A Lactobacillus ginkgo and its application

Abstract

The present invention provides a Lactobacillus ginkgo cqf-43, whose Latin name is Lactiplantibacillus artgentoratensis cqf‑43 , which was deposited at the Guangdong Microbial Culture Collection Center on May 12, 2022, with the deposit registration number of GDMCC 62463. This strain was isolated from the feces of healthy sows and has good lactic acid production ability, exopolysaccharide production ability, good tolerance to the gastrointestinal tract, and certain high-temperature tolerance ability; the fermentation supernatant and fermentation broth of this strain have good antioxidant ability; this strain can promote animal growth and improve animal intestinal health; the exopolysaccharide produced by this strain has good antioxidant activity.

Description

Technical Field

[0001] The present invention relates to the field of microorganisms, and particularly to Lactiplantibacillus artgentoratensis and its applications. Background Art

[0002] As an important probiotic, lactic acid bacteria are widely used in fields closely related to human life such as industry, agriculture and animal husbandry, medicine and food. They can play important physiological roles in the body by producing antibacterial substances, maintaining the balance of intestinal flora, enhancing the body's immunity, etc., and have a good history of safe application, becoming the focus of probiotic research at home and abroad. Exopolysaccharide (EPS) of lactic acid bacteria is a water-soluble macromolecular carbohydrate secreted by lactic acid bacteria during the process of reproduction and metabolism. The characteristics of EPS are mainly reflected in the following two aspects. One is the physicochemical characteristics, which can improve the rheology, texture, stability, water-holding capacity and taste of food, etc.; the other is the biological activity, and EPS has physiological functions such as anti-tumor, antioxidant, immunomodulatory, cholesterol-lowering, blood sugar-lowering, blood lipid-lowering, anticoagulant, and protecting intestinal health.

[0003] At present, the application of EPS is mainly as a food additive added to food, or directly produced by lactic acid bacteria in fermented foods, and widely used in the pharmaceutical industry as drugs and health foods, while its development and application in livestock and poultry breeding are very scarce. Most of the lactic acid bacteria producing EPS are derived from dairy products such as yogurt, cheese and Kefir products, and some are from fermented meat products and vegetables, while there are few research reports on lactic acid bacteria producing EPS from animal sources. Summary of the Invention

[0004] The purpose of the present invention is to provide a new Lactiplantibacillus artgentoratensis, which has good tolerance to the animal gastrointestinal tract, can secrete metabolites with strong antioxidant properties, and can improve the intestinal health of animals.

[0005] The purpose of the present invention is achieved by the following measures:

[0006] A Lactiplantibacillus artgentoratensis cqf-43, with its Latin name Lactiplantibacillus artgentoratensis cqf-43, was deposited at the Guangdong Provincial Culture Collection of Microorganisms on May 12, 2022, with the deposit registration number GDMCC 62463, simply referred to as cqf-43. This strain was isolated from the feces of healthy sows, has good lactic acid-producing ability and exopolysaccharide-producing ability, has good tolerance to the gastrointestinal tract, and certain high-temperature tolerance ability; the fermentation supernatant and fermentation broth of this strain have good antioxidant ability; this strain can promote animal growth and improve the intestinal health of animals; the exopolysaccharide produced by this strain has good antioxidant activity.

[0007] Application of the above strain as a fermentation inoculant in fermentation products.

[0008] Another object of the present invention is to provide a derivative product of the above Lactobacillus ginkgo.

[0009] A product for regulating intestinal flora, the active ingredient of which is the above Lactobacillus ginkgo cqf-43 and / or its metabolites.

[0010] An antioxidant, the main ingredient of which is the fermentation broth or fermentation supernatant of Lactobacillus ginkgo cqf-43. Preferably, the main ingredient is the exopolysaccharide produced by the fermentation of Lactobacillus ginkgo cqf-43.

[0011] The present invention provides the application of the above strain in feed. It has significant advantages especially in liquid feed.

[0012] A feed containing the above bacteria and / or their metabolites.

[0013] The above feed has a pH of 3-4, contains acid-soluble protein > 2.3%, crude protein > 22.1, soluble sugar > 14.7, and soluble protein > 16.8.

