Lactobacillus plantarum capable of producing exopolysaccharides and application of lactobacillus plantarum

Abstract

The invention discloses lactobacillus plantarum JS211 capable of producing exopolysaccharides and application of the lactobacillus plantarum JS211, and belongs to the technical field of microorganisms. The invention provides a strain of Lactobacillus plantarum JS211 capable of producing exopolysaccharides, which is preserved in the Guangdong Microbial Culture Collection Center on August 30, 2024, and the preservation number is GDMCC No: 65078. The invention also provides a method for preparing the Lactobacillus plantarum JS211 capable of producing exopolysaccharides, and the Lactobacillus plantarum JS211 capable of producing exopolysaccharides has been preserved in the Guangdong Microbial Culture Collection Center on August 30, 2024. The extracellular polysaccharide is extracted from lactobacillus plantarum JS211 fermentation liquor by utilizing a water extraction and alcohol precipitation method, the scavenging capacity of the extracellular polysaccharide on DPPH and ABTS free radicals is further verified, and the anti-inflammatory capacity of the extracellular polysaccharide is researched by intragastric administration on mice with DSS induced colitis. Results show that the exopolysaccharide prepared from the lactobacillus plantarum JS211 fermentation liquor has antioxidant and / or anti-inflammatory protection capability.

Description

Technical Field

[0001] The invention relates to the field of microorganisms, in particular to a strain of plant lactobacillus producing extracellular polysaccharide and application thereof. Background Art

[0002] Lactobacillus plantarum is a recognized probiotic with an optimal growth temperature of 30-37°C and an optimal pH of about 6.5. It is widely distributed in nature. Lactobacillus plantarum can effectively tolerate the human digestive system, regulate the balance of intestinal flora, and promote human digestion and absorption. Studies have shown that Lactobacillus plantarum has a variety of biological activities, such as lowering cholesterol, regulating intestinal flora, lowering blood sugar, enhancing immunity, and anti-tumor.

[0003] Exopolysaccharide (EPS) refers to the general term for mucus polysaccharides or capsule polysaccharides secreted outside the cell wall by lactic acid bacteria during growth and metabolism. It has rich physical and biological activities, such as protecting bacteria, promoting bacterial adhesion, lowering blood pressure, lowering cholesterol, anti-oxidation, anti-tumor, improving intestinal microecological environment and enhancing human immunity, etc., and is widely used in food, pharmaceutical and cosmetic industries. Exopolysaccharides currently have problems such as unclear functions, complex extraction processes and high production costs. Therefore, it is of great significance to provide a plant lactobacillus that can produce exopolysaccharides and an extraction method that improves the separation purity of such exopolysaccharides. Summary of the invention

[0004] The purpose of the present invention is to provide a plant lactobacillus strain producing extracellular polysaccharide and its application, so as to solve the problems existing in the above-mentioned prior art. The extracellular polysaccharide extracted by the method of the present invention is a fibrous white loose solid substance with a yield of 302 mg / L and a sugar content of 91.2%. The extracellular polysaccharide prepared by the plant lactobacillus strain JS211 of the present invention has antioxidant and / or anti-inflammatory protection capabilities.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] Technical Solution 1: A strain of Lactobacillus plantarum (Lactiplantibacillus plantarum) JS211 that produces extracellular polysaccharides was deposited in the Guangdong Provincial Microbiological Culture Collection Center on August 30, 2024, with the deposit number GDMCC No: 65078.

[0007] Technical solution 2: Application of the Lactobacillus plantarum JS211 in the production of extracellular polysaccharides.

[0008] Technical solution three: An extracellular polysaccharide, which is extracted from the fermentation broth of the plant lactobacillus JS211. The extracellular polysaccharide has a molecular weight of 10-40 kDa and is composed of seven sugars, including glucose, mannose, galactose, galactosamine hydrochloride, glucuronic acid, glucosamine hydrochloride and arabinose.

[0009] Technical solution 4: A method for producing extracellular polysaccharides using the plant lactobacillus JS211, comprising the following steps: fermenting and culturing the plant lactobacillus JS211, concentrating by rotary evaporation, alcohol precipitation, protein removal, secondary alcohol precipitation, dialysis and freeze-drying to obtain the obtained product.

[0010] Furthermore, the fermentation culture condition is fermentation at 37°C for 24 hours.

[0011] Furthermore, the rotary evaporation concentration is concentrated to one fifth of the original volume.

