CN118146982A - Bacillus and biological agent capable of degrading uric acid and preparation method thereof - Google Patents

Abstract

A bacillus, a biological preparation and a preparation method thereof that can degrade uric acid, wherein the bacillus that can degrade uric acid is bacillus XRK-1 (Bacillus sp. XRK-1), with a deposit number of CCTCC M 20232477, a deposit date of December 6, 2023, and a deposit unit of China Center for Type Culture Collection. The present invention also discloses a microbial preparation produced by fermentation of the bacillus XRK-1 strain and a preparation method thereof. The bacillus XRK-1 that can degrade uric acid is separated from a sunflower disc, has the ability to produce urate oxidase to degrade urea, and the urate oxidase enzyme activity is as high as 0.103U/ml, which can efficiently degrade uric acid in vitro. Bacillus XRK-1 grows rapidly, has strong stress resistance and high biosafety; the microbial preparation obtained by fermentation thereof, and the preparation method of the microbial preparation, the microbial preparation can be used to reduce uric acid, and has a wide range of application prospects.

Description

Bacillus capable of degrading uric acid, biological preparation and preparation method thereof

Technical Field

The present invention relates to the field of microbial technology, and in particular to a bacillus capable of degrading uric acid in vitro, a biological preparation and a preparation method thereof.

Background technique

Hyperuricemia is a disease of abnormal uric acid metabolism. The main causes of the disease include abnormal metabolism of purine substances in the body and the inability to excrete uric acid normally. Due to changes in people's living conditions, the dietary structure has changed significantly. Foods with a high proportion of purine are becoming more and more close to people's daily lives. With the emergence of high-purine dietary habits, the number of patients with hyperuricemia has increased year by year. Hyperuricemia has become the "fourth highest" disease, ranking alongside hypertension, hyperglycemia, and hyperlipidemia. According to statistics, about 10% of hyperuricemia patients will further develop gout.

30% to 40% of human uric acid is excreted from the body through the intestinal tract and bile duct. Uric acid in the intestinal tract comes from blood, liver, food, etc. This part of uric acid can be decomposed by intestinal flora or directly excreted from the body. Uric acid excreted through the intestinal tract can be decomposed into allantoin with high solubility (5 to 10 times that of uric acid) by uricase produced by microorganisms in the large intestine, such as a plant lactobacillus that produces uricase oxidase and inhibits xanthine oxidase and its application disclosed in CN114149947A, wherein the plant lactobacillus (Lactobacillus plantarum) BLCC2-0296 can produce uricase oxidase and has the ability to directly degrade uric acid; it also has the inhibitory activity of xanthine oxidase. Intestinal microorganisms can also assist in lowering uric acid by directly intervening in the absorption of purine components in food, such as the Bacillus coagulans, methods and applications derived from shrimp paste, which have uric acid lowering and antioxidant capabilities. The Bacillus coagulans GH1-1 has strong purine metabolism and xanthine oxidase XOD inhibition capabilities. Some bacteria can degrade nucleosides into purine bases that are relatively more difficult to absorb in the intestines by colonizing in the host intestines, reducing the intestinal absorption of nucleosides, thereby reducing serum uric acid levels.

Most of the existing technologies use probiotics such as Lactobacillus casei, Lactobacillus gasseri and Lactobacillus fermentum to biodegrade adenosine, guanosine, adenylic acid, guanylic acid, adenine and guanine to achieve the purpose of reducing uric acid production. Lactobacillus has incomparable advantages over drug treatment in reducing uric acid synthesis and treating hyperuricemia, such as no adverse drug reactions, no need for additional dietary restrictions, high patient compliance, and relief of inflammation during renal damage. However, lactobacillus has poor stress resistance and is not conducive to preservation, which limits its efficacy in preventing and treating hyperuricemia.

Bacillus has the advantages of broad antibacterial spectrum, rapid growth, strong stress resistance and high biosafety. Therefore, screening out Bacillus that can degrade uric acid has important research significance and application value.

