Microorganism, microbial agent, food, preparation method of food and method for inhibiting growth of pathogenic bacteria in vitro

Abstract

The invention discloses a microorganism, a microbial agent, food and a preparation method of the food, and relates to the field of microorganisms. The microorganism is plant lactobacillus, and the preservation number of the microorganism is CGMCC (China General Microbiological Culture Collection Center) No.30791. The new strain of the plant lactobacillus obtained through screening is excellent in performance, capable of inhibiting growth of escherichia coli and staphylococcus aureus, high in growth speed, high in acid resistance and salt resistance and high in nitrate / nitrite metabolism capacity; when the new strain is used for developing salt-reduced fermented food, lactic acid bacteria are rich in content, nutrition and health are achieved, and the flavor is unique; a food fermentation process developed by utilizing the new strain disclosed by the invention is good in process adaptability, high in fermentation efficiency, short in production period and high in application value.

Description

Technical Field

[0001] The present invention relates to the field of microorganisms, and in particular to a microorganism, a microbial agent, a food and a method for preparing the food. Background Art

[0002] Salt is an essential ingredient in the processing of fermented peppers. It can reduce the water activity of peppers, inhibit the growth of spoilage bacteria, extend the shelf life of peppers, and improve the flavor of peppers. Traditional fermented peppers usually add 15-25% salt and rely on microorganisms attached to the surface of food raw materials for fermentation.

[0003] As the world advocates a low-sodium diet, reduced-salt fermented peppers are gaining more and more attention. Reduced-salt fermented peppers usually add 5 to 12% salt, but during the fermentation process, most lactic acid bacteria still cannot avoid the reduction in viable counts caused by salt stress. Therefore, under natural fermentation conditions, microbial growth is slow and the fermented food production cycle is long, making it difficult to meet the production scale of reduced-salt fermented food preparation.

[0004] Therefore, it is still necessary to screen lactic acid bacteria with good salt and acid resistance and good fermentation performance to meet the development of salt-reduced fermented foods and their fermentation processes. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art to a certain extent. To this end, the present invention provides a microorganism, Lactobacillus plantarum, a microbial agent, a food or feed, a method for preparing a food, and a method for inhibiting pathogenic bacteria in vitro. The new strain of Lactobacillus plantarum screened by the present invention has superior performance, can inhibit the growth of Escherichia coli and Staphylococcus aureus, has a fast growth rate, strong acid and salt resistance, and strong ability to metabolize nitrate / nitrite; the new strain is used to develop salt-reduced fermented food, which is rich in lactic acid bacteria, nutritious and healthy, and has a unique flavor; the food fermentation process developed using the new strain of the present invention has good process adaptability, high fermentation efficiency, short production cycle, and high application value.

[0006] Therefore, in a first aspect of the present invention, the present invention proposes a microorganism. According to an embodiment of the present invention, the microorganism is Lactiplantibacillus plantarum, which was deposited in the General Microbiological Center of China Microorganism Culture Collection Administration on May 27, 2024, with a deposit number of CGMCC No.30791.

[0007] Collection information:

[0008] Strain name: Lactiplantibacillus plantarum FVPHBD2216

[0009] Date of deposit: May 27, 2024

[0010] Depository: China National Microbiological Culture Collection Administration General Microbiology Center

[0011] Deposit number: CGMCC No.30791

[0012] Storage address: No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, Postal Code: 100101

[0013] The new strain of Lactobacillus plantarum screened by the invention has superior performance, can inhibit the growth of Escherichia coli and Staphylococcus aureus, has fast growth speed, strong acid and salt resistance, and strong nitrate / nitrite metabolism ability; the salt-reduced fermented food developed by using the new strain has rich lactic acid bacteria content, healthy nutrition and unique flavor; the food fermentation process developed by using the new strain has good process adaptability, high fermentation efficiency, short production cycle and high application value.

