Use of bifidobacterium longum in the preparation of a product for inhibiting bacterial growth proliferation

Abstract

The application belongs to the technical field of microorganisms, and particularly discloses application of Bifidobacterium longum subsp. longum CGMCC No. 20105 in bacteriostasis. The application discloses for the first time that the Bifidobacterium longum subsp. longum strain CGMCC No. 20105 has the ability to ferment TPY or MRS to synthesize bacteriostatic substances, and the fermentation liquor has certain inhibitory effect on intestinal pathogenic bacteria, oral pathogenic bacteria, environmental pathogenic bacteria and antibiotic-resistant microorganisms. More importantly, the fermentation product does not affect the survival performance of conventional probiotics, indicating that the bacteriostatic substances synthesized by the Bifidobacterium longum subsp. longum strain CGMCC No. 20105 fermentation have certain safety, specificity and pertinence. Compared with other MRS fermentation strains, the bacteriostatic effect of the MRS fermentation liquor of the Bifidobacterium longum subsp. longum strain CGMCC No. 20105 is remarkable, and therefore has potential application value.

Description

Technical Field

[0001] This specification relates to the field of microbial technology, and in particular to the use of Bifidobacterium longum in the preparation of products that inhibit bacterial growth and proliferation. Background Technology

[0002] The rampant proliferation of environmental pathogens and putrefactive bacteria is one of the main reasons for the frequent food safety problems in recent years. These microorganisms directly or indirectly cause various harms to the human body, triggering a series of diseases, such as diarrhea caused by E. coli. Besides the risk of pathogens from exogenous intake, the endogenous flora of the human body, Enterococcus, is also an uncontrollable factor. This opportunistic pathogen can cause bacteremia, respiratory tract infections, and endocarditis in immunocompromised hosts. In recent years, with the overuse of antibiotics, the drug resistance of Enterococci has been gradually increasing. In some clinical infection cases, Enterococcus faecalis and Enterococcus faecium are the most common infecting bacteria, among which vancomycin-resistant enterococci (VRE) are particularly prevalent. The widespread dissemination of this strain globally has had a significant impact on public health and social safety. Furthermore, a large number of pathogens also reside in the human oral cavity. For example, Nocardia cavitaria germinates and thrives in a specific oral environment, eventually leading to periodontitis and odontogenic infections.

[0003] Currently, the preferred method for suppressing these pathogenic microorganisms is the use of chemical preservatives. However, the overuse of such preservative technologies can lead to large amounts of residues in feed and even food, thus becoming a potential threat to human health. While Nisin, a bacteriocin derived from Lactococcus, is safe and non-toxic, avoiding the residual hazards of chemical preservatives, its "lanothionine ring" is also harmful to probiotics. Antibiotics are another means of inhibiting bacteria, but long-term use can lead to "antibiotic resistance," with some microorganisms even able to survive under strong antibiotics like vancomycin, such as vancomycin-resistant Enterococcus faecium.

[0004] Bifidobacterium longum is an important component of the human gut microbiota, playing a variety of important physiological roles in human health, including biological barrier function, nutritional function, anti-tumor function, immune enhancement, improvement of gastrointestinal function, and anti-aging. However, there are very few reports claiming antibacterial function. Therefore, finding a Bifidobacterium longum strain that can inhibit pathogenic microorganisms, especially antibiotic-resistant microorganisms, is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] To address the aforementioned issues, this application provides the use of Bifidobacterium longum in the preparation of products that inhibit bacterial growth and proliferation, wherein the accession number of Bifidobacterium longum is CGMCC No. 20105.

[0006] The preservation information of the strain applied for is as follows:

[0007] Strain name: Bifidobacterium longum subsp. Bifidobacterium longum subsp. long

[0008] The accession number is: CGMCC No. 20105;

[0009] Date of preservation: June 18, 2020;

[0010] Name of the depository: China General Microbiological Culture Collection Center, China Committee on the Preservation and Management of Microbial Cultures;

[0011] Abbreviation of depositary institution: CGMCC;

[0012] Address of the depository: No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing.