[0012] Technical Solution 5: Extracellular polysaccharide prepared by the method described above.

[0013] Technical Solution 6: Use of the extracellular polysaccharide in the preparation of antioxidant and / or anti-inflammatory drugs.

[0014] The present invention discloses the following technical effects:

[0015] The present invention isolates and identifies a strain of Lactobacillus plantarum (Lactiplantibacillus plantarum) JS211 producing extracellular polysaccharides from Hanzhong slurry, which has been deposited in the Guangdong Provincial Microbial Culture Collection Center on August 30, 2024, with a deposit number of GDMCC No: 65078. The present invention identifies the carbohydrate metabolism of Lactobacillus plantarum JS211, and the results show that there are 23 kinds of carbohydrates that can be metabolized by the strain. The extracellular polysaccharide extracted by the method of the present invention is a fibrous white loose solid substance with a yield of 302 mg / L and a sugar content of 91.2%. In addition, the present invention uses a water extraction and alcohol precipitation method to extract extracellular polysaccharides from the fermentation broth of Lactobacillus plantarum JS211, and further verifies the scavenging ability of the extracellular polysaccharide on DPPH and ABTS free radicals and explores its anti-inflammatory ability by gavage in mice with DSS-induced colitis. The results show that the extracellular polysaccharide prepared from the fermentation broth of Lactobacillus plantarum JS211 of the present invention has antioxidant and / or anti-inflammatory protection capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 The colony morphology (A) and Gram staining image (B) of Lactobacillus plantarum JS211;

[0018] Figure 2 This is the result of the alignment of the rRNA sequence of Lactobacillus plantarum JS21116S;

[0019] Figure 3 is the growth curve of Lactobacillus plantarum JS211;

[0020] Figure 4 is the glucose standard curve;

[0021] Figure 5 It is the extracellular polysaccharide purified from Lactobacillus plantarum JS211; wherein A is the extracellular polysaccharide image obtained by the traditional extraction method; B is the extracellular polysaccharide image obtained by the scheme of the present invention;

[0022] Figure 6 The structure of the extracellular polysaccharide of Lactobacillus plantarum JS211 under a scanning electron microscope; A: 2000 times magnification; B: 5000 times magnification; C: 10000 times magnification;

[0023] Figure 7 HPGPC chromatogram for molecular weight detection of Lactobacillus plantarum JS211 exopolysaccharide;

[0024] Figure 8 HPGPC chromatogram for detection of monosaccharide composition of Lactobacillus plantarum JS211 exopolysaccharide;

[0025] Fig. 9 The scavenging ability of Lactobacillus plantarum JS211 extracellular polysaccharide on DPPH and ABTS free radicals;

[0026] Fig.10 H&E staining of mouse colon tissue, where A is the control group; B is the model group; C is the low-dose EPS group; and D is the high-dose EPS group. DETAILED DESCRIPTION

[0027] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0028] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0029] Example 1 Isolation and identification of strains

[0030] (1) Isolation of strains

[0031] Samples were collected on the 1st, 5th and 10th days of fermentation in Hanzhong. The samples were filtered twice with gauze in a clean bench using aseptic operation to remove coarse residue. The treated samples were mixed and diluted to 10% with physiological saline. -3 , 10 -4 , 10 -5 , 100 μL was spread on MRS agar medium containing 1% CaCO3, and cultured at 37°C for 24 hours. Single colonies that can produce CaCO3 dissolution circles were picked and streaked multiple times on MRS-CaCO3 medium for purification, and the purified single colonies were picked and cultured in MRS liquid medium at 37°C for 24 hours, and stored in a -80°C refrigerator with 15% glycerol.

[0032] (2) Morphological characteristics of strains

[0033] Pick the preserved glycerol bacteria and streak them onto MRS agar medium, incubate at 37°C for 24 hours, pick a single colony and incubate it at 37°C in MRS liquid medium for 24 hours. Observe the color, size, and edge morphology of the colony, observe the bacterial morphology and Gram identification results by Gram staining, and record the colony morphology and microscope staining pictures. Figure 1 As shown, the colony is light yellow, round, opaque, convex, with a smooth and moist surface, shiny, complete edges, G+, and short rod shape.

[0034] (3) 16S rRNA sequencing identification

[0035] The genomic DNA was extracted using a bacterial genomic DNA purification kit. The universal primers 27F: 5'-AGAGTTTGATCCTGGCTCAG-3' (SEQ ID NO. 1) and 1429R: 5'-GGTTACCTTGTTACGACTT-3' (SEQ ID NO. 2) were used to amplify the full-length 16S rRNA sequence of the strain (SEQ ID NO. 3).