[0014] In a second aspect of the present invention, the present invention provides a microbial agent. According to an embodiment of the present invention, the microbial agent includes the aforementioned microorganisms. The microbial agent of the present invention can be used to prepare fermented food, and the acid produced after activation can also be used to adjust the sour taste of food, and can also be used to adjust the lactic acid bacteria content in food.

[0015] In a third aspect of the present invention, the present invention provides a food or feed. According to an embodiment of the present invention, the food or feed includes at least one of the aforementioned microorganisms or the aforementioned microbial agents. The food of the present invention has low salt content, rich yeast content, healthy nutrition, and unique flavor; the feed of the present invention has low salt content, rich yeast content, and high nutritional value.

[0016] In the fourth aspect of the present invention, the present invention proposes the use of the aforementioned microorganisms or the aforementioned microbial agents in the preparation of food or feed.

[0017] In a fifth aspect of the present invention, the present invention provides a method for preparing food. According to an embodiment of the present invention, the method comprises: fermenting the aforementioned microorganisms, one or more of the aforementioned microbial agents and food raw materials to be fermented to obtain the food. The method according to the embodiment of the present invention has high fermentation efficiency, short production cycle and high application value.

[0018] In the sixth aspect of the present invention, the present invention proposes a method for inhibiting the growth of pathogens in vitro. According to an embodiment of the present invention, it includes: co-culturing at least one of the aforementioned microorganisms and the aforementioned microbial agents with a sample containing pathogens; the pathogens are selected from at least one of Staphylococcus aureus and Escherichia coli. According to the method of the embodiment of the present invention, Lactobacillus plantarum FVPHBD2216 has an antibacterial effect, can effectively inhibit the growth of Staphylococcus aureus and Escherichia coli, and can be used to inhibit the growth of pathogens in vitro.

[0019] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0021] Figure 1 This is a diagram showing the morphological identification results of Lactiplantibacillus plantarum FVPHBD2216 in Example 2 of the present invention;

[0022] Figure 2 It is a growth curve diagram of Lactiplantibacillus plantarum FVPHBD2216 in Example 3 of the present invention;

[0023] Figure 3 The absorbance values ​​(OD) of Lactiplantibacillus plantarum FVPHBD2216 before and after culture in different pH medium in Example 3 of the present invention are 600 ) Investigation result diagram;

[0024] Figure 4 This is a graph showing the results of investigating the number of viable bacteria of Lactiplantibacillus plantarum FVPHBD2216 in culture media with different pH values ​​in Example 3 of the present invention;

[0025] Figure 5 The absorbance values ​​(OD) before and after culture of Lactiplantibacillus plantarum FVPHBD2216 in Example 3 of the present invention in a medium containing different salt concentrations are shown in Table 1. 600 ) Investigation result diagram;

[0026] Figure 6 This is a graph showing the results of investigating the number of viable bacteria of Lactiplantibacillus plantarum FVPHBD2216 in culture media containing different salt concentrations in Example 3 of the present invention;

[0027] Figure 7 This is a graph showing the results of investigating the number of live bacteria of Lactiplantibacillus plantarum FVPHBD2216 during the fermentation of fermented vegetables in Example 4 of the present invention;

[0028] Figure 8 This is a graph showing the results of investigating the acid production of Lactobacillus plantarum FVPHBD2216 in Example 5 of the present invention;

[0029] Fig. 9 This is a graph showing the results of the investigation of the inhibition of the growth of Escherichia coli by Lactobacillus plantarum FVPHBD2216 in Example 6 of the present invention;

[0030] Fig.10 This is a graph showing the results of the investigation of the growth inhibition of Staphylococcus aureus by Lactiplantibacillus plantarum FVPHBD2216 in Example 6 of the present invention;

[0031] Fig.11 This is a graph showing the results of investigating the ability of Lactiplantibacillus plantarum FVPHBD2216 to metabolize nitrite in Example 7 of the present invention.

[0032] Fig.12 This is a graph showing the results of investigating the ability of Lactiplantibacillus plantarum FVPHBD2216 to metabolize nitrate in Example 7 of the present invention. DETAILED DESCRIPTION

[0033] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be understood as limiting the present invention.