[0013] The beneficial effects of this application include, but are not limited to: (1) the fermentation broth of *Bifidobacterium longum* inhibits the growth and proliferation of intestinal pathogens, oral pathogens, or antibiotic-resistant microorganisms. (2) when *Bifidobacterium longum* is co-cultured with intestinal pathogens, the fermentation broth of *Bifidobacterium longum* has an inhibition rate of >80% against intestinal pathogens. (3) the fermentation broth of *Bifidobacterium longum* has no inhibitory effect on probiotics. (4) the antibacterial substances in the fermentation broth of *Bifidobacterium longum* are thermally stable. Detailed Implementation

[0014] To more clearly illustrate the technical solutions of the embodiments in this specification, a brief introduction will be given below. Obviously, the following description is merely some examples or embodiments of this specification. Those skilled in the art can apply this specification to other similar scenarios without creative effort. Unless obvious from the linguistic context or otherwise specified, the same reference numerals represent the same structure or operation.

[0015] As indicated in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0016] Flowcharts are used in this specification to illustrate the operations performed by the system according to embodiments of this specification. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, the steps can be processed in reverse order or simultaneously. Furthermore, other operations can be added to these processes, or one or more steps can be removed from them.

[0017] This application provides the use of Bifidobacterium longum in the preparation of products that inhibit bacterial growth and proliferation, wherein the accession number of Bifidobacterium longum is CGMCC No. 20105.

[0018] For detailed information on Bifidobacterium longum CGMCC No. 20105 in this application, please refer to patent 202411183325.8.

[0019] In some embodiments, the bacteria may be pathogenic.

[0020] In some embodiments, preferably, the bacteria may include any one or more of enteropathogenic bacteria, oral pathogenic bacteria, environmental pathogenic bacteria, or antibiotic-resistant microorganisms.

[0021] In some embodiments, more preferably, the enteric pathogens may include one or more of Staphylococcus aureus, Escherichia coli, Salmonella, or Listeria monocytogenes.

[0022] In some embodiments, more preferably, the oral pathogen can be Nocardia cavitaria.

[0023] In some embodiments, more preferably, the environmental pathogens may be selected from Bacillus cereus or Pseudomonas fluorescens.

[0024] In some embodiments, more preferably, the antibiotic-resistant microorganism may be vancomycin-resistant Enterococcus faecalis.

[0025] In some embodiments, the fermentation product of Bifidobacterium longum does not inhibit probiotics.

[0026] In some embodiments, preferably, the probiotics include any one or more of Lactobacillus plantarum, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus bulgaricus, Streptococcus thermophilus, Lactobacillus rhamnosus, Lactobacillus salivarius, or Lactobacillus fermentum.

[0027] In some embodiments, the Staphylococcus aureus may be Staphylococcus aureus ATCC6538.

[0028] In some embodiments, the Escherichia coli may be Escherichia coli ATCC25922.

[0029] In some embodiments, the Salmonella may be Salmonella ATCC 19585.

[0030] In some embodiments, the Listeria monocytogenes may be Listeria monocytogenes ATCC 19115.

[0031] In some embodiments, the cavitary Nocardia can be Nocardia cavitary ATCC 17041.

[0032] In some embodiments, the Bacillus cereus may be Bacillus cereus ATCC 11778.

[0033] In some embodiments, the fluorescent Pseudomonas can be Fluorescent Pseudomonas CICC23250.

[0034] In some embodiments, the vancomycin-resistant Enterococcus faecalis may be vancomycin-resistant Enterococcus faecalis CICC24261.

[0035] In some embodiments, the *Lactobacillus plantarum* may be *Lactobacillus plantarum* CGMCC No. 0847.

[0036] In some embodiments, the Lactobacillus casei may be Lactobacillus casei CGMCC No. 0828.

[0037] In some embodiments, the *Lactobacillus paracasei* may be *Lactobacillus paracasei* ATCC 334.

[0038] In some embodiments, the Lactobacillus bulgaricus may be Lactobacillus bulgaricus CGMCC No. 1.16075.

[0039] In some embodiments, the thermophilic streptococcus may be Streptococcus thermophilus CGMCC No. 1.8748.

[0040] In some embodiments, the Lactobacillus rhamnosus may be Lactobacillus rhamnosus CGMCC No. 13310.

[0041] In some embodiments, the Lactobacillus salivarius may be Lactobacillus salivarius CGMCC No. 23518.

[0042] In some embodiments, the fermenting *Lactobacillus mucinus* may be *Lactobacillus mucinus* CGMCC No. 17321.

[0043] In some embodiments, the product contains Bifidobacterium longum fermentation products. Preferably, in some embodiments, the Bifidobacterium longum is cultured and fermented using TPY liquid medium or MRS liquid medium.

[0044] In some embodiments, the fermentation temperature of *Bifidobacterium longum* can be 20–45°C. In some embodiments, the fermentation time of *Bifidobacterium longum* can be 10–40 h. In some embodiments, the fermentation conditions for *Bifidobacterium longum* are all anaerobic culture.