[0014] The above feed uses a pulverized corn-soybean meal-wheat bran mixture as the fermentation substrate, and the strain inoculation amount is 2%.

[0015] The preparation method of the above feed is to mix the fermentation substrate with the bacteria, add water and mix evenly. Finally, the water-to-feed ratio is 3:1, seal it, ferment at 30°C for 24 hours.

[0016] Beneficial effects

[0017] 1. A strain of Lactobacillus ginkgo was isolated from the feces of healthy sows in the present invention. It has good lactic acid production ability, exopolysaccharide production ability, has good tolerance to the gastrointestinal tract, and certain high-temperature tolerance ability; this strain can improve animal intestinal health, protect the intestine, and promote animal growth, especially has excellent effects on maintaining and repairing the gastrointestinal health of pigs.

[0018] 2. The fermentation supernatant and fermentation broth of the strain provided by the present invention have good antioxidant ability; the exopolysaccharide produced has good antioxidant activity.

[0019] 3. This strain can be used for fermenting feed. After the feed is liquid-fermented by Lactobacillus ginkgo cqf-43, the feed has an acid fragrance, the pH value is significantly reduced, and the contents of acid-soluble protein and soluble protein that are easy to absorb in the feed are significantly increased, improving the digestion and absorption efficiency of the feed. Description of the drawings

[0020] Figure 1 Morphology of Lactobacillus ginkgo cqf-43: Figure 1-1For colony morphology, Figure 1-2 For cell morphology.

[0021] Figure 2 Phylogenetic tree of Lactobacillus ginkgo cqf-43

[0022] Figure 3 Curves of lactic acid and exopolysaccharide production by Lactobacillus ginkgo cqf-43

[0023] Figure 4 Free radical scavenging activity of Lactobacillus ginkgo cqf-43

[0024] Figure 5 Free radical scavenging activity of the polysaccharide produced by Lactobacillus ginkgo cqf-43

[0025] Figure 6 Effect of Lactobacillus ginkgo cqf-43 on the growth performance of SD rats

[0026] Figure 7 Preventive effect of Lactobacillus ginkgo cqf-43 on colitis

[0027] Figure 8 Comparison of sedimentation between the fermentation group and the control group of Lactobacillus ginkgo cqf-43 Detailed implementation manners

[0028] The following are specific implementation examples for specifically describing the present invention. It is pointed out here that the following implementation examples are only used for further illustration of the present invention and should not be construed as limiting the protection scope of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention according to the above-mentioned invention content.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the relevant art.

[0030] Example 1 Isolation and identification of strains

[0031] 1.1 Isolation of strains

[0032] MRS liquid medium: 10 g of peptone, 10 g of beef extract, 20 g of glucose, 5 g of yeast powder, 5 g of sodium acetate, 2 g of diammonium citrate, 2 g of dipotassium hydrogen phosphate, 0.25 g of manganese sulfate heptahydrate, 0.58 g of magnesium sulfate heptahydrate, 1 mL of Tween 80, made up to 1 L with distilled water, pH 6.5, sterilized at 115 °C for 20 min; MRS solid medium is prepared by adding 1.5% - 2.0% (w / v) agar powder to the liquid medium.

[0033] Take 2.5 g of feces from healthy sows and place it in 22.5 mL of sterilized physiological saline with a concentration of 0.9% by mass. Use the ten-fold dilution method to perform gradient dilution on the sample, and then coat it on MRS agar plate medium (a product sold by OXID company). Incubate at 37 °C for 48 h to 72 h, observe the cell morphology, pick single colonies with viscous filaments and inoculate them on MRS solid medium plates for continued cultivation. After repeated streak cultivation and purification on MRS solid medium plates, multiple strains of pure-cultured bacteria are obtained. One of them is named strain cqf-43.

[0034] 1.2 Identification of strains

[0035] The colony morphology of strain cqf-43 is shown in Figure 1 , which is a round, milky white colony with a convex middle, and has a capsule on the outer layer and can be drawn into filaments when picked up. The photo under an optical microscope is shown in Figure 2 , the Gram stain is purple-red, and the bacterial cells are short rod-shaped, mostly single, paired or in cell chains.