[0034] In this document, the terms “include” or “comprising” are open expressions, that is, including the contents specified in the present invention but not excluding other contents.

[0035] In this article, the term "MRS medium" refers to a lactic acid bacteria culture medium, which can be divided into two categories: MRS solid culture medium and MRS liquid culture medium according to the content of the coagulant (usually agarose).

[0036] In this article, the term "Lactobacillus plantarum" is a lactic acid bacterium belonging to the genus Lactiplantibacillus, class Bacilli, order Lactobacillales, family Lactobacillaceae, phylum Firmicutes, Gram-positive, with round, smooth, milky white or milky yellow colonies, and can ferment sugars to produce lactic acid.

[0037] The present invention provides a microorganism, a microbial agent, a food or feed, a method for preparing a food, and a method for inhibiting pathogenic bacteria in vitro, which will be described in detail below.

[0038] microorganism

[0039] The present invention proposes a microorganism. According to an embodiment of the present invention, the microorganism is Lactiplantibacillus plantarum, named FVPHBD2216, and deposited in the General Microbiological Center of China Microbiological Culture Collection Committee on May 27, 2024, with a deposit address of No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, Postal Code: 100101, and a deposit number of CGMCC No. 30791.

[0040] According to an embodiment of the present invention, the 16s rDNA sequencing result of the microorganism is shown as SEQ ID NO:1.

[0041] The new strain of Lactobacillus plantarum screened by the invention has superior performance, can inhibit the growth of Escherichia coli and Staphylococcus aureus, has fast growth speed, strong acid and salt resistance, and strong nitrate / nitrite metabolism ability; the salt-reduced fermented food developed by using the new strain has rich lactic acid bacteria content, healthy nutrition and unique flavor; the food fermentation process developed by using the new strain has good process adaptability, high fermentation efficiency, short production cycle and high application value.

[0042] Herein, the terms "Lactiplantibacillus plantarum FVPHBD2216" and "Lactobacillus plantarum FVPHBD2216" are synonymous.

[0043] Microbial Agents

[0044] The present invention provides a microbial agent. According to an embodiment of the present invention, the microbial agent includes at least one of the aforementioned microorganisms and the aforementioned fermentation products. The microbial agent of the present invention can be used to prepare fermented food, and the acid produced after activation can also be used to adjust the sour taste of food, and can also be used to adjust the lactic acid bacteria content in food.

[0045] It should be noted that the microbial agent of the present invention may be a liquid microbial agent, including but not limited to fermentation products, etc.; it may also be a solid microbial agent, including but not limited to freeze-dried powder, etc.

[0046] In some specific embodiments, the microbial agent is a liquid microbial agent, and the concentration of the microorganism is 1×10 9 ~1×10 12 CFU / mL.

[0047] For example, the concentration of microorganisms in the aforementioned liquid microbial inoculant may be: 1×10 9 CFU / mL, 5×10 9 CFU / mL, 1×10 10 CFU / mL, 5×10 10 CFU / mL, 1×10 11 CFU / mL, 5×10 11 CFU / mL, 1×10 12 CFU / mL.

[0048] It should be noted that, in the microbial agent of the present invention, Lactobacillus plantarum FVPHBD2216 may exist in the form of living cells and / or non-living cells.

[0049] As used herein, "living cells" refer to cells that have the ability to metabolize, reproduce or replicate.

[0050] Exemplarily, the living cells may be immobilized cells. Herein, "immobilized cells" refer to living cells that are fixed on a carrier and can carry out life activities such as growth, development, reproduction, inheritance and metabolism within a certain spatial range.

[0051] In this article, "non-living cells" refer to cells that do not have the ability to metabolize, reproduce and replicate, including but not limited to dry bacteria. Exemplarily, the microbial agent is a freeze-dried powder.

[0052] In some specific embodiments, the Lactobacillus plantarum FVPHBD2216 exists in the form of living cells, dried bacteria, immobilized cells or any other forms.