[0045] In some embodiments, the antibacterial substances in the Bifidobacterium longum fermentation broth are thermally stable.

[0046] In some embodiments, preferably, the product can be a pharmaceutical product.

[0047] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the experimental materials used in the following examples were all purchased from conventional biochemical reagent companies. All quantitative experiments in the following examples were performed in triplicate, and the results were averaged.

[0048] The strain information used in this application is as follows:

[0049] Staphylococcus aureus ATCC 6538, purchased from CGMCC, China; Escherichia coli ATCC 25922, purchased from ATCC, USA; Salmonella ATCC 19585, purchased from CGMCC, China; Listeria monocytogenes ATCC 19115, purchased from CGMCC, China; Nocardia cavitaria ATCC 17041, purchased from ATCC, USA; Bacillus cereus ATCC 11778, purchased from ATCC, USA; Pseudomonas fluorescens CICC 23250, purchased from CICC, China; Vancomycin-resistant Enterococcus faecalis CICC 24261, purchased from CICC, China. *Lactobacillus plantarum* CGMCC No. 0847, provided by Bright Dairy & Food Co., Ltd.; *Lactobacillus casei* CGMCC No. 0828, provided by Bright Dairy & Food Co., Ltd.; *Lactobacillus paracasei* ATCC 334, purchased from ATCC, USA; *Lactobacillus bulgaricus* CGMCC No. 1.16075, purchased from CGMCC, China; *Streptococcus thermophilus* CGMCC No. 1.8748, purchased from CGMCC, China; *Lactobacillus rhamnosus* CGMCC No. 13310, provided by Bright Dairy & Food Co., Ltd.; *Lactobacillus fermentum* CGMCC No. 17321, provided by Bright Dairy & Food Co., Ltd.; *Lactobacillus salivarius* CGMCC No. 23518, provided by Bright Dairy & Food Co., Ltd.

[0050] Example 1 - Co-culture experiment of Bifidobacterium longum BD3150 and enteropathogenic bacteria

[0051] 1. Materials and Methods

[0052] Preparation of bacterial suspension: Lyophilized powders of *Bifidobacterium longum* BD3150, *Salmonella* ATCC 19585, *Listeria monocytogenes* ATCC 19115, *Nocardia cavitaria* ATCC 17041, *Staphylococcus aureus* ATCC 6538, vancomycin-resistant *Enterococcus faecalis* CICC 24261, and *Escherichia coli* ATCC 25922 were dissolved in a small amount of sterile distilled water. One loopful was streaked onto TPY solid medium (purchased from Qingdao High-Tech Industrial Park Haibo Biotechnology Co., Ltd., China). The culture was anaerobic at 37°C for 48 h. A single colony was then picked up with an inoculation loop and placed into 10 mL of TPY liquid medium (purchased from Qingdao High-Tech Industrial Park Haibo Biotechnology Co., Ltd., China). The colonies were evenly dispersed in the liquid medium using a vortex mixer and incubated at 37°C for 24 h. The culture was then inoculated into TPY liquid medium at a 2% (v / v) inoculation rate and incubated again at 37°C for 24 h. The culture volume was 15,000... Centrifuge at rpm for 10 minutes, discard the supernatant, wash the bacterial cells twice with sterile distilled water, and then resuspend the bacterial cells in sterile water of the original volume of fermentation broth to obtain the bacterial suspension of the corresponding microorganism.

[0053] 2. Co-culture experiment of Bifidobacterium longum BD3150 and enteropathogenic bacteria

[0054] Bifidobacterium longum BD3150 and the aforementioned pathogenic bacteria were inoculated at 2.5% (v / v) in TPY liquid medium and incubated overnight at 37°C for 16 h. The pathogenic bacteria were then counted using the pour method (aerobic culture) (with the control group without BD3150). The formula for calculating the inhibition rate of Bifidobacterium longum BD3150 against intestinal pathogenic bacteria is as follows:

[0055]

[0056] In the above formula, n 对照 The concentration (CFU / mL) of pathogenic bacteria in the fermentation broth after culturing the pathogenic bacteria alone without the addition of BD3150 in the culture system; n 实验 To ensure that BD3150 and pathogenic bacteria are added to the culture system simultaneously, the concentration of pathogenic bacteria (CFU / mL) in the fermentation broth after co-culturing BD3150 and pathogenic bacteria is determined.