[0036] The full-length 16S rRNA sequence of the strain:

[0037]

[0038] The amplification procedure was: 95°C pre-denaturation for 5 min, 30 cycles (95°C denaturation for 1 min, 50°C annealing for 1 min, 72°C extension for 90 s), and 72°C full extension for 10 min. The amplified product was sequenced, and the sequencing results were compared with the NCBI database Blast to confirm the biological classification of the strain. The 16S rRNA identification results showed that the strain had a 100% similarity with Lactobacillus plantarum, and the strain was named Lactobacillus plantarum JS211. The 16S rRNA sequence alignment results of Lactobacillus plantarum JS211 are shown in Figure 2 . Lactobacillus plantarum JS211 was classified and named Lactiplantibacillus plantarum, and was deposited in Guangdong Microbiological Culture Collection Center on August 30, 2024, with the deposit number GDMCC No: 65078.

[0039] (4) The carbohydrate metabolism of Lactobacillus plantarum JS211 was identified, and the results showed that this strain could metabolize 23 types of carbohydrates (see Table 1).

[0040] Table 1 Identification results of carbohydrate metabolism of Lactobacillus plantarum JS211

[0041]

[0042]

[0043] The growth curve of Lactobacillus plantarum JS211 is shown in Figure 3 The results showed that it entered the logarithmic phase at 5 hours and grew rapidly, and entered the stable phase after 16 hours. 600 Up to 4.5.

[0044] Example 2 Extraction of exopolysaccharide from Lactobacillus plantarum JS211

[0045] (1) Experimental Materials

[0046] Sucrose, MRS broth medium (sugar-free), 95% volume ethanol, trichloroacetic acid, dialysis bag (8-14 kDa), high-glucose MRS medium (dissolve 50 g sucrose and 32.24 g MRS broth medium (sugar-free) in water, make up to 1 L, and sterilize at 118°C for 15 min).

[0047] (2) Experimental methods

[0048] Isolation and purification of exopolysaccharides from Lactobacillus plantarum JS211 in the control group and experimental group

[0049] The control group, that is, the steps of the water extraction and alcohol precipitation method of traditional extracellular polysaccharides are: concentration, alcohol precipitation, impurity removal, dialysis, and freeze-drying; the experimental group is the scheme provided by the present invention, and the specific steps are: activating plant lactobacillus twice and then culturing: culturing at 37°C for 24h, then collecting the fermentation supernatant at 7000g / min, then using a rotary evaporator to concentrate the supernatant to one-fifth of the original volume, adding four times the volume of anhydrous ethanol, standing at 4°C overnight and collecting the precipitate, re-dissolving the precipitate with water, adding trichloroacetic acid with a final concentration of 4%, standing at 4°C overnight and collecting the supernatant, adding four times the volume of anhydrous ethanol, standing at 4°C overnight and collecting the precipitate, re-dissolving the precipitate with water and transferring it to a dialysis bag of 8-14kda, dialyzing the dialyzed product with pure water for 24h at 7000g / min15min to remove insoluble matter, and freeze-drying the supernatant to obtain plant lactobacillus extracellular polysaccharides.

[0050] (3) Polysaccharide content detection

[0051] Prepare 0.1 mg / mL glucose solution, use phenol-sulfuric acid method to measure glucose standard curve, and add samples according to Table 2.

[0052] Table 2 Glucose standard curve determination

[0053] Tube No. 1 2 3 4 5 6 7 8 Glucose standard solution (mL) 0 0.1 0.2 0.3 0.4 0.6 0.8 1.0 Distilled water (mL) 2.0 1.9 1.8 1.7 1.6 1.4 1.2 1.0 6% phenol (mL) 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Sulfuric acid (mL) 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0

[0054] During the operation, first add glucose standard solution and distilled water to each tube, then add phenol and concentrated sulfuric acid tube by tube; mix well, let stand at room temperature for 10 minutes, and then stop the reaction in a 30℃ water bath for 15 minutes; measure the absorbance at 490nm, and draw a glucose standard curve with the glucose solution concentration as the horizontal axis and the absorbance at 490nm as the vertical axis; take 10mg of freeze-dried extracellular polysaccharide to prepare a 0.1mg / mL solution, and use the phenol-sulfuric acid method to determine A 490 , substitute the absorbance value into the glucose standard curve to calculate the purity of extracellular polysaccharide. Figure 4 Glucose standard curve. Figure 5 A is a picture of the extracellular polysaccharide obtained by the traditional extraction method of the control group; B is a picture of the extracellular polysaccharide extracted by the scheme of the present invention of the experimental group. It can be seen that the extracellular polysaccharide extracted by the control group is yellowish in color, has pigment deposition, and has a purity of 76.0%. The extracellular polysaccharide extracted by the method of the present invention is a fibrous white loose solid substance with a yield of 302 mg / L and a sugar content of 91.2%.