[0036] The identification result of API 50CH (bioMérieux, France) shows that strain cqf-43 is Lactobacillus plantarum. Strain cqf-43 can utilize: glycerol, L-arabinose, D-ribose, D-galactose, D-glucose, D-fructose, D-mannose, D-mannitol, sorbitol, methyl-α-D-mannopyranoside, N-acetylglucosamine, amygdalin, arbutin, esculin ferric citrate, salicin, D-cellobiose, D-maltose, D-lactose, D-melibiose, D-sucrose, D-trehalose, D-melezitose, D-raffinose, D-gentiobiose, D-turanose, potassium gluconate; those that cannot be utilized are: erythritol, D-arabinose, D-xylose, L-xylose, D-ribitol, methyl-β-D-xylopyranoside, L-sorbose, L-rhamnose, dulcitol, inositol, methyl-α-D-glucopyranoside, inulin, starch, glycogen, xylitol, D-lyxose, D-tagatose, D-fucose, L-fucose, D-arabitol, L-arabitol, 2-ketogluconic acid potassium, 5-ketogluconic acid potassium.

[0037] Through 16s PCR amplification and sequencing of cqf-43 as shown in SED ID NO.1, and comparison on https: / / www.ezbiocloud.net / , the phylogenetic tree constructed by MEGA software is shown in Figure 2 , the comparison result shows that this strain is Lactobacillus plantarum subsp. Lactobacillus ginkgoidies, which is consistent with the identification result of API 50CH (bioMérieux, France), and this strain can be basically identified as Lactobacillus ginkgoidies.

[0038] Example 2 Acid production and exopolysaccharide production ability of the strain

[0039] Pick a single colony of cqf-43 into 25 mL of MRS liquid medium and culture overnight; inoculate 1% into the secondary seed liquid, and sample at 0, 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 27, 30, 33, 36, 39, 42, 45, 48 h of culture. Among them, take 3 tubes at 16, 20, 24, 30, 33, 36, 42, 45, 48 h to detect lactic acid, polysaccharide and OD600 respectively, and take 1 tube at the remaining time points to measure OD600.

[0040] Detection method of OD600: Centrifuge at 8000 r / min for 10 min, discard the supernatant, wash the precipitate twice with normal saline, measure the OD value at 600 nm of absorbance, and draw the growth curve of the strain;

[0041] Detection of lactic acid: Centrifuge the bacterial solution at 8000 r / min for 10 min, take 2 mL of the supernatant into a 10 mL colorimetric tube, heat it in a water bath at 100 °C for 10 min, add 0.2 mL of 50% (volume fraction) H2SO4 and mix well, add 1 mL of methanol, heat it in a water bath at 58 °C for 30 min, then add 1 mL of water, add 2 mL of chloroform, shake for 3 min, centrifuge at 1000 r / min for 2 min, and take the chloroform layer for analysis; analyze by gas chromatography to obtain the lactic acid content.

[0042] Detection of polysaccharide content: Take 2 mL of the bacterial solution into a centrifuge tube, centrifuge at 12500 r / min for 5 min, take 1.5 mL of the supernatant into an EP tube, add 80% trichloroacetic acid to the fermentation supernatant, and the final concentration of trichloroacetic acid is 4%. Place it in a refrigerator at 4 °C overnight, centrifuge after removing proteins (8000 r / min, 4 °C, 15 min) to take the supernatant, add 3 volumes of absolute ethanol and place it in a refrigerator at 4 °C overnight to precipitate polysaccharides; dissolve the precipitate part with 5 mL of water, dialyze with deionized water for 48 h, dilute and make up the volume of the dialyzed liquid to 10 mL, and then determine the polysaccharide content by the phenol-sulfuric acid method.

[0043] Take 10 mg of glucose and prepare a standard solution with a concentration of 100 μg / mL in 100 mL. Take 2.5 g of phenol and prepare a 5% (mass / volume) phenol solution in 50 mL (prepare it freshly before use). Respectively pipette 0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2 mL of the glucose standard solution into 7 10-mL stoppered test tubes, then add water to each test tube to make up to 2 mL, and then add 1.0 mL of 5% phenol solution and 5 mL of concentrated sulfuric acid respectively. After stoppering, let it stand for 20 min. Finally, heat each test tube in a boiling water bath for 15 min, then take it out and cool for 20 min, and measure the absorbance at a wavelength of 490 nm. Measure the solution in each test tube 3 times and take the average value. Finally, use the glucose concentration as the abscissa and the absorbance as the ordinate to establish a glucose standard curve. Treat the polysaccharide sample according to the above method, and calculate the polysaccharide concentration (calculated as glucose) from the standard curve.