[0057] The results of the co-culture experiment of Bifidobacterium longum BD3150 with enteropathogenic bacteria are shown in Table 1 below.

[0058] Table 1. Results of co-culture experiments of Bifidobacterium longum BD3150 with enteropathogenic bacteria

[0059]

[0060] As shown in the table above, when Bifidobacterium longum BD3150 is co-cultured with intestinal pathogens, it can significantly inhibit the proliferation of the above-mentioned pathogens, and its antibacterial effect can reach more than 80%.

[0061] Example 2 – Inhibition experiment of TPY fermentation broth of Bifidobacterium longum BD3150 on intestinal pathogens

[0062] 1. Materials and Methods

[0063] (a) Preparation of TPY fermentation broth sample of Bifidobacterium longum BD3150

[0064] One colony of *Bifidobacterium longum* BD3150 was picked from fresh TPY solid medium and inoculated into 10 mL of TPY liquid medium. After incubation at 37°C overnight, the colony was centrifuged at 9000 rpm for 15 min. The supernatant was collected and filtered through a sterile membrane to obtain fermentation broth supernatant sample A. A portion of sample A was boiled in water for 5 minutes, cooled, and then filtered aseptically again to obtain fermentation broth supernatant sample B. The precipitate from the centrifugation was washed three times with sterile water and resuspended in the same volume of sterile water as the original fermentation broth to obtain bacterial cell sample C (for control).

[0065] (b) Preparation of indicator bacteria plates

[0066] The intestinal pathogenic bacteria (indicator bacteria) suspension prepared by the method described in Example 1 was diluted with sterile water to a concentration of 10. 6 CFU / mL, take an appropriate amount of bacterial solution and spread it evenly on TPY plates to obtain indicator bacterial plates containing different enteropathogenic bacteria.

[0067] 2. Inhibition experiment of TPY fermentation broth of Bifidobacterium longum BD3150 on intestinal pathogens.

[0068] The supernatant samples A and B of the fermentation broth of Bifidobacterium longum BD3150 prepared above and the bacterial cell sample C were placed on the indicator bacterial plates that had been pre-coated with enteropathogenic bacteria (Staphylococcus aureus, Escherichia coli, Salmonella and Listeria monocytogenes) using the Oxford cup method (100 uL / cup). The plates were incubated at 37°C for 2 days, and the diameter of the inhibition zone was measured. The results are shown in Table 2 below.

[0069] Table 2. Inhibition results of TPY fermentation broth of Bifidobacterium longum BD3150 on intestinal pathogens.

[0070]

[0071] Comparison of samples C and A / B shows that the inhibitory effect of BD3150 on intestinal pathogens comes from its metabolites and is unrelated to nutrient competition among the bacteria themselves. Furthermore, comparison of samples A and B shows that the TPY fermentation broth from Bifidobacterium longum BD3150 has a stable inhibitory effect on intestinal pathogens regardless of whether it is sterilized or not, indicating that the antibacterial substances in the BD3150 TPY fermentation broth are thermostable.

[0072] Example 3 – Inhibitory effect of MRS fermentation broth of Bifidobacterium longum BD3150 on pathogenic bacteria

[0073] 1. Preparation of MRS fermentation broth of Bifidobacterium longum BD3150

[0074] The *Bifidobacterium longum* BD3150 bacterial suspension prepared in Example 1 was aseptically inoculated at an inoculation rate of 3% (v / v) into MRS liquid medium containing 0.05% L-cysteine ​​hydrochloride and cultured anaerobically at 34°C for 24 h to obtain MRS fermentation broth A.

[0075] The *Bifidobacterium longum* BD3150 bacterial suspension prepared in Example 1 was aseptically inoculated at an inoculation amount of 1% (v / v) into MRS liquid medium containing 0.05% L-cysteine ​​hydrochloride and cultured anaerobically at 42°C for 36 h to obtain MRS fermentation broth B.

[0076] The *Bifidobacterium longum* BD3150 bacterial suspension prepared in Example 1 was aseptically inoculated at an inoculation amount of 5% (v / v) into MRS liquid medium containing 0.05% L-cysteine ​​hydrochloride and cultured anaerobically at 26°C for 26 h to obtain MRS fermentation broth C.

[0077] The *Bifidobacterium longum* BD3150 bacterial suspension prepared in Example 1 was aseptically inoculated at an inoculation amount of 2% (v / v) into MRS liquid medium containing 0.05% L-cysteine ​​hydrochloride and cultured anaerobically at 38°C for 18 h to obtain MRS fermentation broth D.