[0053] In some specific embodiments, the dry bacteria are obtained by freeze-drying the Lactobacillus plantarum FVPHBD2216.

[0054] In some specific embodiments, the microbial agent may also contain food-acceptable strains.

[0055] As used herein, "acceptable in food" refers to substances or compositions that can be consumed by humans, which may be adjusted according to the food requirements of different countries.

[0056] Those skilled in the art will appreciate that the features and advantages described above for microorganisms are also applicable to the microbial agent and will not be described in detail here.

[0057] Food or feed

[0058] The present invention provides a food or feed. According to an embodiment of the present invention, the food or feed comprises at least one of the aforementioned microorganisms or the aforementioned microbial agents. The food or feed of the present invention has low salt content, rich yeast content, is nutritious and healthy, and has a unique flavor.

[0059] According to an embodiment of the present invention, the invention further comprises an auxiliary material or a carrier acceptable to food or feed.

[0060] In some specific embodiments, the aforementioned microorganisms or the aforementioned microbial agents are added or inoculated into food, or added into feed, thereby further obtaining food or feed with low salt content, rich yeast content, healthy nutrition, and unique flavor.

[0061] Exemplarily, the food includes but is not limited to: probiotic tablets, fermented dairy products (such as probiotic yogurt), probiotic solid beverages, probiotic milk powder, probiotic cheese, probiotic soy products, probiotic candies, probiotic fermented vegetables, etc.

[0062] Exemplarily, the feed includes but is not limited to: probiotic fermented feed.

[0063] It should be noted that the characteristics and advantages described above for microorganisms are also applicable to the food or feed and will not be repeated here.

[0064] use

[0065] The present invention also proposes the use of the aforementioned microorganism or the aforementioned microbial agent in preparing food or feed.

[0066] It should be noted that the characteristics and advantages described above for microorganisms are also applicable to this use and will not be repeated here.

[0067] method

[0068] The present invention provides a method for preparing food. According to an embodiment of the present invention, the method comprises: fermenting the aforementioned microorganisms, one or more of the aforementioned microbial agents and a food raw material to be fermented to obtain the food.

[0069] According to an embodiment of the present invention, the food raw materials include but are not limited to: peppers, cabbages, cucumbers, and radishes.

[0070] The present invention also provides a method for inhibiting the growth of pathogenic bacteria in vitro. According to an embodiment of the present invention, the method comprises: co-culturing at least one of the aforementioned microorganisms and the aforementioned microbial agent with a sample containing pathogenic bacteria.

[0071] According to an embodiment of the present invention, the pathogenic bacteria is selected from at least one of Staphylococcus aureus and Escherichia coli.

[0072] It should be noted that the characteristics and advantages described above for microorganisms are also applicable to this method and will not be repeated here.

[0073] The scheme of the present invention will be explained below in conjunction with the embodiments. It will be appreciated by those skilled in the art that the following embodiments are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. Where specific techniques or conditions are not indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used are not indicated by the manufacturer and are all conventional products that can be obtained commercially.

[0074] Example 1: Obtaining Lactobacillus plantarum FVPHBD2216

[0075] The plant lactobacillus FVPHBD2216 of the invention is separated and obtained from Hebei fermented chili sauce.

[0076] The process of strain collection and isolation: Take naturally fermented chopped pepper and add it to sterilized physiological saline. After mixing, dilute and spread it on MRS solid culture medium plates. Incubate it at 37°C, pH 6.2±0.2 for 24-48 hours. Pick out single colonies of different sizes and shapes and streak them on fresh MRS solid culture medium plates. Incubate them at 37°C for 24-48 hours. Repeat the streak purification culture several times until the colonies in the plates are consistent in morphology. Identify them after no other bacteria are found under microscopic examination.

[0077] Strain preservation: Mix the bacterial solution with sterile 50% glycerol in a freezing tube at a ratio of 1:1 and store at -80℃.

