Leuconostoc mesenteroides subsp. mesenteroides and application thereof

Abstract

This application provides a strain of *Leuconostoc mesenteroides* subsp. *ménica* with uric acid-lowering effects and its applications, belonging to the field of microbial technology. Specifically, this strain is *Leuconostoc mesenteroides* subsp. *ménica* (… Leuconostoc mesenteroides subsp. mesenteroides SCFF808 was deposited on March 17, 2026, at the China General Microbiological Culture Collection Center (CGMCC), with accession number CGMCC No. 37947. Experiments have shown that the strain provided in this application exhibits significant abilities to degrade purine nucleosides, inhibit XOD enzymes, and degrade uric acid both in vitro and in vivo, demonstrating promising application prospects in the prevention and treatment of hyperuricemia.

Description

Technical Field

[0001] This invention belongs to the field of microbial technology, and in particular relates to a strain of Leuconostoc mesenteroides SCFF808 and its application in the preparation of a highly efficient uric acid-lowering bacterial agent. Background Technology

[0002] Hyperuricemia is a metabolic disease caused by purine metabolism disorders, characterized by abnormally elevated serum uric acid levels. Currently, clinical treatment for hyperuricemia mainly relies on drug intervention, including allopurinol and febuxostat to inhibit uric acid synthesis, benzbromarone and probenecid to promote uric acid excretion, and pegologase to promote uric acid breakdown. However, these chemical drugs generally have significant adverse reactions and poor patient compliance. Therefore, developing safe, efficient, and sustainable uric acid-lowering replacement strategies has important clinical value and social significance.

[0003] With the deepening of research on gut microbiota, some probiotic strains with uric acid-lowering activity have been discovered, such as patents CN110684685A, CN110184209A, and CN116218746A. However, the efficacy levels and target points of strains provided by existing technologies vary significantly. Furthermore, most strains only possess a single purine metabolism pathway and fail to simultaneously achieve the dual mechanism of "reducing substrate absorption" and "inhibiting uric acid synthesis." At the same time, the correlation between in vitro activity and in vivo efficacy is insufficiently validated. Therefore, screening for superior strains with efficient purine nucleoside degradation, XOD inhibition, and direct uric acid clearance capabilities is of significant technical value for developing novel uric acid-lowering probiotic preparations.

[0004] Qinghai dairy milk, a traditional fermented food, is made from yak milk unique to the Qinghai-Tibet Plateau through natural fermentation. The finished product is rich in active lactic acid bacteria, high-quality protein, and functional nutrients, and is traditionally recognized for its health benefits, such as aiding digestion and regulating the intestinal microecology. However, the screening and identification of core functional strains in Qinghai dairy milk and the systematic evaluation of its specific effects remain incomplete.

[0005] Leuconostoc mesenteroides ( Leuconostoc mesenteroides Leuconostoc mesenteroides is an important species of lactic acid bacteria in the genus Leuconostoc. It has a long history of safe consumption and is widely found on the surface of plants and in traditional fermented foods. It is often used in the production of fermented dairy products, silage, pickles and fruit wines. However, there are no reports on the ability of Leuconostoc mesenteroides to lower uric acid. Summary of the Invention

[0006] To address the aforementioned issues, this application provides a novel strain isolated from traditional dairy milk in Qinghai Province—*Leuconostoc mesenteroides* subsp. *mesenteroides*. Leuconostoc mesenteroides subsp. mesenteroidesThe study identified SCFF808 and elucidated its purine metabolism characteristics and uric acid-lowering mechanism, establishing a complete evaluation system from in vitro to in vivo and from mechanism to efficacy, providing a new technical path for the functional development and high-value utilization of traditional fermented foods.

[0007] On the one hand, this application provides a strain of Leuconostoc mesenteroides subsp. mesenteroides ( Leuconostoc mesenteroide s subsp. mesenteroides Leuconostoc mesenteroides SCFF808 was deposited on March 17, 2026, 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. 37947.

[0008] In one embodiment, the Leuconostoc mesenteroides subsp. SCFF808 is obtained by isolating it from casein.

[0009] In one embodiment, the single colony morphology of *Leuconostoc mesenteroides* subsp. *enteroides* SCFF808 on MRS agar medium is milky white, round, with a raised center and neat edges. It is Gram-positive, and the bacteria are arranged in spherical, multi-layered chains of varying lengths.