[0078] The *Bifidobacterium longum* BD3150 bacterial suspension prepared in Example 1 was aseptically inoculated at an inoculation amount of 4% (v / v) into MRS liquid medium containing 0.05% L-cysteine ​​hydrochloride and cultured anaerobically at 30°C for 30 h to obtain MRS fermentation broth E.

[0079] 2. Inhibitory effect of MRS fermentation broth of Bifidobacterium longum BD3150 on pathogenic bacteria.

[0080] (a) Preparation of bacterial suspensions: Bacterial suspensions of Salmonella ATCC 19585, Listeria monocytogenes ATCC 19115, Nocardia cavitaria ATCC 17041, Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 25922, vancomycin-resistant Enterococcus faecalis CICC 24261, Bacillus cereus ATCC 11778, and Pseudomonas fluorescens CICC 23250 were prepared according to the method described in Example 1.

[0081] (b) Preparation of indicator bacteria plates

[0082] Referring to the method described in Example 2, indicator plates containing different pathogens were prepared using the above-mentioned pathogenic bacterial suspension.

[0083] (c) Inhibitory effect of MRS fermentation broth of Bifidobacterium longum BD3150 on pathogenic bacteria

[0084] Oxford cups were placed on the above-mentioned pathogenic bacteria indicator plates. 100 μL of the MRS fermentation broth A, B, C, D and E prepared in the above examples were added to each Oxford cup. The cups were incubated at 37°C for 2 days, and the diameter of the inhibition zone was measured. The results are shown in Table 3 below.

[0085] Table 3. Inhibition results of the MRS fermentation broth of Bifidobacterium longum BD3150 against pathogenic bacteria.

[0086]

[0087] As shown in the table above, the MRS fermentation broth of Bifidobacterium longum BD3150 has an inhibition zone diameter of ≥14 mm against enteric pathogens, ≥13 mm against oral pathogens, ≥10 mm against environmental pathogens, and ≥12 mm against antibiotic-resistant microorganisms.

[0088] Example 1 – Inhibitory effect of MRS fermentation broth of Bifidobacterium longum BD3150 on probiotics

[0089] 1. Materials and Methods

[0090] (a) Preparation of bacterial suspensions: Bacterial suspensions of *Lactobacillus plantarum* CGMCC 0847, *Lactobacillus casei* CGMCC 0828, *Lactobacillus paracasei* ATCC 334, *Lactobacillus bulgaricus* CGMCC 1.16075, *Streptococcus thermophilus* CGMCC 1.8748, *Lactobacillus rhamnosus* CGMCC 13310, *Lactobacillus salivarius* CGMCC No. 23518, and *Lactobacillus fermentum* CGMCC 17321 were prepared according to the method described in Example 1.

[0091] (b) Preparation of indicator bacteria plates

[0092] Referring to the method described in Example 2, indicator plates containing different probiotics were prepared using the above-mentioned probiotic suspension.

[0093] 2. Inhibitory effect of MRS fermentation broth of Bifidobacterium longum BD3150 on probiotics

[0094] Oxford cups were placed on the above probiotic indicator bacteria plates, and 100 μL of the MRS fermentation broth A prepared in the above example was added to each Oxford cup. The plates were incubated at 37°C for 2 days, and the diameter of the inhibition zone was measured. The results are shown in Table 4 below.

[0095] Table 4. Inhibition results of the MRS fermentation broth of Bifidobacterium longum BD3150 on probiotics.

[0096]

[0097] As shown in the table above, the MRS fermentation broth of Bifidobacterium longum BD3150 has no inhibitory effect on probiotics including Lactobacillus plantarum, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus bulgaricus, Streptococcus thermophilus, Lactobacillus rhamnosus, Lactobacillus salivarius, and Lactobacillus fermentum.

[0098] Comparative Example 1 – Inhibitory effect of MRS fermentation broth from different strains on pathogenic bacteria

[0099] Referring to the method described in Example 3, the inhibitory effects of MRS fermentation broth prepared from Bifidobacterium longum BD3150, Lactobacillus casei CGMCC 0828, Lactobacillus plantarum CGMCC 0847, and Streptococcus thermophilus CGMCC 1.8748 on different pathogenic bacteria were compared. The specific operation is as follows:

[0100] 1. Materials and Methods

[0101] (a) Preparation of bacterial suspensions: Bacterial suspensions of Bifidobacterium longum BD3150, Lactobacillus casei CGMCC 0828, Lactobacillus plantarum CGMCC 0847, Streptococcus thermophilus CGMCC 1.8748, and pathogenic bacteria (Salmonella ATCC 19585, Listeria monocytogenes ATCC 19115, Nocardia cavitaria ATCC 17041, Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 25922, vancomycin-resistant Enterococcus faecalis CICC 24261, Bacillus cereus ATCC 11778, and Pseudomonas fluorescens CICC 23250) were prepared according to the method described in Example 1.