[0055] Example 2 Physicochemical properties of Lactobacillus plantarum JS211 exopolysaccharide

[0056] (1) The microstructure of the Lactobacillus plantarum JS211 exopolysaccharide extracted from the experimental group in Example 1 was observed by scanning electron microscopy;

[0057] (2) Detection of molecular weight by high performance liquid chromatography: prepare 0.05M NaCl solution, filter through 0.22μm filter membrane, sonicate for 20min, and store at room temperature. Establishment of molecular weight calibration curve: accurately weigh dextran standards of different molecular weights (molecular weight 1000, 5000, 12000, 25000, 50000, 80000, 150000, 270000, 410000, 670000 series analytical standards), add 0.05M NaCl solution to prepare 5mg / mL dextran standard solution, filter through 0.22μm microporous filter membrane for later use, adopt HPGPC method, use high performance gel permeation chromatography tandem column for detection, use the logarithm of relative molecular mass of standard as ordinate, use the retention time of corresponding chromatographic peak as abscissa for linear regression, and obtain calibration curve.

[0058] (3) Preparation of test sample solution: Accurately weigh 5 mg of sample and add 1 ml of 0.05 M NaCl solution to the sample to prepare a 5 mg / ml test sample solution. Centrifuge at 8000 rpm for 10 min, filter the supernatant with a 0.22 μm microporous filter membrane, and then transfer the sample to a 2 ml injection bottle for later use.

[0059] (4) Chromatographic method: HPGPC method was used, and high-performance gel permeation chromatography tandem columns were used for detection. Instrument: Waters high-performance liquid chromatograph; Detector: Waters differential detector; Chromatographic column: 3 polymer-based water-soluble SEC (GFC) chromatographic columns (8×300 mm) connected in series; Mobile phase: 0.05 M NaCl solution; Flow rate: 0.65 ml / min; Column temperature: 40°C; Injection volume: 30 μL.

[0060] (5) Determination of monosaccharide composition by high performance liquid chromatography

[0061] (6) Preparation of standard substances: Weigh 5 mg each of rhamnose, arabinose, galactose, glucose, xylose, mannose, galacturonic acid, glucuronic acid, glucosamine hydrochloride, and galactosamine hydrochloride monosaccharides and 10 mg of fucose in sequence, dissolve them and make up to 10 ml in a volumetric flask to prepare the standard substance mother solution. Then dilute them to the following gradient dilutions, filter through a 0.22 μm microporous membrane, and place in a sample injection bottle.

[0062] Table 3 Monosaccharide mixed standard gradient concentration information

[0063]

[0064] (7) Preparation of test sample solution

[0065] Solid sample extraction: Take a clean chromatographic bottle, accurately weigh 5 mg (± 0.05 mg) of polysaccharide sample, add 1 mL of 2M TFA acid solution, and heat at 121°C for 2 hours. Pass nitrogen and blow dry. Add 3 mL of methanol to wash, blow dry again, and repeat the methanol washing 2-3 times. Add 5 mL of sterile water to dissolve, and transfer to a chromatographic bottle for testing. Liquid sample extraction Take an appropriate amount of supernatant, rotate and concentrate or blow dry with nitrogen. Add 1 mL of 2M TFA solution, and heat at 121°C for 2 hours. Pass nitrogen and blow dry. Add methanol to wash, blow dry again, and repeat the methanol washing 2-3 times. Add sterile water to dissolve, and transfer to a chromatographic bottle for testing.

[0066] (8) PMP derivatization: Take 0.2 mL of monosaccharide standard solution or polysaccharide hydrolyzate in a stoppered conical centrifuge tube, add 0.2 mL of 0.5 mol / L sodium hydroxide solution and 0.5 mL of 0.5 mol / L PMP methanol solution, vortex mix well and react in a 70°C water bath for 1 h. After the reaction is completed, add 0.2 mL of 0.5 mol / L hydrochloric acid to neutralize the added sodium hydroxide. Add 1 mL of chloroform and vortex extract three times to remove excess PMP. After discarding the chloroform layer, take 0.3 mL and add water to make up to 1 mL.