[0010] On the other hand, this application also provides the application of the aforementioned Leuconostoc mesenteroides subsp. SCFF808 in the preparation of microbial agents with uric acid-lowering effects.

[0011] Optionally, the Leuconostoc mesenteroides subsp. SCFF808 is used as the sole active ingredient in the microbial agent.

[0012] On the other hand, this application also provides a microbial agent whose active ingredients include live bacteria, inactivated bacteria, cell-free supernatant and / or cell-free extract of Leuconostoc mesenteroides SCFF808.

[0013] In one embodiment, the inactivated bacterial cells of the strain can be prepared using chemical or physical methods known in the art, such as heating, ultrasound, irradiation, treatment with chemical reagents such as formaldehyde, etc.

[0014] In one embodiment, the cell-free supernatant of the strain can be obtained by the following method: After culturing strain SCFF808 for a period of time, centrifuge and filter the supernatant through a 0.22 μm filter membrane to obtain cell-free supernatant.

[0015] In one embodiment, the cell-free extract of the strain can be obtained by the following method: After culturing strain SCFF808 for a period of time, centrifuge and separate the supernatant to obtain the bacterial cell precipitate; sonicate the bacterial cell precipitate to disrupt the bacterial cells, centrifuge, and obtain the supernatant to obtain the cell-free extract.

[0016] In one embodiment, the microbial agent further includes a carrier for loading the active component. The carrier can be a commonly known carrier in the art, such as a solid carrier, a semi-solid carrier, or a liquid carrier.

[0017] In one embodiment, the microbial agent comprises a suspension and / or lyophilized powder of the active ingredient.

[0018] Preferably, the microbial agent is a lyophilized powder of strain SCFF808, which can be prepared using methods known in the art. For example, after culturing strain SCFF808 for a period of time, the bacterial cells are centrifuged, washed, and a lyophilization protectant is added. The cells are then freeze-dried under vacuum to obtain the lyophilized powder, which is stored at -20°C. Optionally, the concentration of the lyophilized powder of strain SCFF808 obtained by this method is (1~2)×10⁻⁶. 11 CFU / g.

[0019] On the other hand, this application also provides the use of the aforementioned Leuconostoc mesenteroides subsp. SCFF808 and / or the aforementioned microbial agent in the preparation of products with uric acid degradation effects or for the prevention and treatment of hyperuricemia.

[0020] In one embodiment, the product is used to degrade purine nucleosides, inhibit xanthine oxidase, and / or directly degrade uric acid.

[0021] In one embodiment, the purines include guanine and hypoxanthine, and the nucleosides include inosine and guanosine.

[0022] In one embodiment, the product includes pharmaceuticals and / or functional foods.

[0023] In one embodiment, the content of Leuconostoc mesenteroides subsp. enterica SCFF808 or the microbial agent in the product is 0.01% to 99.99%, for example, 0.01% to 50%, 0.01% to 40%, 0.01% to 30%, 0.01% to 20%, 0.01% to 10%, etc., where % is a mass percentage (w / w), a volume percentage (v / v), a mass-to-volume ratio (w / v), or a volume-to-mass ratio (v / w).

[0024] On the other hand, this application also provides a probiotic product with uric acid-lowering effects, wherein the active ingredients of the product include the Leuconostoc mesenteroides subsp. enterica SCFF808 and / or the microbial agent.

[0025] In one embodiment, the product includes pharmaceuticals and / or functional foods.

[0026] On the other hand, this application also provides a drug for the prevention and treatment of hyperuricemia, wherein the active ingredients of the product include the Leuconostoc mesenteroides subsp. enterica SCFF808 and / or the microbial agent.

[0027] On the other hand, this application also provides a health food product with uric acid-lowering effects, wherein the active ingredients of the product include the Leuconostoc mesenteroides subsp. enterica SCFF808 and / or the microbial agent.

[0028] Optionally, the product, drug, or health food may also include at least one pharmaceutically acceptable excipient or carrier, such as water.

[0029] Optionally, the dosage form of the product, drug, or health food can be a commonly used oral dosage form in pharmaceuticals, such as tablets, granules, oral liquids, capsules, etc.

[0030] Optionally, the product, drug, or health food may also include components that help lower uric acid, such as flavonoids that reduce uric acid synthesis or dietary fiber that promotes uric acid excretion; or it may include components with other biological activities, such as components with antioxidant or anti-inflammatory activities.