[0044] It can be seen from Figure 3 that under static culture at 30 °C and inoculated at an inoculation amount of 1%, the strain reaches the stationary phase after 22 h. At the end of the stationary phase, the product accumulation of the strain is the most, and the highest lactic acid production can reach 43.40 g / L, and the highest polysaccharide production can reach 0.3 g / L.

[0045] Example 3 Inhibitory effect of the strain on common pathogenic bacteria

[0046] Nutrient broth (NB): 10.0 g of peptone, 3.0 g of beef extract powder, 5.0 g of sodium chloride, made up to 1 L with distilled water, pH value 7.2 ± 0.2, sterilized at 121 °C for 20 min; NB solid medium is prepared by adding 1.5% - 2.0% (w / v) agar powder to the liquid medium.

[0047] MH agar medium: 6.0 g of beef powder, 1.5 g of soluble starch, 17.5 g of acid hydrolysate of casein, 17.0 g of agar, made up to 1 L with distilled water, pH value 7.3 ± 0.1, sterilized at 121 °C for 20 min.

[0048] Pick a single colony of cqf-43 into 25 mL of MRS liquid medium and culture overnight; take 1% and inoculate it into the secondary seed liquid, culture for 20 h, centrifuge at 8000 r / min for 10 min, and take the supernatant for standby.

[0049] Respectively pick single colonies of ATCC25922 (Escherichia coli), ATCC25923 (Staphylococcus aureus) and CVCC534 (Salmonella pullorum) and inoculate them into NB liquid medium, culture for 12 - 14 h. When the MH agar cools to about 40 °C, add 0.1% of the cultured bacterial liquid, mix well, pour the plate, and set aside for standby.

[0050] Use a punch to make holes in the MH plate. Add 100 μL into the holes, place it upright overnight. After the supernatant is completely absorbed, incubate it upside down for 16 h, observe the inhibition zone, and measure the size of the inhibition zone.

[0051] Table 1 Antibacterial Activity of Lactobacillus ginkgo cqf-43 against Common Pathogenic Bacteria

[0052]

[0053] Example 4 Tolerance Test of Strains

[0054] Preparation method of PBS buffer solution with pH 7.4: 8 g of NaCl, 0.2 g of KCl, 1.42 g of Na2HPO4, 0.27 g of K2HPO4, add water to make up to 1 L, and adjust to pH 7.4 with concentrated hydrochloric acid.

[0055] Pick a single colony of cqf-43 into 25 mL of MRS liquid medium and culture it overnight; take 1% and inoculate it into the secondary seed liquid, culture for 20 h, centrifuge at 8000 r / min for 10 min, pour out the supernatant, wash it 2 times with an equal volume of PBS, add an equal volume of PBS, and mix well for standby.

[0056]

[0057] Note: N1 represents the viable cell count after strain treatment

[0058] N0 represents the viable cell count before strain treatment

[0059] 1. Temperature Tolerance Ability of Strains

[0060] Take 0.5 mL of the bacterial suspension and add it to 4.5 mL of PBS, mix well, and place it in a water bath at 37 °C, 45 °C, 55 °C, 65 °C, 75 °C, and 85 °C for 30 min respectively, then dilute and count. As shown in Table 2, Lactobacillus ginkgo cqf-43 has a certain tolerance to high temperature. After treatment at 65 °C for 30 min, there is still a survival rate of 58.86%, which can facilitate the production of fermentation inoculants.

[0061] Table 2 Temperature Tolerance of Lactobacillus ginkgo cqf-43 (%)

[0062]

[0063] 2. Tolerance Ability of Strains to Bile Salt and Acid

[0064] Take 0.5 mL of the bacterial suspension and add it to 4.5 mL of PBS solutions with pH = 7.4, pH = 2, pH = 3, and bile salt concentrations of 0.3% and 0.6% respectively. Dilute and count the samples at 2H and 4H respectively. As can be seen from Table 3, Lactobacillus ginkgo cqf-43 has good tolerance to both bile salts and acids.