Summary of the invention

The technical problem to be solved by the present invention is: to overcome the deficiencies of the prior art and provide a Bacillus XRK-1 that can produce high urate oxidase and degrade uric acid, as well as a biological preparation fermented by the Bacillus XRK-1. The present invention also optimizes the culture conditions of the Bacillus XRK-1 and the preparation method of the biological preparation.

The technical solution adopted by the present invention to solve the technical problem is:

A bacillus capable of degrading uric acid, wherein the bacillus is Bacillus sp. XRK-1, with a deposit number of CCTCC M 20232477, a CCTCC deposit date of December 6, 2023, and a depository unit of China Center for Type Culture Collection.

1) Morphological observation of strains

The bacillus was isolated from a sunflower disk. The colonies of the bacillus XRK-1 on the plate were white, convex and nearly circular, and were blue-purple under Gram staining, indicating that the strain was a Gram-positive bacterium. The colonies were uniform in shape within the field of view of a microscope, and were short rod-shaped in cell morphology, and were arranged in a single arrangement.

2) Molecular biological identification of strains

The isolated and purified Bacillus strain was subjected to 16S rRNA identification, and the 16S rRNA sequence of the strain was shown in Seq ID NO: 1, and was named Bacillus XRK-1. The measured 16S rRNA sequence was compared with NCBI BLAST, and the highest homology with Bacillus (Bacillaceae gen.sp.) in Genebank was 96.39%. Based on the results of the 16S rRNA gene sequence comparison, a Neighbor-Joining phylogenetic tree (see Figure 4) was constructed with Oceanobacillus halotolerans strain YIM 98839 as an outer branch, and the strain was preliminarily identified as Bacillus (Bacillaceae gen.) XRK-1.

The above-mentioned Bacillus XRK-1 has the ability to produce urate oxidase to degrade uric acid, and can efficiently degrade uric acid in vitro.

In one exemplary embodiment, the activity of urate oxidase produced by the Bacillus XRK-1 is as high as 0.103 U/ml.

A microbial preparation is produced by fermentation of the above-mentioned Bacillus XRK-1 capable of degrading uric acid.

The above-mentioned microbial preparation includes one or more of live Bacillus XRK-1 bacteria, spores, inactivated Bacillus XRK-1 bacteria, metabolites and postbiotics thereof.

A method for preparing a microbial preparation comprises the following steps:

S1. Inoculating the fermentation strain into a fermentation medium for fermentation culture to obtain a fermentation culture of Bacillus; wherein the fermentation strain is obtained by seed culture of Bacillus XRK-1 strain;

S2. Centrifugation is performed on the fermentation culture of Bacillus to harvest bacterial cells and/or spores of Bacillus.

The fermentation medium is composed of the following raw materials: 20 g/L sucrose, 10 g/L yeast extract, 17.1 g/L disodium hydrogen phosphate, 3 g/L potassium dihydrogen phosphate, 0.5 g/L magnesium sulfate, 0.01 g/L anhydrous calcium chloride, 2 g uric acid, distilled water, pH 7.0, and high pressure sterilization at 121° C. for 25 min.

In S1, the fermentation culture temperature is 30-45°C, preferably 37-42°C.

Optionally, S2 of the preparation method further comprises washing the bacterial cells and/or spores of Bacillus with physiological saline to obtain pure bacterial cells and/or spores of Bacillus.

The preparation method of the microbial preparation also includes:

S3. Optionally, the supernatant of the fermentation culture of Bacillus is centrifuged and inactivated at high temperature (121° C., 30 min), centrifuged, and concentrated to obtain metabolites;

S4. Optionally, the fermentation culture of Bacillus is subjected to cell lysis, high temperature inactivation (121° C., 30 min), and concentration to obtain postbiotics containing Bacillus cells and their metabolites;

S5. Freeze-dried powder obtained by freeze-drying one or more of the bacterial cells, spores, metabolites and postbiotics of Bacillus.

The invention discloses an application of a microbial preparation in the preparation of a uric acid-lowering drug.