[0031] This application has at least the following beneficial effects: This application identified a strain of *Leuconostoc mesenteroides* subsp. SCFF808 with highly efficient purine degradation capabilities from Qinghai dairy product using a combination of directional screening on uric acid medium and HPLC system. The strain has the accession number CGMCC No. 37947. Experiments revealed the following advantages of this strain: (1) It can simultaneously and efficiently degrade purines and nucleosides, with a degradation rate of approximately 78% for guanine, approximately 77% for hypoxanthine, approximately 85% for inosine, and approximately 83% for guanosine; (2) It has a certain ability to inhibit xanthine oxidase, and the xanthine oxidase inhibition capacity of its cell-free supernatant and cell-free extract is 63% and 57%, respectively; (3) It has the ability to directly degrade uric acid in vitro, and can degrade 25 mg / L of uric acid 100% in vitro in 16 h; (4) In the zebrafish model experiment with high uric acid, the uric acid fluorescence value of zebrafish treated with different doses of this bacterial agent was significantly lower than that of the model control group. p <0.001).

[0032] Therefore, the *Leuconostoc mesenteroides* subsp. *enteroides* SCFF808 strain provided in this application can simultaneously achieve a dual mechanism of "reducing substrate absorption" and "inhibiting uric acid synthesis," thereby lowering uric acid levels, and has demonstrated a significant ability to degrade uric acid both in vivo and in vitro. Furthermore, *Leuconostoc mesenteroides* is also included in the "List of Microbial Strains that Can Be Used in Food," has a long history of safe consumption, high safety, and great application potential. Attached Figure Description

[0033] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 The standard curves for guanine and hypoxanthine in Example 1; Figure 2 The graph shows the degradation rates of guanine and hypoxanthine by the eight strains in Example 1. Figure 3 The colony morphology identification results of strain SCFF808 in Example 1 are shown in Figure a, where a is a colony morphology diagram and b is a Gram staining result diagram. Figure 4 The growth curve of strain SCFF808 in Example 1; Figure 5 This is a graph showing the nucleoside degradation rate of strain SCFF808 in Example 2; Figure 6 This is a graph showing the in vitro xanthine oxidase inhibition rate of strain SCFF808 in Example 3; Figure 7 This is a graph showing the in vitro uric acid-lowering ability of strain SCFF808 in Example 4; Figure 8 The image shows the results of the uric acid-lowering effect of strain SCFF808 in zebrafish in Example 5. Detailed Implementation

[0034] To more clearly illustrate the overall concept of this application, a detailed description is provided below with reference to the accompanying drawings. The following embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the invention. Any modifications, equivalent substitutions, or improvements made by those skilled in the art without departing from the principles of the present invention should be included within the scope of protection of the present invention.

[0035] Unless otherwise specified, all materials, reagents, and equipment used in the following examples are commercially available products. Some reagents or instruments and their sources are shown in Table 1: Table 1

[0036] Example 1: Isolation and Screening of Strains The specific experimental procedure is as follows: 1. Isolation of strains Aseptically collected casein samples from three herding families in Henan Mongolian Autonomous County, Huangnan Tibetan Autonomous Prefecture, Qinghai Province, were stored at low temperature and sent to the laboratory. One mL of each sample was added to 97 mL of sterile physiological saline, vortexed, and serially diluted. The samples were then spread onto glucose-free MRS aerobic and anaerobic agar plates containing 10 mM uric acid and incubated at 37°C for 7 days. Twenty distinctly morphologically different single colonies were picked and inoculated into 5 mL of glucose-free MRS aerobic or anaerobic broth containing 5 mM uric acid. The cultures were incubated at 37°C for 72 h, yielding eight pure cultures, named SCFF805, SCFF807, SCFF808, SCFF809, SCFF810, SCFF813, SCFF814, and SCFF815, for screening uric acid-lowering strains.

[0037] 2. Initial screening of strains with highly efficient purine degradation capabilities in vitro Guanine and hypoxanthine are located at key upstream and midstream nodes in purine metabolism, respectively. The ability of a strain to degrade guanine reflects its guanine deaminase activity and its potential to block uric acid formation from the upstream pathway. Hypoxanthine, derived from both adenine and guanine, is a direct substrate of xanthine oxidase and a crucial precursor in the final stage of uric acid formation. The ability of a strain to degrade hypoxanthine directly determines its effectiveness in inhibiting the final formation of uric acid. Therefore, this invention selects guanine and hypoxanthine as core indicators for HPLC initial screening to detect the purine degradation ability of the selected strains.

