Bifidobacterium dentatum capable of utilizing DFA-I and application of bifidobacterium dentatum

Abstract

The invention discloses a Bifidobacterium denaturatum WZL-S1 capable of utilizing DFA-I. The Bifidobacterium denaturatum WZL-S1 is preserved in Guangdong Province Microbial Culture Collection Center on October 14, 2024, the preservation number is GDMCC No: 65257, and the preservation address is Guangdong Province Culture Collection Center on Floor 5, No. 59 Building, No. 100 Courtyard, Xianlie Middle Road, Guangzhou City, China. The strain is used for preparing bifidobacterium dentatum DFA-I fermentation liquor, has good antioxidant, anti-corrosion and oral bacteriostasis effects, and can be used for developing functional products such as antioxidants, green preservatives and oral bacteriostats.

Description

Technical Field

[0001] The invention belongs to the field of microorganisms, and specifically relates to a strain of Bifidobacterium dentate capable of utilizing DFA-Ⅰ and application thereof. Background Art

[0002] Currently, the importance of intestinal microorganisms in human health is receiving more and more attention. Studies have shown that intestinal microorganisms are closely related to the host's nutrient absorption, immune regulation and disease prevention.

[0003] In recent years, probiotics, especially bifidobacteria, have become popular due to their positive effects on intestinal health; as a common probiotic, bifidobacteria have been widely used in various functional foods, health products and pharmaceutical products. Among the many bifidobacteria, Bifidobacterium dentate has attracted much attention due to its strong colonization ability and metabolic activity in the oral and intestinal environment. Bifidobacterium dentate can produce a variety of beneficial metabolites, such as short-chain fatty acids (SCFAs), which play an important role in regulating intestinal pH, inhibiting the growth of harmful bacteria and promoting the health of intestinal epithelial cells.

[0004] Difructose Anhydride I (DFA-I) is a new type of functional oligosaccharide, which is produced by the degradation of inulin (inulin) by inulin fructotransferase I (IFTase I). It has potential benefits such as promoting the growth of probiotics, regulating intestinal flora and enhancing immune function. However, DFA-I is relatively rare in nature, and most intestinal microorganisms have difficulty in directly utilizing DFA-I.

[0005] Existing screening methods mostly focus on the growth ability of probiotics under common carbon sources such as glucose and lactose, while there are fewer studies on the screening of strains that utilize specific functional oligosaccharides such as DFA-I. In addition, there are still many technical bottlenecks in how to apply the screened probiotics that efficiently utilize DFA-I to the development of functional foods and pharmaceutical products. Summary of the invention

[0006] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0007] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0008] Therefore, the object of the present invention is to overcome the deficiencies in the prior art and provide a strain of Bifidobacterium dentium WZL-S1.

[0009] To solve the above technical problems, the present invention provides the following technical solution: Bifidobacterium dentium WZL-S1 was deposited in Guangdong Provincial Microbiological Culture Collection Center on October 14, 2024, with a deposit number of GDMCC No: 65257, and the deposit address is Guangdong Provincial Culture Collection Center, 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, China.

[0010] As a preferred embodiment of the Bifidobacterium dentium WZL-S1 of the present invention, the Bifidobacterium dentium WZL-S1 efficiently utilizes type I difructose anhydride.

[0011] Another object of the present invention is to overcome the deficiencies in the prior art and provide a use of Bifidobacterium dentium WZL-S1 in the preparation of antioxidants, green preservatives, and oral antibacterial agents.

[0012] Another object of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing a DFA-Ⅰ fermentation broth of Bifidobacterium dentium, comprising inoculating a culture of Bifidobacterium dentium WZL-S1 into a DFA-Ⅰ fermentation liquid medium and fermenting under anaerobic conditions to obtain the DFA-Ⅰ fermentation broth of Bifidobacterium dentium.

[0013] As a preferred embodiment of the preparation method of the present invention, the formula of the DFA-Ⅰ fermentation liquid medium is:

[0014] Tryptone 10.00 g / L, yeast extract 5.00 g / L, DFA-Ⅰ 20.00 g / L, triammonium citrate 2.00 g / L, anhydrous sodium acetate 5.00 g / L, magnesium sulfate 0.10 g / L, manganese sulfate 0.05 g / L, dipotassium hydrogen phosphate 2.00 g / L, Tween 80 1.00 mL / L, the pH of the culture medium was adjusted to 6.5.