[0067] (9) Chromatographic method: ThermoU3000 liquid chromatography system, ZORBAX EclipseXDB-C18 column, acetonitrile: phosphate buffer (12 g / L potassium dihydrogen phosphate, 2 M NaOH to adjust pH to 6.8) mobile phase, isocratic elution, volume ratio of acetonitrile to phosphate buffer was 17:83, flow rate was 0.8 ml / min, column temperature was 30 °C, detection wavelength was 250 nm, injection volume was 10 μL.

[0068] (10) Experimental results

[0069] The extracellular polysaccharides of Lactobacillus plantarum JS211 appeared as irregular flakes or debris accumulations under scanning electron microscopy, with a rough surface and small spherical structures. The molecular weight was between 10-40 kDa and it was composed of seven sugars, including glucose, mannose, galactose, galactosamine hydrochloride, glucuronic acid, glucosamine hydrochloride and arabinose, accounting for 45.909%, 26.557%, 7.854%, 7.701%, 6.379%, 5.466% and 0.134% respectively. Figure 6 The structure of the extracellular polysaccharide of Lactobacillus plantarum JS211 under a scanning electron microscope; A: 2000 times magnification; B: 5000 times magnification; C: 10000 times magnification; Figure 7 HPGPC chromatogram for molecular weight detection of Lactobacillus plantarum JS211 exopolysaccharide; Figure 8 HPGPC chromatogram for detecting the monosaccharide composition of the extracellular polysaccharide of Lactobacillus plantarum JS211.

[0070] Example 3 Determination of the Antioxidant Capacity of Extracellular Polysaccharides of Lactobacillus plantarum JS211

[0071] (1) Experimental Materials

[0072] The Lactobacillus plantarum JS211 extracellular polysaccharide extracted from the experimental group in Example 1, the total antioxidant capacity (T-AOC) detection kit, and the total antioxidant capacity (T-AOC) detection kit.

[0073] (2) Experimental methods

[0074] Use DPPH free radical scavenging ability assay kit. Preheat the multifunctional microplate reader for 30 minutes and set the wavelength to 515nm. Set up a control group and an experimental group. The sample concentration of the experimental group is 1mg / mL. React in an EP tube. Add 20μL of extract and 380L of reagent 1 to the blank tube. Add 20μL of sample and 380μL of reagent 1 to the assay tube. Perform three parallel tests. Mix thoroughly, react at room temperature in the dark for 20 minutes, and take 200μL to a 96-well plate to measure the absorbance at 515nm.

[0075] DPPH free radical scavenging rate (%) = (A empty - A test) ÷ A empty * 100%

[0076] Wherein, Ablank and Ameasured are the absorbance values ​​of the blank tube and the measuring tube at 515 nm respectively.

[0077] Determination of ABTS free radical scavenging ability; Use ABTS free radical scavenging ability assay kit. Preheat the multifunctional microplate reader for 30 minutes, set the wavelength to 734nm; Add 10μL of extract and 190μL of working solution to the blank tube; Add 10μL of sample (1mg / mL) and 190μL of working solution to the assay tube; Mix thoroughly, let stand for 20 minutes, and take 200μL of supernatant to a 96-well plate to measure the absorbance at 734nm. Calculate the superoxide anion free radical scavenging rate, and perform 3 parallel tests.

[0078] ABTS free radical scavenging rate (%) = (A blank - A test) ÷ A blank * 100%

[0079] Wherein, Ablank and Ameasured are the absorbance values ​​of the blank tube and the measuring tube at 734 nm respectively.

[0080] (3) Experimental results

[0081] The results show that the extracellular polysaccharide of Lactobacillus plantarum JS211 has a good scavenging ability for ABTS free radicals, with a scavenging rate of 90.5%, and a scavenging ability for DPPH free radicals of about 20.1%. This shows that the extracellular polysaccharide of Lactobacillus plantarum JS211 prepared by the present invention has a good antioxidant capacity. Fig. 9The scavenging ability of Lactobacillus plantarum JS211 extracellular polysaccharide on DPPH and ABTS free radicals.