[0065] Table 3 Tolerance of Lactobacillus ginkgo cqf-43 to bile salts and pH (%)

[0066]

[0067] 3. Tolerance of the strain to gastrointestinal fluids

[0068] Artificial gastric juice: Take 16.4 mL of dilute hydrochloric acid (dilute 234 mL of concentrated hydrochloric acid to 1000 mL with water to obtain 9.5 - 10.5% dilute hydrochloric acid), add about 800 mL of water and 10 g of pepsin, shake well, and then dilute with water to 1000 mL.

[0069] Artificial intestinal juice: Take 250 mL of 0.2 mol / L potassium dihydrogen phosphate solution, add 118 mL of 0.2 mol / L sodium hydroxide solution. Separately, dissolve 10 g of pancreatin and 18 g of porcine bile salt in an appropriate amount of water. Mix the two solutions and then dilute with water to 1000 mL, shake well.

[0070] Simulated gastric juice tolerance test: Take 1 mL of each test bacterial suspension and add it to 9 mL of artificial gastric juice. Incubate in a water bath at 37°C for 3 h, and measure the viable cell count at 0, 1, 2, and 3 h. Each sample has 3 parallels. Calculate the survival rate based on the viable cell count.

[0071] Simulated intestinal juice tolerance test: Pipette 1 mL of the test bacterial suspension and add it to 9 mL of simulated intestinal juice. Continue to incubate in a water bath at 37°C, and measure the viable cell count at 0, 1, 2, and 3 h. Each sample has 3 parallels. Calculate the survival rate based on the viable cell count.

[0072] As can be seen from Table 4, cqf-43 still has a survival rate of 38.77% after being treated in artificial gastric juice for 3 h, and the survival rate can reach 79.69% after being treated in artificial intestinal juice for 3 h, indicating that cqf-43 has a certain tolerance to gastrointestinal fluids and can survive in the animal body by passing through the gastrointestinal fluids.

[0073] Table 4 Tolerance of Lactobacillus ginkgo cqf-43 to gastrointestinal fluids (%)

[0074]

[0075] Example 5 Antioxidant activity of the strain

[0076] Vitamin C solution (VC): Before use, prepare a 0.15 mg / mL vitamin C solution with deionized water as the solvent. And dilute it into different gradients.

[0077] Full fermentation culture: The fermentation stock solution cultured for 33 h was serially diluted with sterile water to an appropriate gradient and reserved.

[0078] Fermentation supernatant: The full fermentation culture cultured for 33 h was centrifuged at 4 °C and 8000 r / min for 15 min, and the supernatant collected was the fermentation supernatant. The fermentation supernatant was serially diluted with sterile water to an appropriate gradient and reserved.

[0079] 1. Determination of DPPH free radical scavenging rate

[0080] Take 1 mL of DPPH solution (0.15 mmol / L) and mix it with 1 mL of sample solution. Let it stand in the dark at room temperature (25 °C) for 30 min, and measure the absorbance A1 of the mixture at a wavelength of 517 nm. After mixing 1 mL of sample solution with 1 mL of 95% ethanol, measure its absorbance A2. After mixing 1 mL of ultrapure water with 1 mL of DPPH ethanol (95%), measure its absorbance A3. The formula for calculating the DPPH scavenging rate is:

[0081] DPPH free radical scavenging rate = [1 - (A1 - A2) / A3] × 100%

[0082] 2. Determination of ABTS free radical scavenging rate

[0083] Dilute the ABTS mother liquor with 0.2 mol / L PBS buffer solution at pH 7.4 to make its absorbance value at a wavelength of 734 nm be 0.7 ± 0.02. Pipette 1 mL of sample solution and 3 mL of ABTS solution into a colorimetric tube and mix well. After reacting in the dark at room temperature for 6 min, measure the absorbance value (A1) at a wavelength of 734 nm.