[0038] (1) Construction of the purine standard curve Preparation of a mixed standard working solution of guanine and hypoxanthine: Weigh out 5 mg each of guanine and hypoxanthine standards, dissolve them in 1 mol / L NaOH solution, and then dilute to volume with 0.1 mol / L K3PO4 solution to prepare 1.0 mg / mL single-item standard stock solutions. Store at 4℃ protected from light. Take appropriate amounts of the above two purine single-item standard stock solutions and dilute to volume with 0.1 mol / L K3PO4 solution to prepare guanine-hypoxanthine mixed standard working solutions of 5, 10, 20, 30, 40, and 50 mg / L.

[0039] Chromatographic conditions: 254 nm; flow rate: 1.0 mL / min; injection volume: 10 μL; column temperature: 25℃; mobile phase A: acetonitrile, mobile phase B: water, mobile phase C: methanol, mobile phase D: potassium dihydrogen phosphate.

[0040] Standard curve construction: A series of mixed standard working solutions of varying concentrations were injected and analyzed under the chromatographic conditions described above. Linear regression analysis was performed on the peak areas of guanine and hypoxanthine standards against their respective mass concentrations to construct standard curves. The results are as follows: Figure 1 As shown.

[0041] Depend on Figure 1 The results show that guanine and hypoxanthine exhibit good linearity within their respective concentration ranges, with a correlation coefficient R0. 2 All are 0.999.

[0042] (2) Initial screening of purine-degrading strains Pretreatment methods for screening strains: Eight bacterial strains obtained through directional screening on uric acid-selective medium—SCFF805, SCFF807, SCFF808, SCFF809, SCFF810, SCFF813, SCFF814, and SCFF815—were selected as initial screening targets. They were inoculated at a ratio of 3% into MRS anaerobic medium and incubated statically at 37°C for 24 h. The bacterial pellet was collected by centrifugation at 5000 g for 10 min at 4°C. The bacterial cells were washed three times with sterile PBS and resuspended in PBS for later use. OD was adjusted. 600 The value was 1.0. One mL of bacterial suspension was centrifuged at 5000 g for 10 min, then 750 μL of hypoxanthine-guanine-neutral potassium phosphate buffer (25 mg / L) was added. The mixture was incubated at 37℃ for 1 h, and after centrifugation, 720 μL of the supernatant was collected. The reaction was terminated by adding 80 μL of 0.1 mol / L HClO4. The sample was filtered through a 0.22 μm microporous membrane, and 10 μL was used for HPLC analysis.

[0043] HPLC determination and degradation rate calculation: Injection and determination were performed according to the chromatographic conditions of the standards, and the residual concentration of each purine in the sample was calculated based on the standard curve. The purine degradation rate of the strains was calculated using the following formula: Degradation rate = (C1 - C2) / C1 × 100%. Where C1 is the initial concentration of the purine standard (mg / L); C2 is the concentration of the remaining purine standard (mg / L). The degradation rates of guanine and hypoxanthine calculated for the above 8 strains are as follows: Figure 2 As shown.

[0044] Depend on Figure 2 The results showed that strain SCFF808 had the highest purine degradation efficiency, with guanine residue of 5.40 mg / L after incubation, a degradation rate of approximately 78%, and hypoxanthine residue of 5.73 mg / L, a degradation rate of approximately 77%.

[0045] 3. Strain identification (1) Molecular biological identification The SCFF808 strain obtained from the initial screening was used to extract the genome using a bacterial genomic DNA extraction kit. 16S rRNA was routinely amplified using primers 27F (5'-AGAGTTTGATCCTGGCTCAG-3') and 1492R (5'-TACGGCTACCTTGTTACGACTT-3'). The amplified products were sent to Beijing Qingke Biotechnology Co., Ltd. for sequencing. The sequencing results were analyzed using a BLAST tool (http: / / www.ncbi.nlm.nih.gov / blast) to compare the isolated 16S rDNA sequence with the NCBI database. The results showed that it was similar to *Leuconostoc mesenteroides* subsp. *enteroides* ATCCC8293 (…). Leuconostoc mesenteroides subsp. mesenteroides The nucleic acid sequence similarity of ATCC8293 was as high as 100%, and it was named Leuconostoc mesenteroides subsp. mesenteroides (ATCC8293). Leuconostoc mesenteroides subsp. mesenteroides )SCFF808.