The beneficial effects of the uric acid-degrading bacillus of the present invention are as follows:

The uric acid-degrading Bacillus XRK-1 of the present invention is separated from sunflower discs, has the ability to produce urate oxidase to degrade uric acid, and the urate oxidase activity is as high as 0.103U/ml, and can efficiently degrade uric acid in vitro. Bacillus XRK-1 grows rapidly, has strong stress resistance and high biological safety.

The invention also discloses a microbial preparation obtained by fermenting Bacillus XRK-1 and a preparation method of the microbial preparation. The microbial preparation can be used for reducing uric acid and has broad application prospects.

Biomaterial Deposit

Bacillus sp. XRK-1 was deposited in the China Center for Type Culture Collection on December 6, 2023, with the deposit number CCTCC M 20232477. The deposit address is: No. 299, Bayi Road, Wuchang District, Wuhan City, Hubei Province, China Center for Type Culture Collection.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a plate diagram of the separation and screening of Bacillus XRK-1 capable of degrading uric acid according to the present invention;

FIG2 is a colony morphology diagram of a uric acid-degrading Bacillus XRK-1 of the present invention;

FIG3 is a diagram showing the results of Gram staining microscopy of a uric acid-degrading Bacillus XRK-1 of the present invention;

FIG4 —A phylogenetic tree of Bacillus XRK-1 capable of degrading uric acid according to the present invention;

FIG5 is a graph showing the biomass-time variation of Bacillus XRK-1 capable of degrading uric acid according to the present invention;

FIG6 is a standard curve diagram for the determination of urate oxidase activity;

FIG. 7 is a comparative diagram of the urate oxidase activity secreted by Bacillus XRK-1, a uric acid-degrading strain of the present invention, under different fermentation media.

Detailed ways

The present invention is further described below in conjunction with the accompanying drawings and embodiments.

the term

The term "bacterial body" as used in the present invention refers to living cells and/or dead cells of bacteria.

The term "spore" in the present invention refers to a dormant body with very strong stress resistance formed by Bacillus under certain conditions.

The term "microbial preparation" used in the present invention refers to various forms of preparations that are made from microorganisms with medical research value, using traditional technology or modern biotechnology, and are used for the prevention (health care), treatment and diagnosis of various physiological symptoms of the human body.

The "water" used in the culture medium or fermentation culture process of the present invention, unless otherwise specified, refers to sterile pure water obtained by filtering through a filter membrane (0.22 μm).

The following is the culture medium involved in the embodiments of the present invention:

Enrichment medium: 17.1 g disodium hydrogen phosphate, 3 g potassium dihydrogen phosphate, 0.5 g magnesium sulfate, 0.01 g anhydrous calcium chloride, 2 g uric acid, 1 L distilled water, pH 7.5, autoclave at 121°C for 25 min.

Uric acid selection medium (liquid): 17.1 g disodium hydrogen phosphate, 3 g potassium dihydrogen phosphate, 0.5 g magnesium sulfate, 0.01 g anhydrous calcium chloride, 2 g uric acid, 1 L distilled water, pH 7.5, high pressure sterilization at 121°C for 25 min.

Uric acid selection medium (plate): 17.1 g disodium hydrogen phosphate, 3 g potassium dihydrogen phosphate, 0.5 g magnesium sulfate, 0.01 g anhydrous calcium chloride, 2 g uric acid, 12 g agar, 1 L distilled water, pH 7.5, high pressure sterilization at 121°C for 25 min.

Example 1

1 to 3 , a Bacillus XRK-1 capable of degrading uric acid, with a deposit number of CCTCC M 20232477, a deposit date of December 6, 2023, and a depository institution of China Center for Type Culture Collection.

