Application of bifidobacterium longum in preparation of product for inhibiting growth and proliferation of bacteria

Abstract

The invention belongs to the technical field of microorganisms, and particularly discloses application of bifidobacterium longum CGMCC (China General Microbiological Culture Collection Center) No.20105 in an antibacterial aspect. The invention discloses the bifidobacterium longum subsp. Longum strain CGMCC No.20105 for the first time, and the bifidobacterium longum subsp. Longum strain has the capability of fermenting TPY or MRS to synthesize antibacterial substances, and the fermentation liquor of the bifidobacterium longum subsp. Longum strain has a certain inhibition effect on enteropathogenic bacteria, oral pathogenic bacteria, environmental pathogenic bacteria and antibiotic-tolerant microorganisms. More importantly, the fermentation product does not influence the survival performance of conventional probiotics, which shows that the antibacterial substance synthesized by fermentation of the bifidobacterium longum subsp. Longum strain CGMCC No.20105 has certain safety, specificity and pertinence. Compared with other MRS fermentation strains, the bifidobacterium longum subsp. Longum strain CGMCC No.20105 MRS fermentation liquor has a remarkable antibacterial effect, so that the bifidobacterium longum subsp. Longum strain has a potential application value.

Description

Technical Field

[0001] The present invention relates to the field of microbial technology, and in particular to the use of Bifidobacterium longum in preparing products that inhibit bacterial growth and proliferation. Background Art

[0002] The rampant proliferation of environmental pathogens and spoilage bacteria is one of the main reasons for the frequent occurrence of food safety problems in recent years. These microorganisms directly or indirectly cause various harms to the human body and cause a series of diseases, such as diarrhea caused by Escherichia coli. In addition to the risk of pathogenicity from exogenous ingestion, the inherent enterococci in the human body are also an uncontrollable factor. This conditional pathogen causes bacteremia, respiratory tract and endocarditis in hosts with low immunity. In recent years, with the abuse of antibiotics, the drug resistance of enterococci has gradually increased. In some clinical infection cases, Enterococcus faecium and Enterococcus faecalis are the most common infectious bacteria. Among them, vancomycin-resistant Enterococci (VRE) are particularly common. The widespread spread of this strain around the world has had a great impact on public health and social security. In addition, a large number of pathogenic bacteria are also parasitic in the human oral cavity. Take Nocardia cavitaria as an example. It germinates and grows in a specific oral environment, eventually leading to periodontitis and odontogenic infection.

[0003] At present, the preferred option to inhibit these pathogenic microorganisms is to use chemical preservatives. However, excessive abuse of such preservative technology will lead to a large amount of residues in feed and even food, which will become one of the potential factors threatening human health. Although Nisin, a bacteriocin from Streptococcus lactis, is safe and non-toxic and avoids the residual hazards caused by chemical preservatives, the "lanthionine ring" in its molecule is also harmful to probiotics. Antibiotics are another means of inhibiting bacteria, but long-term use will cause the problem of "antibiotic resistance". Some microorganisms can even survive by withstanding strong antibiotics at the level of vancomycin, such as vancomycin-resistant Enterococcus faecium.

[0004] Bifidobacterium longum is one of the important members of the intestinal flora of the human body. It has many important physiological functions for human health, such as biological barrier, nutrition, anti-tumor effect, immune enhancement, improvement of gastrointestinal function, anti-aging, etc. However, there are very few reports claiming antibacterial function. Therefore, finding a strain of Bifidobacterium longum that has an inhibitory function against pathogenic microorganisms, especially antibiotic-resistant microorganisms, is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0005] In order to solve the above problems, the present application provides the use of Bifidobacterium longum in preparing a product for inhibiting bacterial growth and proliferation, and the preservation number of the Bifidobacterium longum is CGMCC No.20105.

[0006] The deposit information of the strain in this application is as follows:

[0007] Strain name: Bifidobacterium longum subsp. longum

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

[0009] Deposit date: June 18, 2020;

[0010] Name of depository: General Microbiology Center of China Microbiological Culture Collection Administration;

[0011] Abbreviation of depository unit: CGMCC;

[0012] Address of the preservation unit: No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing.

[0013] The beneficial effects brought by the present application include but are not limited to: (1) Bifidobacterium longum fermentation broth 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 inhibition rate of Bifidobacterium longum fermentation broth on intestinal pathogens is greater than 80%. (3) Bifidobacterium longum fermentation broth has no inhibitory effect on probiotics. (4) The antibacterial substances in Bifidobacterium longum fermentation broth are thermally stable. DETAILED DESCRIPTION

[0014] In order to more clearly explain the technical solutions of the embodiments of this specification, the following will briefly introduce the ones needed in the description of the embodiments. Obviously, the following description is only some examples or embodiments of this specification. For ordinary technicians in this field, this specification can also be applied to other similar scenarios based on these without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals represent the same structure or operation.

