount was 3%, the initial pH of the culture medium was 7, and the culture temperature was 25℃, 30℃, 35℃, 40℃, 45℃ and 50℃ respectively.

[0082] The results are as follows Figure 8 As shown, at a lower temperature (25℃), the bacterial growth rate is relatively slow, and the corresponding enzyme production is also at a lower level; however, when the temperature rises to an excessively high level (45℃), the bacterial cells begin to show signs of aging, and the enzyme production subsequently decreases. Experimental measurements indicate that... Brevibacillus parabrevis The optimal culture temperature for strain ABX1 is 40℃. Under this temperature condition, Brevibacillus parabrevis The ABX1 strain exhibits ideal cell growth activity and enzyme production capacity, providing a suitable environment for efficient cellulase fermentation.

[0083] (4) Investigate the effect of culture time on enzyme production.

[0084] The activities of filter paper enzyme, exo-β-glucanase and cellulase were determined by the method in (1). The inoculum amount was 3%, the initial pH of the culture medium was 7.0, the culture temperature was 37℃, and the culture time was 12h, 24h, 36h, 48h, 60h and 72h, respectively.

[0085] The results are as follows Figure 9 As shown, enzyme activity exhibited a continuous upward trend from 12 to 48 hours, reaching its maximum at 48 hours. However, from 48 hours onwards, enzyme activity began to decline. Analysis suggests that this decrease in enzyme activity is most likely due to the degradation of the enzyme protein by proteases secreted by the bacteria themselves, thus reducing its activity.

[0086] Example 4

[0087] Measurement Brevibacillus parabrevis The effects of strain ABX1 on the cellulose content in oak leaves are detailed below:

[0088] preparation Brevibacillus parabrevis ABX1 bacterial suspension. Pick up the bacterial suspension grown on LB agar plates. Brevibacillus brief A single colony of ABX1 was added to 50 mL of sterile LB broth and incubated at 37°C and 180 rpm on a shaker until OD500 was reached. 595 Once the OD value reaches 1.0, centrifuge at 5000 rpm for 5 min, wash the precipitate three times with 0.9% physiological saline, and then resuspend the bacterial cells in sterile water (OD). 595 After adding 0.5 mL of the culture medium (e.g., 1.0 μL), the culture was inoculated into the fermentation enzyme-producing medium and cultured at 37°C and 180 rpm for 6 days (referred to as the treatment group, ABX-1). The cellulose content was then determined using a cellulose assay kit. The control group (CK) consisted of an equal volume of culture medium without the addition of bacteria.

[0089] The results are as follows Figure 10 As shown, the cellulose content in the treatment group was significantly lower than that in the control group, indicating that strain ABX-1 has outstanding performance in the degradation of cellulose in oak leaves and can effectively promote the decomposition process of cellulose. This characteristic enables the conversion of the cellulose portion of oak resources that was originally difficult to utilize, significantly improving the overall utilization efficiency of oak resources and opening up a new path for the in-depth development and rational application of oak resources.

[0090] Therefore, the *Bacillus parabrachium* ABX1 provided by this invention is a Gram-positive bacterium isolated from the intestinal fluid of *Bombyx mori*. The ratio of the diameter of the hydrolysis zone to the colony diameter on CMC-Na solid medium can reach 11. Enzyme activity identification results show that the filter paper enzyme activity of *Bacillus parabrachium* ABX1 is as high as 109.79 U·mL. -1 The exo-β-glucanase activity was 107.59 U·mL. -1 The cellulase activity reached 107.37 U·mL -1 It has excellent cellulose and / or crystalline cellulose degradation capabilities; it is easy to use and has a wide range of enzyme production conditions, exhibiting excellent enzyme production activity under pH 5-10 and 25-50℃ conditions; the enzyme production time is short, with high enzyme yield achieved in 12 hours of reaction, and there is no significant adverse effect on enzyme yield with prolonged reaction time; it has high safety in use and has great application prospects in the fields of medicine, papermaking, food, feed and soil fertilizer.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A strain of Paenibacillus parvus ABX1, characterized in that: The Latin name is Brevibacillus parabrevis ABX1 was deposited with China General Microbiological Culture Collection Center on December 5, 2024, at an address of No. 1, Beichen West Road, Yard 3, Chaoyang District, Beijing, with a preservation number of CGMCC No. 32929.

2. Use of a strain of Brevibacillus parabrevis ABX1 as claimed in claim 1 for the preparation of a product having filter paper enzyme, exo-beta-glucanase and cellulase activity.

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