[0046] This is the enteromembranous subsp. *Leuconostoc mesenteroides* ( Leuconostoc mesenteroides subsp. mesenteroides SCFF808 was deposited on March 17, 2026, at the China General Microbiological Culture Collection Center (CGMCC), with accession number CGMCC No. 37947, located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing.

[0047] (2) Identification of colony morphology Single colonies of the selected strains were inoculated into MRS broth medium and cultured at 37°C until the logarithmic development phase. The colonies were then streaked onto MRS plates and incubated at 37°C for 2–3 days. Single colony morphology was observed. Gram staining experiment: Fresh plate colonies were smeared and fixed. Crystal violet staining solution was added, and the smear was washed with water after 1 min. Iodine solution was added, covering the smear for 1 min. The smear was destained with 95% alcohol, washed with water, and counterstained with safranin solution for 1 min. After washing with water, cell morphology was observed under a 100× oil immersion microscope and photographed. The results are as follows: Figure 3 As shown.

[0048] Depend on Figure 3 As can be seen, on MRS agar medium, colonies are milky white, round, with a raised center, neat edges, and a size of 1-2 mm. Figure 3 The Gram staining results in b show that the bacteria are Gram-positive and the cells are arranged in spherical, multi-layered chains of varying lengths.

[0049] 4. Growth curve of Leuconostoc mesenteroides subsp. enterica SCFF808 After overnight culture, SCFF808 strain was inoculated into MRS anaerobic medium and cultured at 37°C. OD was measured every 2 hours using a cell density meter.600 The culture medium without inoculation of the strain was used as a blank control. Each group was divided into three replicates, and the assay was performed for a total of 24 hours. The results are as follows: Figure 4 As shown.

[0050] Depend on Figure 4 The results show that SCFF808 grows well in MRS medium, with a short lag phase, entering the logarithmic growth phase after 4 hours and reaching the stationary phase after 18 hours.

[0051] 5. Preparation of Leuconostoc mesenteroides subsp. enterica SCFF808 bacterial agent Strain SCFF808 was inoculated at a rate of 3% into 100 mL of anaerobic MRS broth and cultured overnight at 37°C. Then, it was inoculated at a rate of 3% into 3 L of anaerobic MRS broth and cultured at 37°C for 24 h. After centrifugation at 6000 r / min for 10 min, the bacterial cells were washed twice with sterile physiological saline, and then freeze-dried under vacuum with a lyophilization protectant to obtain bacterial powder. The concentration of the obtained bacterial powder was determined to be 1.42 × 10⁻⁶ using the plate count method. 11 CFU / g, store at -20℃ for later use.

[0052] Example 2: Nucleoside Degradation Capacity Test Nucleosides are important precursors in the purine metabolism pathway, and can be metabolized into corresponding purine bases in organisms. To further explore the broad spectrum of purine metabolism of strain SCFF808 and its application potential in the degradation of nucleosides, this example measured its ability to degrade nucleosides.

[0053] The treatment methods for the strains, chromatographic conditions, preparation methods for inosine and guanosine standards, and the plotting of standard curves all followed the method for determining purine degradation capacity in Example 1. Inosine showed good linearity in the concentration range of 5–50 mg / L. 2 =0.999, the standard curve is Y = 22058X + 29450; guanosine showed good linearity in the concentration range of 5~50 mg / L. 2 =0.999, the standard curve is Y = 27275X + 16471. Substituting the peak areas of inosine and guanosine into the standard curve, the residual nucleoside content was calculated, and the degradation rate was calculated using the formula: Degradation rate = (C1 - C2) / C1 × 100%. Where C1 is the initial concentration of the nucleoside standard solution (mg / L); C2 is the concentration of the remaining nucleoside standard solution (mg / L). The results are as follows... Figure 5 As shown.

[0054] Depend on Figure 5The results showed that after incubation, the inosine content was approximately 3.85 mg / L, with a nucleoside degradation rate of approximately 85%; the guanosine content was 4.24 mg / L, with a nucleoside degradation rate of approximately 83%. These results indicate that strain SCFF808 possesses strong inosine and guanosine degradation capabilities.

[0055] Example 3: In vitro XOD inhibition rate test Excessive uric acid production is one of the main pathogenic mechanisms of hyperuricemia. Xanthine oxidase (XOD) is a key rate-limiting enzyme that catalyzes uric acid synthesis. Inhibiting its activity can effectively block uric acid synthesis and is an important target for uric acid-lowering intervention.