[0084] Use the reaction system with 1 mL of ultrapure water instead of the sample as the control group (A2), use the reaction system with 3 mL of PBS instead of the ABTS solution as the sample blank group (A3), and use the reaction system with 1 mL of ultrapure water and 3 mL of PBS buffer solution instead of the sample and ABTS solution respectively as the blank group (A4).

[0085] ABTS free radical scavenging rate = [1 - (A1 - A3) / (A2 - A4)] × 100%

[0086] It can be seen from Figure 4 that the full fermentation culture and fermentation supernatant of Lactobacillus ginkgo cqf-43 have strong scavenging activities against free radicals. When diluted to 31.25 μL / mL, the DPPH free radical scavenging rate and ATBS free radical scavenging rate of the full fermentation culture and fermentation supernatant both reach more than 90%.

[0087] Antioxidant activity of exopolysaccharides produced by the strain in Example 6

[0088] The fully fermented culture incubated for 33 h was centrifuged at 8,000 r / min for 15 min at 4°C. The precipitate was discarded, and the supernatant was collected. 80% trichloroacetic acid was added to the supernatant, and the final concentration of trichloroacetic acid was 4%. It was placed in a refrigerator at 4°C overnight. After removing proteins, it was centrifuged (8,000 r / min, 4°C, 15 min), and the supernatant was taken. Three volumes of absolute ethanol were added, and it was placed in a refrigerator at 4°C overnight to precipitate polysaccharides. The precipitated part was redissolved in 10 mL of water to obtain a solution, and the solution was freeze-dried to obtain crude polysaccharides.

[0089] The crude polysaccharides were formulated into a 10 mg / mL solution with sterile water and serially diluted into appropriate gradients to measure the DPPH free radical scavenging rate and ATBS free radical scavenging rate of the crude polysaccharide solution.

[0090] It can be seen from Figure 5 that the exopolysaccharides produced by Lactobacillus ginkgo cqf-43 have good antioxidant activity.

[0091] Growth-promoting effect of the strain in Example 7

[0092] Animals: 18 clean 5-week-old SD rats were divided into two groups, with 9 rats in each group, and the following treatments were carried out respectively:

[0093] Experimental group: Lactobacillus ginkgo cqf-43 bacterial solution (volume 2 mL, containing 2×10 10 cfu of Lactobacillus ginkgo cqf-43, with the solvent being 0.9% normal saline) was gavaged once every other day for 30 consecutive days.

[0094] Control group: 2 mL of 0.9% normal saline was gavaged once every other day for 30 consecutive days. The weight, food intake, and feed-to-weight ratio of the SD rats were observed by weighing every 7 days.

[0095] It can be seen from Figure 6 that the average daily weight gain of SD rats gavaged with Lactobacillus ginkgo cqf-43 was significantly higher than that of the control group gavaged with normal saline, and the feed-to-weight ratio was significantly lower than that of the control group, showing a certain growth-promoting effect.

[0096] Intestinal protection effect of the strain in Example 8

[0097] Animals: 14 clean 3-week-old SD rats were divided into two groups, with 7 rats in each group, and the following treatments were carried out respectively:

[0098] Experimental group: Lactobacillus ginkgo cqf-43 bacterial solution (volume 2 mL, containing 2×10 10cfu of Lactobacillus ginkgo cqf-43, with the solvent being 0.9% normal saline), after continuous gavage for 21 days, the drinking water was changed to 4% DSS solution. After drinking for 4 days, the animals were sacrificed, the intestinal segments and colon length were measured, and the colon morphology was observed.

[0099] Control group: Gavage once every other day, with a volume of 2 mL of 0.9% normal saline. After continuous gavage for 21 days, the drinking water was changed to 4% DSS solution. After drinking for 4 days, the animals were sacrificed, the intestinal segments and colon length were measured, and the colon morphology was observed.

[0100] It can be seen from Figure 7 that the colon length of SD rats gavaged with Lactobacillus ginkgo cqf-43 was significantly higher than that of the control group, and the apparent hyperemia was also milder than that of the control group, indicating that Lactobacillus ginkgo cqf-43 has a good protective effect on intestinal damage caused by DSS.