1) Isolation of strains

Take 10g of sunflower disc, put it into a non-woven filter bag, inoculate it into 50mL of enrichment medium with uric acid (uric acid content is 2g/L) as the only carbon source, and place it in a constant temperature incubator (30℃, 180r/min) for shaking culture for 3-5 days to prepare for strain screening. Dilute the enriched bacterial solution to ^10-1 / ^10-2 times, and take 100μL of bacterial solution and spread it on the uric acid selection medium (plate), and invert it at 30℃ for 24h-48h, and observe the growth of the colony at any time. After the colony is formed, put the plate upside down in a 4℃ refrigerator, and observe the growth of the colony and the size of the transparent circle at any time during the culture process (whether a transparent circle appears around the colony and the size of the transparent circle can determine whether the strain produces urate oxidase, and the strength of the urate oxidase enzyme activity produced). The transparent circle is shown in Figure 1.

2) Purification of strains

Several single colonies were picked from the above plate, and the selected single colonies were morphologically and transparently zoned as much as possible, and the selected single colonies were inoculated into uric acid selective medium for preliminary screening of enzyme-producing strains. The separated single colonies were then inoculated into uric acid selective medium, and streaked repeatedly for multiple times to purify the enzyme-producing strains. The strains are shown in FIG2 .

3) Morphological observation of strains

The colonies on the above plate were selected, made into slides, and Gram staining was performed. The colony morphology was observed under a microscope. The Gram-positive microscopic examination results are shown in Figure 3. The strain was blue-purple under Gram staining, indicating that the strain was Gram-positive bacteria. The colony morphology was uniform, short rod-shaped, and the arrangement was single.

4) Molecular biological identification of strains

The above strains were subjected to 16S rRNA sequencing, and the 16S rRNA sequence of the strain is shown in Seq ID NO: 1. The result of the comparison on NCBI was Bacillus (Bacillaceae), and the measured sequence was uploaded to GenBank with the number: OR294314.

Among them, the 16S rRNA of the strain was amplified using universal primers for bacteria:

Upstream primer 27F: 5-AGAGTTTGATCCTGGCTCAG-3

Downstream primer 1492R: 5-CTACGGCTACCTTGTTACGA-3

The PCR system is shown in Table 1 below.

Table 1 PCR system

The PCR amplification program is shown in Table 2 below.

Table 2 PCR amplification program

The PCR product after the strain purification was taken and sequenced. The measured 16S rRNA sequence was compared with NCBI BLAST, and the highest homology with Bacillus (Bacillaceae gen.sp.) in Genebank was 96.39%. Based on the 16S rRNA gene sequence comparison results, the Neighbor-Joining phylogenetic tree constructed with Oceanobacillus halotolerans strain YIM 98839 as an outer branch was shown in Figure 4, and the strain was preliminarily identified as Bacillus sp. XRK-1.

Example 2

Optimization of fermentation conditions of Bacillus XRK-1

(1) Effect of additional carbon source on the uric acid degradation ability of the strain

On the basis of the uric acid selective medium (plate), an additional carbon source (glucose, sucrose, raffinose, citric acid, oil) with a concentration of 2% was added to detect the effect of adding different additional carbon sources on the uric acid degradation ability of the strain. The detection index is the ratio of the transparent circle size to the colony size.

(2) Effect of additional nitrogen source on the uric acid degradation ability of the strain

On the basis of uric acid selection medium (plate), additional nitrogen sources (peptone, yeast extract, potassium nitrate, ammonium nitrate, ammonium sulfate) with a concentration of 1% were added to detect the effect of adding different additional nitrogen sources on the uric acid degradation ability of the strain. The detection index is the ratio of the transparent circle size to the colony size.

(3) Effect of pH on uric acid degradation ability of strains

On the basis of uric acid selective medium (plate), different pH values (6, 6.5, 7, 7.5, 8) were set to detect the effect of different pH values on the uric acid degradation ability of the strain. The detection index was the ratio of the transparent circle size to the colony size.

Table 3 Effects of different culture factors on the uric acid-lowering ability of Bacillus XRK-1

From the experimental results in Table 3, it can be seen that the top three carbon sources that improve the uric acid degradation ability of the strain are glucose, sucrose and raffinose, the top three nitrogen sources that improve the uric acid degradation ability of the strain are peptone, yeast extract and potassium nitrate, and the top three pH values that improve the uric acid degradation ability of the strain are 6, 7 and 7.5.