[0056] After verifying the degradation ability of strain SCFF808 on upstream substrates such as purines and nucleosides in Example 2, to further explore its uric acid-lowering mechanism, an in vitro XOD inhibition experiment was first used to evaluate the inhibitory activity of this strain on key enzymes in uric acid synthesis, in order to clarify whether it exerts its effect by inhibiting the uric acid production pathway. The specific steps are as follows: After overnight culture, strain SCFF808 was inoculated into anaerobic MRS medium and cultured at 37°C until OD500. 600 Centrifuge at 8000 rpm for 10 min at 4℃ (1.0) to obtain cell-free supernatant and bacterial pellet. The cell-free supernatant was placed on ice for testing; the bacterial pellet was washed twice with PBS and the bacterial concentration was adjusted to 1×10⁻⁶. 9 Cells / mL. Take 1 mL of the above bacterial culture, sonicate (200W, 40 kHz, 5 s on, 5 s off) for 10 min to disrupt the bacterial cells, then centrifuge at 10000 g for 10 min at 4℃. Collect the supernatant and filter it through a 0.22 μm filter membrane to obtain the cell-free extract. Take 50 μL of the cell-free supernatant and cell-free extract to be tested, respectively, and determine the XOD inhibition rate according to Table 2. Use 1.5 mM allopurinol solution as a positive control and blank MRS medium as a negative control.

[0057] Table 2. Methods for testing xanthine oxidase inhibition rate

[0058] Calculation formula: Inhibition rate = 1 - (A1 - A2) / (A3 - A4). Where: A1 represents the absorbance of the test tube; A2 represents the absorbance of the control tube; A3 represents the absorbance of the negative control tube; A4 represents the absorbance of the negative control tube. The xanthine oxidase concentration is 0.04 U / mL; the xanthine solution concentration is 0.4 mM. The calculation results are as follows: Figure 6 As shown.

[0059] Depend on Figure 6The results showed that the inhibition rate of allopurinol in the positive control group against XOD was about 94%, while the inhibition rates of cell-free supernatant and cell-free extract of strain SCFF808 against XOD were about 63% and 57%, respectively, which were much higher than the 5% of the blank MRS, indicating that strain SCFF808 has a significant inhibitory effect on XOD activity.

[0060] Example 4: In vitro uric acid-lowering capacity test Uric acid is the end product of purine metabolism, and its accumulation is a direct cause of hyperuricemia. After verifying the upstream degradation ability of strain SCFF808 of purines and nucleosides and its XOD inhibition effect in Examples 2 and 3, this example further measures the bacterium's ability to directly degrade uric acid in vitro, aiming to comprehensively evaluate its application potential in alleviating hyperuricemia.

[0061] The treatment method for strain SCFF808, the preparation of uric acid standards, and the steps for plotting the standard curve were all consistent with the purine determination method in Example 1. The chromatographic conditions were identical to those for purine determination, except that the detection wavelength was adjusted to 290 nm based on the characteristic maximum absorption wavelength of uric acid. Uric acid showed good linearity in the concentration range of 5–50 mg / L. 2 =0.999, the standard curve is Y=40649X + 13916. Substitute the peak area of ​​uric acid into the standard curve to calculate the residual amount, and calculate the degradation rate using the formula: Degradation rate = (C1-C2) / C1×100%. Where C1 is the initial concentration of the uric acid standard solution, mg / L; C2 is the concentration of the remaining uric acid standard solution, mg / L. The results are as follows... Figure 7 As shown.

[0062] Depend on Figure 7 The results showed that uric acid degradation by strain SCFF808 began after 4 hours of incubation, the degradation rate increased rapidly after 8 hours, reached 60% after 12 hours, and reached 100% after 16 hours, meaning that uric acid was completely degraded. This indicates that strain SCFF808 has a strong in vitro uric acid degradation capacity.

[0063] Example 5: Effect of improving uric acid metabolism in zebrafish with high uric acid levels Zebrafish have a short embryonic development cycle, high reproductive capacity, small rearing space requirements, and low cost; they also respond stably to modeling drugs, allowing for the rapid acquisition of a large number of genetically consistent replicates. This embodiment uses zebrafish as a hyperuricemia model to evaluate the in vivo uric acid-lowering efficacy of strain SCFF808.