[0101] Application of the strain in fermented feed in Example 9

[0102] Pick a single colony of cqf-43 and inoculate it into 25 mL of MRS liquid medium and culture overnight; take 1% and inoculate it into the secondary seed liquid and culture for 20 h as the fermentation seed liquid.

[0103] Using the crushed corn-soybean meal-wheat bran mixture as the fermentation base material, the fermentation group was inoculated with 2% (based on the solid fermentation base material) of the fermentation seed liquid of Lactobacillus ginkgo cqf-43, and then water was added and mixed evenly to make the final water-to-feed ratio 3:1. Seal it, ferment at 30 °C for 24 h. Using the sample before fermentation as the control group, with 3 replicates for each treatment. After fermentation, the feed was dried at 55 °C, and the crude protein (GB / T 6432-2018), acid-soluble protein (NY / T 3801-2020), and soluble sugar (anthrone colorimetric method) in the feed were measured.

[0104] It can be seen from Table 5 that when Lactobacillus ginkgo cqf-43 was used for liquid fermentation of feed, after fermentation, the feed had an acid fragrance, the pH value decreased significantly, and the contents of acid-soluble protein and soluble protein that were easy to absorb in the feed increased significantly, improving the digestion and absorption efficiency of the feed.

[0105] Table 5 Effects of Lactobacillus ginkgo cqf-43 on the nutritional components of feed (%)

[0106]

[0107]

[0108] When the present invention is applied to fermented feed, it is applicable to the breeding of livestock and poultry, including but not limited to: all stages of pig breeding (suckling piglets, weaned piglets, growing pigs, finishing pigs, lactating sows, lactating sows), lambs, calves, etc.

[0109] Example 10 Influence of Strain cqf-43 on the Sedimentation of Feed Raw Materials

[0110] Test method: A mixture of 75% corn, 20% soybean meal, and 5% wheat bran was used as the fermentation substrate. The cqf-43 fermentation group was inoculated with 2% (based on the fermentation substrate) of the cqf-43 bacterial solution. The same treatment without inoculating any bacterial solution was used as the control group. The final water-to-feed ratio was adjusted to 3:1, sealed, and fermented at 37°C for 24 h. After fermentation, it was stirred evenly, allowed to stand, and the feed sedimentation time and the height of the supernatant were observed and recorded.

[0111] Test results: The initial sedimentation time of the control group was 5 - 7 min, the time approaching complete sedimentation was 10 - 12 min, and the supernatant after sedimentation was 15 mm; after the cqf-43 fermentation group was stirred evenly and allowed to stand and sediment for 18 min, the supernatant was 7 mm, and after 40 min, the height of the solid phase from the liquid surface was 8 mm. See Figure 8 .

Claims

1. A Lactobacillus ginkgo cqf-43, with its Latin name being Lactiplantibacillus artgentoratensis cqf-43, was deposited at the Guangdong Provincial Culture Collection of Microorganisms on May 12, 2022, with the deposit registration number GDMCC 62463.

2. Use of Lactiplantibacillus ginkgo cqf-43 as claimed in claim 1 as a fermentation inoculant in fermentation products.

3. An intestinal flora regulator, the active ingredient of which is Lactiplantibacillus ginkgo cqf-43 as claimed in claim 1.

4. An antioxidant, the main component of which is the fermentation broth of Lactiplantibacillus ginkgo cqf-43 as claimed in claim 1.

5. Use of Lactiplantibacillus ginkgo cqf-43 as claimed in claim 1 in feed.

6. A feed, with a pH of 3-4, containing acid-soluble protein > 2.3%, crude protein > 22.1, soluble sugar > 14.7, soluble protein > 16.8; the feed contains Lactiplantibacillus ginkgo cqf-43 as claimed in claim 1.

7. The feed as claimed in claim 6, using a crushed corn-soybean meal-wheat bran mixture as the fermentation substrate, and the inoculation amount of Lactiplantibacillus ginkgo cqf-43 as claimed in claim 1 is 2%.

8. A method for preparing the feed as claimed in claim 6 or 7, mixing the fermentation substrate with Lactiplantibacillus ginkgo cqf-43 as claimed in claim 1, adding water and mixing evenly, with a final water-to-feed ratio of 3:1, sealing and fermenting at 30 °C for 24 h.

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