[0015] As shown in this specification and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "comprise" and "include" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

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

[0017] The present application provides use of Bifidobacterium longum in preparing a product for inhibiting bacterial growth and proliferation, and the preservation number of the Bifidobacterium longum is CGMCC No.20105.

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

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

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

[0021] In some embodiments, more preferably, the intestinal pathogenic bacteria may include any one or more of Staphylococcus aureus, Escherichia coli, Salmonella or Listeria monocytogenes.

[0022] In some embodiments, more preferably, the oral pathogenic bacteria may be Nocardia vacancies.

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

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

[0025] In some embodiments, the Bifidobacterium longum fermentation product has no inhibitory effect on 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 fermentans.

[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 can be Salmonella ATCC 19585.

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

[0031] In some embodiments, the Nocardia cavitas may be Nocardia cavitas ATCC 17041.

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

[0033] In some embodiments, the Pseudomonas fluorescens may be Pseudomonas fluorescens CICC23250.

[0034] In some embodiments, the vancomycin-resistant Enterococcus faecium may be vancomycin-resistant Enterococcus faecium 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 thermophilus 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 fermented Lactobacillus mucilaginosus may be fermented Lactobacillus mucilaginosus CGMCC No.17321.

[0043] In some embodiments, the product contains a fermentation product of Bifidobacterium longum. In some embodiments, preferably, the Bifidobacterium longum can be cultured and fermented using TPY liquid culture medium or MRS liquid culture 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 hours. In some embodiments, the fermentation conditions of Bifidobacterium longum are all anaerobic culture.

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

[0046] In some embodiments, preferably, the product may include any one or more of food, medicine or health care product.

[0047] The experimental methods in the following examples are conventional methods unless otherwise specified. The experimental materials used in the following examples are purchased from conventional biochemical reagent companies unless otherwise specified. The quantitative tests in the following examples are repeated three times, and the results are averaged.

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

[0049] Staphylococcus aureus ATCC6538, purchased from CGMCC, China; Escherichia coli ATCC25922, purchased from ATCC, USA; Salmonella ATCC 19585, purchased from CGMCC, China; Listeria monocytogenes ATCC 19115, purchased from CGMCC, China; Nocardia vacuole ATCC 17041, purchased from ATCC, USA; Bacillus cereus ATCC 11778, purchased from ATCC, USA; Pseudomonas fluorescens CICC23250, purchased from CICC, China; Vancomycin-resistant Enterococcus faecium CICC24261, purchased from CICC, China. Lactobacillus plantarum CGMCC No.0847, provided by Bright Dairy Co., Ltd.; Lactobacillus casei CGMCC No.0828, provided by Bright Dairy 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 Co., Ltd.; Lactobacillus fermentum CGMCC No.17321, provided by Bright Dairy Co., Ltd.; Lactobacillus salivarius CGMCC No.23518, provided by Bright Dairy Co., Ltd.;

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

[0051] 1. Materials and methods

[0052] Preparation of bacterial suspension: Dissolve the lyophilized powder of Bifidobacterium longum BD3150, Salmonella ATCC 19585, Listeria monocytogenes ATCC19115, Nocardia cavitas ATCC 17041, Staphylococcus aureus ATCC6538, vancomycin-resistant Enterococcus faecium CICC24261, and Escherichia coli ATCC25922 in a small amount of sterile distilled water, take a loop with an inoculation loop and streak it on TPY solid medium (purchased from Qingdao High-tech Industrial Park Haibo Biotechnology Co., Ltd., China), incubate anaerobically at 37°C for 48 hours, pick out a single colony with an inoculation loop and put it into 10 mL TPY liquid culture medium (purchased from Qingdao Hi-Tech Industrial Park Haibo Biotechnology Co., Ltd., China) was used. The colonies were evenly dispersed in the liquid culture medium using a vortex oscillator, cultured at 37°C for 24 h, taken out, and inoculated into TPY liquid culture medium with a 2% (v / v) inoculation amount. After culturing again at 37°C for 24 h, the culture was centrifuged at 15,000 rpm for 10 min, the supernatant was discarded, the bacteria were washed twice with sterile distilled water, and then resuspended with sterile water of the original volume of the fermentation liquid to obtain a bacterial suspension of the corresponding microorganism.

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

[0054] Bifidobacterium longum BD3150 and the above pathogenic bacteria were inoculated into TPY liquid culture medium at 2.5% (v / v), cultured overnight at 37°C for 16 hours, and then taken out. The number of pathogenic bacteria was obtained by pouring method counting (aerobic culture) (without BD3150 as control). The calculation formula of the inhibition rate of Bifidobacterium longum BD3150 on intestinal pathogens is as follows:

[0055]

[0056] In the above formula, n 对照 The concentration of pathogenic bacteria (CFU / mL) in the fermentation broth after culturing pathogenic bacteria alone without adding BD3150 to the culture system; n experiment means the concentration of pathogenic bacteria (CFU / mL) in the fermentation broth after culturing BD3150 and pathogenic bacteria together in the culture system.