(4) Orthogonal experiment to optimize the optimal culture conditions

Based on the results of the single factor experiment, the carbon source, nitrogen source, and pH, which have a greater impact on the cultured strain, were selected for a three-factor three-level orthogonal optimization experiment. The experimental groups were designed according to the factor distribution group shown in Table 4 on the uric acid selection medium (plate), where the concentration of the additional carbon source was 2%, and the concentration of the additional nitrogen source was 1%. The diameter of the transparent circle and the diameter of the colony were measured by the cross method, and the ratio of the diameter of the transparent circle to the diameter of the colony circle was calculated to select the best culture conditions.

Table 4 Orthogonal experimental factors

The experimental results in Table 5 show that Bacillus XRK-1 has the highest efficiency in decomposing uric acid under the conditions of adding sucrose, yeast extract and pH 7, and the ratio of its transparent zone to colony diameter is 6.11. From the range analysis, pH has the greatest impact on the strain, and pH> additional nitrogen source> additional carbon source. Therefore, the fermentation medium of Bacillus XRK-1 was screened as follows: 20g sucrose, 10g yeast extract, 17.1g disodium hydrogen phosphate, 3g potassium dihydrogen phosphate, 0.5g magnesium sulfate, 0.01g anhydrous calcium chloride, 2g uric acid, 1L distilled water, pH 7.0.

Table 5 Experimental results of the effect of fermentation medium composition and pH on uric acid lowering ability

(5) Growth curve of XRK-1 under optimal culture conditions.

From the above experimental results, it can be seen that XRK-1 has the highest efficiency in decomposing uric acid in a uric acid selection medium (liquid) with 2% sucrose, 1% yeast extract, and pH 7.0. The fermentation medium is configured with 20g sucrose, 10g yeast extract, 17.1g disodium hydrogen phosphate, 3g potassium dihydrogen phosphate, 0.5g magnesium sulfate, 0.01g anhydrous calcium chloride, 2g uric acid, 1L distilled water, and pH 7.0. Then, Bacillus XRK-1 is inoculated according to 5% of the culture medium, and then placed in a constant temperature shaking incubator (37°C, 180r/min) for shaking culture for 24h. The fermentation liquid is taken and centrifuged every 1h, and then the absorbance is measured at 600nm with a wind photometer. The content of Bacillus XRK-1 is calculated according to OD _600. The results are shown in Figure 5. As shown in Figure 5, the strain Bacillus XRK-1 grows rapidly in the early stage, and the growth gradually slows down after 15h. The content of Bacillus XRK-1 reaches the highest after 24h of fermentation.

(6) The urate oxidase activity of Bacillus subtilis XRK-1 produced in the uric acid selective medium and the fermentation medium was detected using an ELISA instrument.

A single colony was inoculated into 100 mL of uric acid selection medium (control group) and fermentation medium (optimized group) at an inoculum size of 2%, and the cells were placed in a constant temperature shaking incubator (37°C, 180 r/min) for shaking culture for 36 h. 1.0 mL of culture medium was taken respectively, and the supernatant was transferred into a new EP tube (5500×g, 10 min, 4°C) after centrifugation. 900 μL PBS was added to the bacterial precipitate, and the cells were ultrasonically broken on ice. The supernatant was taken after centrifugation for later use.

Uric acid standard solutions with concentrations of 0.1, 0.2, 0.3, 0.4, and 0.5 mmol were prepared, and the absorbance at 300 nm was measured to prepare a UA standard curve, as shown in FIG6 . Under standard conditions, the amount of sample that consumes 1.0 μmol of uric acid per minute is one enzyme activity unit.

Sample enzyme activity determination: 40 μL of the supernatant of the strain culture broth or the supernatant of the strain disruption broth after fermentation in the uric acid selection medium (control group) and the fermentation medium (optimized group) were taken, and 160 μL of 0.5 mmol uric acid solution prepared with borate buffer (5 mmol HBO, pH 8.5) was added. In a standard 96-well plate, 37°C, 300 nm (AU300), aerobic for 60 min, the reduction of uric acid was monitored, and the uric acid concentration was determined by OD ₃₀₀ absorbance readings according to Figure 6.