[0015] As a preferred embodiment of the preparation method of the present invention, the bacterial concentration in the DFA-Ⅰ fermentation liquid culture medium is 1×106 CFU / mL.

[0016] As a preferred embodiment of the preparation method of the present invention, the fermentation condition is anaerobic fermentation at 37° C. for 48 hours.

[0017] Another object of the present invention is to overcome the deficiencies in the prior art and provide a DFA-Ⅰ fermentation broth of Bifidobacterium dentate.

[0018] Another object of the present invention is to overcome the deficiencies in the prior art and provide a use of Bifidobacterium dentate DFA-I fermentation broth in the preparation of food or medicine with antioxidant properties.

[0019] Another object of the present invention is to overcome the deficiencies in the prior art and provide a use of Bifidobacterium dentate DFA-I fermentation broth in the preparation of green preservatives and oral antibacterial agents.

[0020] Beneficial effects of the present invention:

[0021] (1) The present invention provides a method for screening intestinal microorganisms that can utilize DFA-I from human intestinal microorganisms. By isolating and screening the intestinal flora of healthy adults, a strain of Bifidobacterium dentium WZL-S1 that can efficiently utilize DFA-I is obtained. The Bifidobacterium dentium WZL-S1 was deposited in Guangdong Provincial Microbiological Culture Collection Center on October 14, 2024, with a deposit number of GDMCC No: 65257, and the deposit address is Guangdong Provincial Culture Collection Center, 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, China;

[0022] The strain is used to prepare Bifidobacterium dentata DFA-Ⅰ fermentation broth, which has good antioxidant, preservative and oral antibacterial effects and can be used to develop functional products such as antioxidants, green preservatives, oral antibacterial agents, etc.

[0023] (2) The present invention not only expands the application scope of Bifidobacterium dentata, but also provides a new technical approach for developing new functional probiotic products. In particular, for those application scenarios that require regulating the balance of intestinal flora, enhancing immunity or improving oral health, the technology of the present invention has significant application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. 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 creative labor. Among them:

[0025] Figure 1This is a diagram showing the pH changes during the fermentation of Bifidobacterium dentate WZL-S1 with different carbon sources in the embodiment of the present invention.

[0026] Figure 2 OD of Bifidobacterium dentate WZL-S1 in the fermentation process with different carbon sources in the present invention 600 Change graph.

[0027] Figure 3 This is a graph showing the change in carbon source concentration during the fermentation of Bifidobacterium dentate WZL-S1 with different carbon sources in an embodiment of the present invention.

[0028] Figure 4 This is a graph showing changes in acetic acid concentration during fermentation of Bifidobacterium dentate WZL-S1 with different carbon sources in an embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0030] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0031] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0032] The Bifidobacterium dentium WZL-S1 of the present invention was deposited in the Guangdong Provincial Microbiological Culture Collection Center on October 14, 2024, with a deposit number of GDMCC No: 65257, and the deposit address is the Guangdong Provincial Culture Collection Center, 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, China.

[0033] The culture medium involved in the embodiments of the present invention is as follows:

[0034] DFA-Ⅰ screening solid culture medium: tryptone 2.00 g / L, yeast extract 1.00 g / L, DFA-Ⅰ 20.00 g / L, triammonium citrate 2.00 g / L, anhydrous sodium acetate 5.00 g / L, magnesium sulfate 0.10 g / L, manganese sulfate 0.05 g / L, dipotassium hydrogen phosphate 2.00 g / L, Tween 80 1.00 mL / L, agar powder 15.00 g / L, the pH of the culture medium was adjusted to 6.5.

[0035] DFA-Ⅰ screening liquid culture medium: tryptone 2.00 g / L, yeast extract 1.00 g / L, DFA-Ⅰ 20.00 g / L, triammonium citrate 2.00 g / L, anhydrous sodium acetate 5.00 g / L, magnesium sulfate 0.10 g / L, manganese sulfate 0.05 g / L, dipotassium hydrogen phosphate 2.00 g / L, Tween 80 1.00 mL / L, the pH of the culture medium was adjusted to 6.5.