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

[0058] Table 1 Results of co-culture experiment of Bifidobacterium longum BD3150 and intestinal pathogenic bacteria

[0059] Pathogens <![CDATA[n 实验 (CFU / mL)]]> <![CDATA[n 对照 (CFU / mL)]]> Inhibition rate (%) Staphylococcus aureus <![CDATA[1.7×10 7 ]]> <![CDATA[5×10 8 ]]> 96.6 salmonella <![CDATA[4×10 6 ]]> <![CDATA[4×10 8 ]]> 99 Escherichia coli <![CDATA[9.4×10 7 ]]> <![CDATA[7.1×10 8 ]]> 86.8 Listeria monocytogenes <![CDATA[1.5×10 8 ]]> <![CDATA[7.7×10 8 ]]> 80.5

[0060] It can be seen from the above table that when Bifidobacterium longum BD3150 is co-cultured with intestinal pathogenic bacteria, the proliferation of the above pathogenic bacteria can be significantly inhibited, and the antibacterial effect can reach more than 80%.

[0061] Example 2 - Experiment on the inhibition of intestinal pathogens by TPY fermentation broth of Bifidobacterium longum BD3150

[0062] 1. Materials and methods

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

[0064] Pick one colony of Bifidobacterium longum BD3150 from the fresh TPY solid medium, inoculate it into 10 mL of TPY liquid medium, culture it at 37°C overnight, take it out, centrifuge it at 9000rpm for 15min, take the supernatant, and filter it with a sterile filter membrane to obtain the fermentation broth supernatant sample A. Take out a part of sample A and treat it with boiling water for 5 minutes, cool it and filter it again aseptically to obtain the fermentation broth supernatant sample B. Take the above centrifuged precipitate and wash it repeatedly with sterile water for 3 times, resuspend it with the same volume of sterile water as the original fermentation broth, and obtain the bacterial 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 to 10 6 CFU / mL, take an appropriate amount of bacterial solution and evenly spread it on the TPY plate to obtain the indicator bacteria plate containing different intestinal pathogens.

[0067] 2. Experiment on the inhibition of intestinal pathogens by TPY fermentation broth of Bifidobacterium longum BD3150

[0068] The supernatant samples A and B of the fermentation broth of Bifidobacterium longum BD3150 prepared above and the bacterial sample C were placed on the indicator bacteria plate previously covered with intestinal pathogens (Staphylococcus aureus, Escherichia coli, Salmonella and Listeria monocytogenes) by the Oxford cup method (100uL / cup), cultured 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] Diameter of inhibition zone (mm) Staphylococcus aureus Escherichia coli salmonella Listeria monocytogenes Fermentation broth supernatant sample A 14.8 13.4 13.1 12.1 Fermentation broth supernatant sample B 14.4 12.7 14.6 12.4 Bacteria sample C - - - -

[0071] By comparing samples C and A / B, it can be seen that the inhibitory effect of BD3150 on intestinal pathogens comes from its metabolites and has nothing to do with the nutritional competition of the bacteria themselves; in addition, by comparing samples A and B, it can be seen 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 thermally stable.

[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 inoculum amount of 3% (v / v) into a MRS liquid culture medium containing 0.05% L-cysteine ​​hydrochloride, and anaerobically cultured at 34° C. for 24 h to obtain MRS fermentation broth A.

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

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

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

[0078] The bacterial suspension of Bifidobacterium longum BD3150 prepared in Example 1 was aseptically inoculated into MRS liquid culture medium containing 0.05% L-cysteine ​​hydrochloride at an inoculum amount of 4% (v / v), and anaerobically cultured 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 vacuole ATCC 17041, Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 25922, vancomycin-resistant Enterococcus faecium CICC 24261, Bacillus cereus ATCC 11778 and Pseudomonas fluorescens CICC 23250 were prepared respectively according to the method described in Example 1.

[0081] (b) Preparation of indicator bacteria plates

[0082] Referring to the method described in Example 2, the above pathogenic bacteria suspension was used to prepare indicator bacteria plates containing different pathogenic bacteria.