Referring to Figure 7, the enzyme activity produced by Bacillus XRK-1 cultured in the uric acid selective medium (control group) was 0.047U/ml; the urate oxidase activity produced by the strain of Bacillus XRK-1 cultured in the fermentation medium optimized by the inventors (optimized group) was 0.103U/ml. Therefore, the optimized fermentation medium can significantly improve the enzyme activity of urate oxidase produced by Bacillus XRK-1.

In summary, the Bacillus XRK-1 of the present invention has the ability to produce high urate oxidase, thereby efficiently degrading urine. The microbial preparation prepared by fermentation of Bacillus XRK-1 can be used to lower uric acid, and the application of Bacillus XRK-1 in the preparation of uric acid-lowering drugs has great potential in the preparation of drugs for alleviating hyperuricemia, preventing and treating gout, anti-inflammation, improving intestinal flora and other diseases.

Example 3

A microbial preparation is produced by fermentation of the uric acid-degrading Bacillus XRK-1 in Example 1.

The microbial preparation of this embodiment is a live bacterial powder of Bacillus XRK-1, which is produced by fermenting Bacillus XRK-1 in the fermentation medium obtained in Example 2. The preparation method thereof comprises the following steps:

S1, inoculating the fermentation strain into the fermentation medium, and fermenting and culturing at 37° C. for 24 hours to obtain a fermentation culture of Bacillus; wherein the fermentation strain is obtained by seed culture of Bacillus XRK-1 strain;

S2, centrifuging the fermented culture of Bacillus to harvest bacterial cells and/or spores of Bacillus;

S3, washing the bacterial cells and/or spores of Bacillus obtained in S2 with physiological saline to obtain pure bacterial cells and/or spores of Bacillus, and then freeze-drying them to obtain freeze-dried powder, which is live bacterial powder of Bacillus XRK-1.

Based on the fact that the live bacterial powder of Bacillus XRK-1 of this example has the ability to degrade uric acid in vitro, the applicant also proposed the use of the microbial preparation of this example in the preparation of uric acid-lowering drugs.

Example 4

A microbial preparation is produced by fermentation of the uric acid-degrading Bacillus XRK-1 in Example 1.

The microbial preparation of this embodiment is a Bacillus XRK-1 postbiotic, which is produced by fermenting Bacillus XRK-1 in the fermentation medium obtained in Example 2. The preparation method thereof comprises the following steps:

S1, inoculating the fermentation strain into the fermentation medium, and fermenting and culturing at 37° C. for 24 hours to obtain a fermentation culture of Bacillus; wherein the fermentation strain is obtained by seed culture of Bacillus XRK-1 strain;

S2. The fermentation culture of Bacillus XRK-1 is subjected to cell lysis, high temperature inactivation (121° C., 30 min), and concentration to obtain postbiotics containing Bacillus cells and their metabolites.

Based on the fact that the Bacillus XRK-1 bacteria of this example have the ability to degrade uric acid in vitro, the applicant also proposed the use of the microbial preparation of this example in the preparation of uric acid-lowering drugs.

Example 5

A microbial preparation is produced by fermentation of the uric acid-degrading Bacillus XRK-1 in Example 1.

The microbial preparation of this embodiment is a composition of live bacterial powder of Bacillus XRK-1 and metabolites. The microbial preparation is produced by fermenting Bacillus XRK-1 in the fermentation medium obtained in Example 2. The preparation method thereof comprises the following steps:

S1, inoculating the fermentation strain into the fermentation medium, and fermenting and culturing at 37° C. for 24 hours to obtain a fermentation culture of Bacillus; wherein the fermentation strain is obtained by seed culture of Bacillus XRK-1 strain;

S2, centrifuging the fermented culture of Bacillus to obtain bacterial cells and/or spores of Bacillus;

S3, centrifuging the fermentation culture of Bacillus in step S2 to obtain a supernatant, inactivating it at high temperature (121° C., 30 min), centrifuging it, and concentrating it to obtain metabolites;

S4. The bacterial cells/spores of Bacillus obtained in S2 and the metabolites obtained in S3 are mixed and freeze-dried to obtain a lyophilized powder, which is the microbial preparation of the present application.