[0036] MRS liquid culture medium: tryptone 10.00 g / L, yeast extract 5.00 g / L, glucose 20.00 g / L, ammonium citrate tribasic 2.00 g / L, anhydrous sodium acetate 5.00 g / L, magnesium sulfate 0.10 g / L, manganese sulfate 0.05 g / L, potassium hydrogen phosphate 2.00 g / L, Tween 80 1.00 mL / L, the pH of the culture medium was adjusted to 6.5.

[0037] DFA-Ⅰ fermentation liquid medium: tryptone 10.00 g / L, yeast extract 5.00 g / L, DFA-Ⅰ 20.00 g / L, triammonium citrate 2.00 g / L, anhydrous sodium acetate 5.00 g / L, magnesium sulfate 0.10 g / L, manganese sulfate 0.05 g / L, dipotassium hydrogen phosphate 2.00 g / L, Tween 80 1.00 mL / L, the pH of the culture medium was adjusted to 6.5.

[0038] Example 1

[0039] DFA-Ⅰ can be used for screening and identification of intestinal microorganisms:

[0040] 1. Collection of stool samples

[0041] Fresh stool samples were obtained from 5 healthy volunteers (aged 20 to 30 years old) who maintained a normal diet, had not used antibiotics for at least 3 months, and had a normal body mass index. The stool was resuspended in sterile saline and filtered through four layers of sterile gauze to obtain a 10% (w / v) fecal suspension.

[0042] (II) DFA-Ⅰ can be used for intestinal microbial screening:

[0043] (1) Dilute 10% (w / v) fecal suspension 5000 times with saline and apply it to DFA-Ⅰ screening solid medium and culture it in an anaerobic workstation for 48 h;

[0044] (2) Pick a single colony and place it in DFA-Ⅰ screening liquid medium and culture it in an anaerobic workstation for 48 h;

[0045] (3) The supernatant of the fermentation broth was taken and the DFA-Ⅰ content was determined by high performance liquid chromatography to determine the human intestinal microorganisms that can efficiently utilize DFA-Ⅰ.

[0046] (4) Extract single bacterial genomic DNA using the EZNAStool DNA kit (Omega Bio-tek);

[0047] (5) 16S rDNA was amplified using universal primers 27F (5′-AGAGTTTGATCCTGGCTCAG-3′) and 1492R (5′-GGTTACCTTGTTACGACTT-3′) for bacterial species identification;

[0048] (6) Prepare 1% agarose gel, mix the PCR product with loading buffer and load it, run at 150 V and 100 mA for 20 min, observe and cut the gel;

[0049] (7) The obtained PCR product was sent to a professional sequencing company for sequencing, and the sequencing result was: CGGACTAGAGCTACCTTAGACGGCTCCATCCCACAAGGGGTTAGGCCACCGGCTTCGGGTGCTGCCCACTTTCATGACTTGACGGGCGGTGTGTACAAGGCCCGGGAACGCATTCACCGCGGCGTTGCTGATCCGCGATTACTAGCGACTCCGCCTTCATGGAGTCGGGTTGCAGACTCCAATCCGAACTGAGACCGGTTTTCAGGGATCCGCTCCATGTCGCCATGTCGCATCCCGCTGTACCGGCCATTGTAGCATGCGTGAAGCCCTGGACGTAAGGGGCATGATGATCTGACGTCATCCCCACCTTCCTCCGAGTTGACCCCGGCGGTCCCCCGTGAGTTCCCACCATGACGTGCTGGCAACACAGGGCGAGGGTTGCGCTCGTTGCGGGACTTAACCCAACATCTCACGACACGAGCTGACGACGACCATGCACCACCTGTGAACCCGCCCCGAAGGGAGGCCATATCTCTACGGCTGTCGGGAACATGTCAAGCCCAGGTAAGGTTCTTCGCGTTGCATCGAATTAATCCGCATGCTCCGCCGCTTGTGCGGGCCCCCGTCAATTTCTTTGAGTTTTAGCCTTGCGGCCGTACTCCCCAGGCGGGATGCTTAACGCGTTAGCTCCGACACGGAACCCGTGGAACGGGCCCCACATCCAGCATCCACCGTTTACGGCGTGGACTACCAGGGTATCTAATCCTGTTCGCTCCCCACGCTTTCGCTCCTCAGCGTCAGTGACGGCCCAGAGACCTGCCTTCGCCATTGGTGTTCTTCCCGATATCTACACATTCCACCGTTACACCGGGAATTCCAGTCTCCCCTACCGCACTCCAGCCCGCCCGTACCCGGCGCAGACCCACCGTTAAGCGATGGGCTTTCAC.