[0082] Example 4 Protective ability of Lactobacillus plantarum JS211 exopolysaccharide (EPS) against DSS-induced colitis in mice

[0083] (1) Grouping: Six-week-old C57BL / 6N mice were divided into four groups, with 10 mice in each group: control group (no treatment); model group (3% dextran sulfate sodium salt (DSS)); low-dose EPS group (50 mg / kg EPS); high-dose EPS group (250 mg / kg EPS).

[0084] (2) Mouse culture: W1: All mice were cultured for one week without treatment; W2: The drinking water of groups ① and ② was purified water, and they were gavaged with purified water once a day; the drinking water of groups ③ and ④ was purified water, and they were gavaged with the corresponding concentration of EPS once a day; W3: The drinking water of group ① was purified water, and they were gavaged with purified water; the drinking water of group ② was 3% DSS solution, and they were gavaged with purified water solution once a day; the drinking water of groups ③ and ④ was 4% DSS solution, and they were gavaged with the corresponding concentration of EPS once a day. The weight, food weight and drinking water weight of mice were tested daily, and the shape of feces and whether there was blood in the stool were observed. The daily changes in weight, food intake and water intake were recorded, and the DAI value was calculated according to the DAI scoring standard. That is, DAI = (body mass index + stool shape + bleeding) / 3.

[0085] (3) Sample collection: On the 22nd day of the experiment, the mice were killed and the following samples were collected:

[0086] ① Organs: dissect and separate the spleen, liver and thymus of mice, remove the surface fascia, absorb the blood with filter paper, weigh the wet weight, and calculate the corresponding organ index.

[0087] Organ index = organ mass (mg) / body weight (g)

[0088] ② Colon: After killing the mice, dissect the mice, remove the colon, place it on coordinate paper, measure the length and record it.

[0089] ③ Serum: The eyeball was enucleated to obtain blood. The blood was placed in a 37°C water bath for 1 hour and then placed in a 4°C refrigerator for 2 hours. The blood was centrifuged at 3000 r / min for 10 minutes, and the supernatant was collected, aliquoted, and stored at -80°C for ELASA testing.

[0090] (4) Experimental results

[0091] Compared with the control group, the mice in the model group showed decreased food intake, weight loss, bloody stools and amorphous feces, and the DAI score was greater than 2. Fig.10H&E staining of mouse colon tissue, where A is the control group; B is the model group; C is the low-dose EPS group; and D is the high-dose EPS group. After H&E staining of colon tissue, it was observed that the colon tissue structure was severely damaged, the goblet cells were destroyed, and the crypt structure was missing, indicating that the modeling was successful. Compared with the model group, the food intake of the EPS gavage group increased to a certain extent, and the weight loss was slowed down. H&E staining of colon tissue found that the goblet cells were relatively intact, the crypt structure was significantly restored, and the recovery degree of the high-dose group was higher. This shows that EPS has anti-inflammatory and protective abilities against DSS-induced colitis mice.

[0092] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A strain of Lactobacillus plantarum JS211 producing extracellular polysaccharides, characterized in that: It was deposited in Guangdong Provincial Microbiological Culture Collection Center on August 30, 2024, with the deposit number GDMCC No: 65078.

2. Use of Lactobacillus plantarum JS211 according to claim 1 in producing exopolysaccharides.

3. An extracellular polysaccharide, characterized in that The extracellular polysaccharide is extracted from the fermentation broth of Lactobacillus plantarum JS211 according to claim 1, and the extracellular polysaccharide includes glucose, mannose, galactose, galactosamine hydrochloride, glucuronic acid, glucosamine hydrochloride and arabinose, with the proportions being 45.9%, 26.6%, 7.6%, 7.7%, 6.4%, 5.5% and 0.1% respectively.

4. A method for producing exopolysaccharides using Lactobacillus plantarum JS211 according to claim 1, characterized in that: The following steps are involved: The plant lactobacillus JS211 is subjected to fermentation culture, rotary evaporation concentration, alcohol precipitation, protein removal, secondary alcohol precipitation, dialysis and freeze-drying to obtain the product.

5. The method according to claim 4, characterized in that The fermentation culture conditions are fermentation at 37° C. for 24 hours.

6. The method according to claim 4, characterized in that The rotary evaporation concentration is to concentrate to one fifth of the original volume.

7. Extracellular polysaccharide prepared by the method according to any one of claims 4 to 6.

8. Use of the extracellular polysaccharide according to claim 7 in the preparation of anti-oxidative and / or anti-inflammatory drugs.

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