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

[0084] An Oxford cup was placed on the above pathogenic bacteria indicator bacteria plate, and 100 μL of MRS fermentation broth A, B, C, D and E prepared in the above examples was added to each Oxford cup. The culture was 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 MRS fermentation broth of Bifidobacterium longum BD3150 on pathogenic bacteria

[0086]

[0087] As can be seen from the above table, the diameter of the inhibition zone of the MRS fermentation broth of Bifidobacterium longum BD3150 against intestinal pathogens is ≥14mm, the diameter of the inhibition zone against oral pathogens is ≥13mm, the diameter of the inhibition zone against environmental pathogens is ≥10mm, and the diameter of the inhibition zone against antibiotic-resistant microorganisms is ≥12mm.

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

[0089] 1. Materials and methods

[0090] (a) Preparation of bacterial suspension: 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 fermentans CGMCC 17321 were prepared respectively according to the method described in Example 1.

[0091] (b) Preparation of indicator bacteria plates

[0092] Referring to the method described in Example 2, the above probiotic suspension was used to prepare indicator bacteria plates containing different probiotics.

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

[0094] An Oxford cup was placed on the above-mentioned probiotic indicator bacteria plate, 100 μL of the MRS fermentation liquid A prepared in the above-mentioned example was added to each Oxford cup, and the mixture was cultured at 37° C. for 2 days. The diameter of the inhibition zone was measured. The results are shown in Table 4 below.

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

[0096] Diameter of inhibition zone (mm) MRS fermentation broth A of Bifidobacterium longum BD3150 Lactobacillus plantarum - Lactobacillus casei - Lactobacillus paracasei - Lactobacillus bulgaricus - Streptococcus thermophilus - Lactobacillus rhamnosus - Lactobacillus salivarius - Lactobacillus mucilaginosus fermentation -

[0097] As can be seen from the above table, 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 Effects of MRS Fermentation Broths of Different Strains on Pathogenic Bacteria

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

[0100] 1. Materials and methods

[0101] (a) Preparation of bacterial suspension: 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 vacuole ATCC 17041, Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 25922, vancomycin-resistant Enterococcus faecium CICC 24261, Bacillus cereus ATCC 11778 and Pseudomonas fluorescens CICC 23250) were prepared respectively according to the method described in Example 1.

[0102] (b) Preparation of indicator bacteria plates

[0103] Referring to the method described in Example 2, the above pathogenic bacteria suspension was used to prepare indicator bacteria plates containing different pathogenic bacteria.

[0104] (c) Preparation of MRS fermentation broth of 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 in an MRS liquid culture medium containing 0.05% L-cysteine ​​hydrochloride at an inoculum amount of 3% (v / v), and anaerobically cultured at 34°C for 24 hours to obtain MRS fermentation broths of different strains.

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

[0107] An Oxford cup was placed on the above pathogenic bacteria indicator bacteria plate, 100 μL of the MRS fermentation broth of different strains prepared above was added to each Oxford cup, and the cells were cultured at 37° C. for 2 days. 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 of different strains on pathogenic bacteria

[0109]

[0110] It can be seen from the above table that other MRS fermentation strains do not have the ability to ferment MRS to produce antibacterial substances, while Bifidobacterium longum BD3150 can utilize 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 above detailed disclosure is only for example and does not constitute a limitation of this specification. Although not explicitly stated here, 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, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of this specification.

[0112] At the same time, this specification uses specific words to describe the embodiments of this specification. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of this specification. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures or characteristics in one or more embodiments of this specification can be appropriately combined.

[0113] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate 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 change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of this specification are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0114] Finally, it should be understood that the embodiments described in this specification are only used to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, as an example and not a limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly introduced and described in this specification.

Claims

1. Use of Bifidobacterium longum in preparing a product for inhibiting bacterial growth and proliferation, wherein the preservation number of the Bifidobacterium longum is CGMCC No.20105.

2. The use according to claim 1, characterized in that The bacteria are pathogenic bacteria; And / or, the product contains a fermentation product of Bifidobacterium longum. Preferably, the Bifidobacterium longum is cultured and fermented using TPY liquid culture medium or MRS liquid culture medium.

3. The use according to claim 2, characterized in that The antibacterial substance in the fermentation product of Bifidobacterium longum is thermally stable.

4. The use according to claim 1, characterized in that The bacteria include any one or more of intestinal pathogens, oral pathogens, environmental pathogens or antibiotic-resistant microorganisms.

5. The use according to claim 4, characterized in that The intestinal pathogenic bacteria include any one or more of Staphylococcus aureus, Escherichia coli, Salmonella or Listeria monocytogenes; And / or, the oral pathogen is Nocardia cavitas.

6. The use according to claim 4, characterized in that The environmental pathogenic bacteria are selected from Bacillus cereus or Pseudomonas fluorescens.

7. The use according to claim 4, characterized in that The antibiotic-resistant microorganism is vancomycin-resistant Enterococcus faecium.

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

9. The use according to claim 8, 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 mucosa fermentation.

10. The use according to claim 1, characterized in that The product includes any one or more of food, medicine or health care product.

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