[0064] Zebrafish, 5 days post-fertilization, were randomly selected and placed in 6-well plates with 3 mL of culture medium per well and 30 fish per well. They were divided into a normal control group, a model control group, a positive control group (benzbromarone), and a sample group. The sample group included three concentration gradients: low, medium, and high, with concentrations of 1.42 × 10⁻⁶. 6 1.42×10 7 1.42×10 8 CFU / mL. The normal control group was cultured under standard conditions. The model control group, positive drug group, and sample group were first induced with a combination of potassium oxonate (10 mM) and xanthine sodium (500 μM) to create a zebrafish hyperuricemia model. Simultaneously, the positive drug group received benzbromarone intervention, and the sample groups received the corresponding concentrations of the test sample. Each group was exposed for 18 h. After exposure, samples were collected from each group, and the uric acid fluorescence value in zebrafish was measured according to the Amplex Red uric acid and uricase assay kit instructions to evaluate the uric acid-lowering efficacy of the samples. The results are as follows: Figure 8 As shown.

[0065] Depend on Figure 8 The results showed that the uric acid fluorescence values ​​of zebrafish treated with different doses of strain SCFF808 were significantly lower than those of the model control group. p The value <0.001 indicates that strain SCFF808 has an auxiliary effect in lowering uric acid.

[0066] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. Leuconostoc mesenteroides subsp. cremosus (Lm) SCFF808, characterized in that, Leuconostoc mesenteroides subsp. mesenteroides ) SCFF808, characterized in that, Lactobacillus intestinalis (Lactobacillus intestinalis Leuconostoc mesenteroides subsp. m esenteroides ) SCFF808 was deposited with China General Microbiological Culture Collection Center (CGMCC) on March 17, 2026, and the deposit number is CGMCC No. 37947.

2. Leuconostoc mesenteroides subsp. mesenteroides (Lm) SCFF808 according to claim 1, characterized in that, Leuconostoc mesenteroides subsp. mesenteroides ) SCFF808, characterized in that, Leuconostoc mesenteroides subsp. Leuconostoc mesenteroides esenteroides subsp. mesenteroides ) SCFF808 was isolated from a cheese serum.

3. The Lactobacillus intestinalis subsp. (Lactobacillus intestinalis subsp. Leuconostoc mesenteroides intestinalis) SCF F808 for use according to claim 1 or 2. mesenteroides ) use of the Lactobacillus intestinalis subsp. (Lactobacillus intestinalis subsp. mesenteroides intestinalis) SCF F808 in the preparation of a microbial inoculant having uric acid-lowering efficacy.

4. A microbial inoculant, characterized in that, The active ingredients include viable cells of Leuconostoc mesenteroides subsp. Leuconostoc mesenteroides mesenteroides (Lm) SCF 808, inactivated cells, cell-free supernatant and / or cell-free extract. mesenteroides ) SCF 808, inactivated cells, cell-free supernatant and / or cell-free extract.

5. The microbial inoculant of claim 4, wherein, The microbial agent comprises a suspension and / or a lyophilized powder of the active ingredient.

6. The Lactobacillus intestinalis (Lactobacillus intestinalis subsp. Leuconostoc mesenteroides subsp. mesenteroides ) SCFF808 of claim 1 or 2, and / or the use of the microbial inoculant of claim 4 or 5 in the preparation of a product having the efficacy of degrading uric acid or for preventing and treating hyperuricemia.

7. Use according to claim 6, characterized in that, The product is used for degrading purine nucleosides, inhibiting xanthine oxidase and / or directly degrading uric acid.

8. Use according to claim 6, characterized in that, The product comprises a pharmaceutical and / or a functional food.

9. Use according to claim 6, characterized in that, said Leuconostoc mesenteroides subsp. Leuconostoc mesenteroides subsp. mesenteroides ) SCFF808 or microbial inoculant in the product is 0.01%~99.99%, the % is mass percentage (w / w), volume percentage (v / v), mass-volume ratio (w / v) or volume-mass ratio (v / w).

10. A probiotic product having a uric acid-lowering effect, characterized in that the active ingredient of the product comprises Leuconostoc mesenteroides subsp. cremosum (Lm) SCFF808 of claim 1 or 2, and / or the microbial inoculum of claim 4 or 5. Leuconostoc mesenteroides subsp. mesent eroides ) SCFF808, and / or the microbial inoculum of claim 4 or 5.

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