[0050] The sequencing results were searched and compared in the GeneBank database using BLAST, and the results showed that the similarity with Bifidobacterium dentium 2337 was as high as 99.72%.

[0051] The fermentation liquid was Gram-stained and observed under an electron microscope at 100 times magnification to determine that the strain was Gram-positive rod-shaped. The strain was identified as Bifidobacterium dentium by 16S rDNA and colony morphology and named Bifidobacterium dentium WZL-S1.

[0052] Example 2

[0053] Fermentation of Bifidobacterium dentata under different carbon sources:

[0054] The Bifidobacterium dentata obtained in Example 1 was inoculated into MRS liquid medium and DFA-Ⅰ fermentation liquid medium respectively. The initial bacterial liquid concentration of each medium was 1×10 6 CFU / mL;

[0055] Fermentation was carried out under anaerobic conditions at 37°C for 48 hours;

[0056] During the fermentation process, samples were taken every 6 hours to measure the pH value, bacterial growth concentration (OD600), glucose or DFA-Ⅰ concentration, and acetic acid concentration of the fermentation broth.

[0057] pH changes of Bifidobacterium dentate WZL-S1 during fermentation with different carbon sources Figure 1 OD of Bifidobacterium dentate WZL-S1 during fermentation with different carbon sources 600 Changes see Figure 2 , the changes of carbon source concentration during the fermentation of Bifidobacterium dentata WZL-S1 with different carbon sources refer to Figure 3 , the changes of acetic acid concentration of Bifidobacterium dentata WZL-S1 during fermentation with different carbon sources refer to Figure 4 ;

[0058] It can be seen that when compared with the culture medium containing glucose as the only carbon source, the results of the growth curve and the change in carbon source concentration show that Bifidobacterium WZL-S1 can efficiently utilize DFA-Ⅰ for growth, and the fermentation process of DFA-I may be more involved in the metabolic pathway of acetic acid, which is of great significance for the development of functional fermentation products based on DFA-I.

[0059] Example 3

[0060] In vitro antioxidant evaluation of fermented liquid:

[0061] (1) DPPH scavenging ability test

[0062] The total antioxidant capacity (T-AOC) test kit (DPPH method) was used for determination. The fermentation broth of Bifidobacterium dentate and the fermentation broth of Bifidobacterium dentate DFA-Ⅰ were centrifuged at 5000 rpm for 10 min at 4°C, and then the supernatant was taken as the sample to be tested.

[0063] Next, add 50 μL of the extract in the kit to the blank tube, and then add 950 μL of reagent 1 (the main component is 1,1-diphenyl-2-picrylhydrazyl), ensuring thorough mixing.

[0064] Similarly, 50 μL of the sample to be tested was first added to the test tube, followed by 950 μL of reagent 1, and after thorough mixing, the mixture was allowed to stand at room temperature in the dark for 20 minutes. The absorbance at 515 nm was measured using an enzyme marker.

[0065] DPPH clearance calculation formula:

[0066]

[0067] According to the formula, the DPPH radical scavenging rate of the fermentation broth of Bifidobacterium dentate was 69.01%, and the DPPH radical scavenging rate of the fermentation broth of Bifidobacterium dentate DFA-Ⅰ was 74.72%. The results show that the Bifidobacterium dentate has good DPPH radical scavenging ability, and Bifidobacterium dentate DFA-Ⅰ has better DPPH radical scavenging ability.

[0068] (2) Determination of hydroxyl radical scavenging ability

[0069] In a centrifuge tube, add 1 mL of 9 mmol / L FeSO4, 1 mL of the activated bacterial solution, 3 mL of 9 mmol / L salicylic acid-ethanol solution, and 1 mL of 8.8 mmol / L H2O2 solution in sequence.

[0070] The mixed solution was heated in a water bath at 37°C for 15 min, and then the absorbance at a wavelength of 510 nm was measured;

[0071] The sample solution and H2O2 solution were replaced with equal volumes of distilled water, and set as blank group and sample blank group.

[31] . Calculation formula for hydroxyl radical scavenging rate:

[0072]

[0073] According to the formula, the hydroxyl radical scavenging ability of the fermentation broth of Bifidobacterium dentate was 75.26%, and the hydroxyl radical scavenging ability of the fermentation broth of Bifidobacterium dentate DFA-Ⅰ was 78.63%. The results show that the Bifidobacterium dentate has good hydroxyl radical scavenging ability, and Bifidobacterium dentate DFA-Ⅰ has better hydroxyl radical scavenging ability.