[0102] (b) Preparation of indicator bacteria plates

[0103] Referring to the method described in Example 2, indicator plates containing different pathogens were prepared using the above-mentioned pathogenic bacterial suspension.

[0104] (c) Preparation of MRS fermentation broth from different strains

[0105] The bacterial suspensions of Bifidobacterium longum BD3150, Lactobacillus casei CGMCC 0828, Lactobacillus plantarum CGMCC0847, and Streptococcus thermophilus CGMCC 1.8748 prepared above were aseptically inoculated at an inoculation amount of 3% (v / v) into MRS liquid medium containing 0.05% L-cysteine ​​hydrochloride and anaerobically cultured at 34°C for 24 h to obtain MRS fermentation broths of different strains.

[0106] 2. Inhibitory effects of MRS fermentation broth from different strains on pathogenic bacteria

[0107] Oxford cups were placed on the above-mentioned pathogenic bacteria indicator bacteria plates, and 100 μL of the prepared MRS fermentation broth of different strains was added to each Oxford cup. The plates were then incubated at 37°C for 2 days, and the diameter of the inhibition zone was measured. The results are shown in Table 5 below.

[0108] Table 5. Inhibition results of MRS fermentation broth from different strains on pathogenic bacteria.

[0109]

[0110] As shown in the table above, other MRS fermentation strains do not have the ability to ferment MRS to produce antibacterial substances, while Bifidobacterium longum BD3150 can use MRS fermentation to synthesize specific products that inhibit various pathogenic bacteria.

[0111] The basic concepts have been described above. Obviously, for those skilled in the art, the detailed disclosure above is merely illustrative and does not constitute a limitation of this specification. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this specification. Such modifications, improvements, and corrections are suggested in this specification and therefore remain within the spirit and scope of the exemplary embodiments described herein.

[0112] Furthermore, this specification uses specific terms to describe embodiments thereof. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of this specification. Therefore, it should be emphasized and noted that references to "an embodiment," "one embodiment," or "an alternative embodiment" in different locations throughout this specification do not necessarily refer to the same embodiment. Moreover, certain features, structures, or characteristics in one or more embodiments of this specification can be appropriately combined.

[0113] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples with the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of range in some embodiments of this specification are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

[0114] Finally, it should be understood that the embodiments described in this specification are merely illustrative of the principles of the embodiments described herein. Other variations may also fall within the scope of this specification. Therefore, alternative configurations of the embodiments described herein are intended to be illustrative rather than limiting, and should be considered consistent with the teachings of this specification. Accordingly, the embodiments described herein are not limited to those explicitly introduced and described herein.

Claims

1. Bifidobacterium longum subsp. ( Bifidobacterium longum subsp. longum Its use in the preparation of products that inhibit bacterial growth and proliferation is characterized by, The preservation number of the *Bifidobacterium longum* subsp. *longum* is CGMCC NO.20105. The product is a pharmaceutical product. The bacteria are any one or more of Staphylococcus aureus, *Escherichia coli*, Salmonella, *Listeria monocytogenes*, *Nocardia cavitaria*, *Bacillus cereus*, *Pseudomonas fluorescens*, or vancomycin-resistant *Enterococcus faecalis*.

2. The use according to claim 1, characterized in that, The product contains fermentation products of Bifidobacterium longum subsp. longum.

3. The use according to claim 1, characterized in that, The *Bifidobacterium longum* subsp. *longum* was cultured and fermented using TPY liquid medium or MRS liquid medium.

4. The use according to claim 2, characterized in that, The antibacterial substances in the fermentation products of *Bifidobacterium longum* subsp. *longum* are thermally stable.

5. The use according to claim 2, characterized in that, The fermentation product of *Bifidobacterium longum* subsp. *longum* has no inhibitory effect on probiotics.

6. The use according to claim 5, characterized in that, The probiotics include any one or more of Lactobacillus plantarum, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus bulgaricus, Streptococcus thermophilus, Lactobacillus rhamnosus, Lactobacillus salivarius, or Lactobacillus fermentum.

Images