Based on the fact that the Bacillus XRK-1 bacteria of this example have the ability to degrade uric acid in vitro, the applicant also proposed the use of the microbial preparation of this example in the preparation of uric acid-lowering drugs.

The present invention discloses a microbial preparation prepared by fermentation of bacillus capable of degrading uric acid. It may also be a composition obtained by mixing live bacterial powder of Bacillus XRK-1 and postbiotics at a weight ratio of 2:1, or a composition obtained by mixing Bacillus XRK-1 spores and metabolites at a weight ratio of 3:1. The composition of the microbial preparation can adjust the ratio of the individual components according to the application. The changes of the above technical features can be understood and implemented by those skilled in the art through text descriptions, so no further drawings are provided for illustration.

Claims (10)

1. A Bacillus that can degrade uric acid, characterized in that the Bacillus is Bacillus XRK-1 (Bacillus sp. XRK-1), the deposit number is: CCTCC M 20232477, the deposit date is: December 6, 2023, and the deposit unit is: China Center for Type Culture Collection. 2. The uric acid-degrading Bacillus according to claim 1, characterized in that the Bacillus is isolated from a sunflower disk, and the 16S rRNA sequence of the Bacillus XRK-1 is shown in Seq ID NO: 1. 3. The uric acid-degrading Bacillus according to claim 1 or 2, characterized in that the Bacillus has the ability to produce urate oxidase to degrade uric acid and can efficiently degrade uric acid in vitro. 4. The uric acid-degrading Bacillus according to claim 3, characterized in that the urate oxidase activity produced by the Bacillus XRK-1 after fermentation for 36 hours is as high as 0.103 U/ml. 5. A microbial preparation, characterized in that it is produced by fermentation of the uric acid-degrading Bacillus according to any one of claims 1 to 4. 6. The microbial preparation according to claim 5, characterized in that the microbial preparation comprises one or more of live Bacillus XRK-1 bacteria, spores, inactivated Bacillus XRK-1 bacteria, metabolites and postbiotics thereof. 7. A method for preparing a microbial preparation, characterized in that the method for preparing the microbial preparation comprises the following steps: S1. Inoculating the fermentation strain into a fermentation medium for fermentation culture to obtain a fermentation culture of Bacillus; wherein the fermentation strain is obtained by seed culture of Bacillus XRK-1 strain; S2. Centrifugation is performed on the fermentation culture of Bacillus to harvest bacterial cells and/or spores of Bacillus. 8. The method for preparing a microbial preparation according to claim 7, characterized in that S2 further comprises washing the bacterial cells and/or spores of Bacillus with physiological saline to obtain pure bacterial cells and/or spores of Bacillus. 9. The method for preparing a microbial preparation according to claim 7, characterized in that the method for preparing a microbial preparation further comprises the following steps: S3, the supernatant of the fermentation culture of Bacillus after centrifugation is inactivated at high temperature (121°C, 30 min), centrifuged and concentrated to obtain metabolites; S4, subjecting the fermentation culture of Bacillus to cell lysis, high temperature inactivation (121° C., 30 min), and concentration to obtain postbiotics containing Bacillus cells and their metabolites; S5. Freeze-dried powder obtained by freeze-drying one or more of the bacterial cells, spores, metabolites and postbiotics of Bacillus. 10. The method for preparing a microbial preparation according to claim 7, characterized in that, in S1, the fermentation culture temperature is 30-45°C, and the fermentation medium is composed of the following raw materials: 20 g sucrose, 10 g yeast extract, 17.1 g/L disodium hydrogen phosphate, 3 g/L potassium dihydrogen phosphate, 0.5 g/L magnesium sulfate, 0.01 g/L anhydrous calcium chloride, 2 g uric acid, distilled water, pH 7.0, and high pressure sterilization at 121°C for 25 min.