[0074] (3) Determination of superoxide anion free radical scavenging ability

[0075] Add 3mL of Tris-HCl with a pH of 8.2 to the centrifuge tube, place the centrifuge tube in a 25℃ water bath for 25min, add 1mL of pyrogallol and 1mL of the activated bacterial solution to the tube in turn, mix well and continue to react in a 25℃ water bath for 10min, measure the absorbance at a wavelength of 320nm, replace the sample solution with an equal volume of physiological saline as the blank group, and replace Tris-HCl and pyrogallol as the sample blank group. The superoxide anion radical scavenging rate calculation formula is:

[0076]

[0077] According to the formula, the superoxide anion radical scavenging ability of the fermentation broth of Bifidobacterium dentate was 48.74%, and the superoxide anion radical scavenging ability of the fermentation broth of Bifidobacterium dentate DFA-Ⅰ was 48.97%. From the results, it can be seen that both the fermentation broth of Bifidobacterium dentate and the fermentation broth of Bifidobacterium dentate DFA-Ⅰ have good superoxide anion radical scavenging ability, and the results are not much different.

[0078] Example 4

[0079] Determination of the antibacterial ability of Diplococcus denticulatus in vitro:

[0080] (1) Preparation of bacterial suspension: Take an appropriate amount of E. coli strain and inoculate it into a pre-prepared sterile LB liquid medium at a 2% inoculation rate. Then, place the medium in a constant temperature shaker at 37°C for 12 hours;

[0081] For further expansion, 4 mL of the culture solution was taken out and added to 200 mL of LB liquid medium to adjust the concentration of the E. coli culture solution to 1×10 8 CFU / mL~5×10 8 CFU / mL, and the OD was measured by microplate reader 600 The pH value is 0.5-0.65, which is used as the experimental bacterial suspension. It should be stored at 1℃-4℃ and used within 4 hours.

[0082] (2) Preparation of test plates: First, the E. coli suspension was diluted with LB solid medium cooled to about 55°C at a ratio of 1:10;

[0083] Specific operations:

[0084] Take 200mL of LB solid culture medium, add 20mL of Escherichia coli suspension into it, and stir thoroughly to mix. Then, pour 20mL of the mixture into a sterile culture dish. Then, gently shake the culture dish clockwise and counterclockwise to ensure that the bacterial suspension can be evenly distributed on the plate. After the culture medium on the plate solidifies, the preparation of the test plate is completed and can be used later.

[0085] (3) Determination of antibacterial activity: Place the Oxford cup gently on the prepared test plate;

[0086] Then, 200 μL of Bifidobacterium dentate fermentation liquid and Bifidobacterium dentate DFA-Ⅰ fermentation liquid were accurately added into the corresponding Oxford cups;

[0087] At the same time, in order to establish a blank control, 200 μL of LB liquid culture medium was also added to the Oxford cup. Five groups were made in parallel, and the plates were placed upright in a 37°C constant temperature incubator for 14 hours and then taken out to measure the diameter of the inhibition zone of the sample to be tested and the blank control group.

[0088] The operations for culturing Staphylococcus aureus, Streptococcus mutans, and Porphyromonas gingivalis are the same as above, wherein the culture medium for culturing Staphylococcus aureus is LB medium, the culture medium for Streptococcus mutans is commercially available BHI medium, and the culture medium for Porphyromonas gingivalis is commercially available Columbia blood plate medium.

[0089] The culture conditions for Staphylococcus aureus were a 37°C constant temperature incubator, and the culture conditions for Streptococcus mutans and Porphyromonas gingivalis were a 37°C anaerobic workstation.

[0090] The antibacterial results are shown in Table 1 below.

[0091] Table 1

[0092]

[0093] The antibacterial effect of DFA-I fermentation broth of Bifidobacterium dentate on all tested strains was better than that of fermentation broth using glucose as carbon source, especially against Porphyromonas gingivalis. These results indicate that DFA-I as a carbon source may induce Bifidobacterium dentate to produce stronger antibacterial substances, suggesting that DFA-I fermentation broth of Bifidobacterium dentate has potential application value in the development of antibacterial agents and oral care products.

[0094] Example 5

[0095] Determination of drug resistance of Bifidobacterium dentata:

[0096] (1) Preparation of drug sensitive paper discs: First, use a hole punch to cut the filter paper into circular discs with a diameter of 6 mm;

[0097] Next, the paper sheets were placed in a clean and dry beaker and then sterilized at 121°C for 20 minutes.

[0098] After sterilization, dry the paper and store it properly for later use. Prepare antibiotic paper with appropriate concentrations. The concentrations are shown in Table 2. Take 10 μL of the drug solution and drop it on the dried paper in the clean bench to make drug-sensitive paper with the specified content. Dry it naturally and set it aside.

[0099] Table 2 Antibiotics and their contents

[0100]

[0101] Take 30 μL of activated bacterial liquid of Bifidobacterium dentata and spread it evenly on the MRS solid plate with a spreading rod. Use tweezers to pick up different antibiotic sensitive paper discs and carefully place them on the surface of the culture medium. Use paper discs containing 10 μL of MRS liquid culture medium as the blank control group. Make 3 parallel groups to ensure that the spacing between the sensitive paper discs is greater than 25 mm, and the center of the sensitive paper disc is greater than 15 mm from the edge of the culture dish. Incubate at a constant temperature of 37°C anaerobic workstation for 18 h, measure and record the diameter of the inhibition zone. The results are shown in Table 3.

[0102] Table 3 Antibiotic resistance results of Bifidobacterium dentata

[0103]

[0104] The drug resistance of Bifidobacterium dentate WZL-S1 was determined, and the results showed that there were significant differences in the sensitivity of this strain to different antibiotics. Bifidobacterium dentate WZL-S1 was highly sensitive to β-lactam antibiotics such as ampicillin and ceftazidime, but showed strong resistance to neomycin. This strain showed diversity in responding to the effects of antibiotics, which provides a basis for its survival and adaptability in an antibiotic environment, and also suggests that its resistance characteristics should be considered when developing probiotic preparations.

[0105] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the present invention.

Claims

1. Bifidobacterium dentium WZL-S1 was deposited in Guangdong Microbiological Culture Collection Center on October 14, 2024, with the deposit number GDMCC No: 65257. The deposit address is Guangdong Microbiological Culture Collection Center, 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, China.

2. The Bifidobacterium dentium WZL-S1 according to claim 1, characterized in that: The Bifidobacterium dentium WZL-S1 efficiently utilizes type I difructose anhydride.

3. Use of Bifidobacterium dentium WZL-S1 as claimed in claim 1 or 2 in the preparation of antioxidants, green preservatives and oral antibacterial agents.

4. A method for preparing a DFA-Ⅰ fermentation broth of Bifidobacterium dentata, characterized in that: The method comprises inoculating the culture of Bifidobacterium dentium WZL-S1 described in claim 1 into a DFA-Ⅰ fermentation liquid medium, and fermenting under anaerobic conditions to obtain the Bifidobacterium dentium DFA-Ⅰ fermentation liquid.

5. The preparation method according to claim 4, characterized in that: The formula of the DFA-Ⅰ fermentation liquid medium is: Tryptone 10.00 g / L, yeast extract 5.00 g / L, DFA-Ⅰ 20.00 g / L, triammonium citrate 2.00 g / L, anhydrous sodium acetate 5.00 g / L, magnesium sulfate 0.10 g / L, manganese sulfate 0.05 g / L, dipotassium hydrogen phosphate 2.00 g / L, Tween 80 1.00 mL / L, the pH of the culture medium was adjusted to 6.

5.

6. The preparation method according to claim 4 or 5, characterized in that: The bacterial concentration in the DFA-Ⅰ fermentation liquid culture medium is 1×106 CFU / mL.

7. The preparation method according to claim 6, characterized in that: The fermentation condition is anaerobic fermentation at 37° C. for 48 hours.

8. The DFA-Ⅰ fermentation liquid of Bifidobacterium dentate obtained by the preparation method according to any one of claims 4 to 7.

9. Use of the DFA-Ⅰ fermentation broth of Bifidobacterium dentate according to claim 8 in the preparation of food or medicine with antioxidant properties.

10. Use of the DFA-Ⅰ fermentation broth of Bifidobacterium dentata according to claim 8 in the preparation of green preservatives and oral antibacterial agents.

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