[0078] Example 2: Identification of Lactobacillus plantarum FVPHBD2216

[0079] The culture separated and purified in Example 1 was further confirmed to be a pure culture by streaking and smear microscopy, and then the strain morphology and physiological and biochemical identification, 16S rDNA gene PCR amplification and sequencing analysis were performed.

[0080] 1. Morphological and physiological and biochemical identification

[0081] With reference to the Manual of Identification of Common Bacterial Systems, FVPHBD2216 was identified by its morphological characteristics, physiological and biochemical properties.

[0082] The identification results showed that the colony morphology on MRS agar medium was round, medium-sized, convex, slightly white, moist, with neat edges, a diameter of 3mm±1mm, and a yellow back ( Figure 1 ). Gram-positive. Final pH in MRS liquid medium is 3.5.

[0083] 2. PCR amplification and sequencing analysis of 16S rDNA gene

[0084] The 16S rDNA sequence of Lactobacillus plantarum FVPHBD2216 was identified. PCR amplification conditions: 95°C pre-denaturation for 10 min, followed by 30 cycles: 94°C denaturation for 30 s, 56°C annealing for 30 s, 72°C extension for 1.5 min (1 kb / min), 72°C post-extension for 5 min; 4°C storage. The obtained PCR product was detected by 1% agarose gel electrophoresis, and the PCR reaction system is shown in Table 1.

[0085] Table 1 PCR reaction system

[0086] System composition Volume (μL) Primer 27F (10 μmol / L) 2 Primer 1492R (10 μmol / L) 2 2×Gold Star Best Mixed 25 DNA template 2 <![CDATA[ddH2O]]> 19 Total volume 50

[0087] The strains were sent to Shanghai Sangon Biotech Co., Ltd. for 16S rDNA sequence detection. The sequences were compared in GenBank, and a phylogenetic tree was constructed between the strains tested and other strains in the genus using MEGA11.0.13.

[0088] The results showed that the isolated strain FVPHBD2216 was in the same branch as other strains of Lactobacillus plantarum, and its 16S rDNA sequence homology with the strain Lactiplantibacillus plantarum was 99%. Combined with physiological and biochemical identification, FVPHBD2216 was further confirmed to be Lactobacillus plantarum.

[0089] The final identification confirmed that the isolated strain was a strain of Lactobacillus plantarum, named Lactobacillus plantarum FVPHBD2216, which was deposited in the "General Microbiology Center of China Microbiological Culture Collection Administration" on May 27, 2024, with the deposit number CGMCC No.30791.

[0090] The 16S rDNA sequencing result of Lactobacillus plantarum FVPHBD2216 is shown in SEQ ID NO:1.

[0091] TATACTGCAGTCGACGAACTCTGGTATTGATTGGTGCTTGCATCATGATTTACATTTGA

[0092] GTGAGTGGCGAACTGGTGAGTAACACGTGGGAAACCTGCCCAGAAGCGGGGGATAA

[0093] CACCTGGAAACAGATGCTAATACCGCATAACAACTTGGACCGCATGGTCCGAGNTTGA

[0094] AAGATGGCTTCGGCTATCACTTTTGGATGGTCCCGCGGCGTATTAGCTAGATGGTGGG

[0095] GTAACGGCTCACCATGGCAATGATACGTAGCCGACCTGAGAGGGTAATCGGCCACATT

[0096] GGGACTGAGACACGGCCCAAACTCCTACGGGAGGCAGCAGTAGGGAATCTTCCACAA

[0097] TGGACGAAAGTCTGATGGAGCAACGCCGCGTGAGTGAAGAAGGGTTTCGGCTCGTAA

[0098] AACTCTGTTGTTAAAGAAGAACATATCTGAGAGTAACTGTTCAGGTATTGACGGTATTT

[0099] AACCAGAAAGCCACGGCTAACTACGTGCCAGCAGCCGCGGTAATACGTAGGTGGCAA

[0100] GCGTTGTCCGGATTTATTGGGCGTAAAGCGAGCGCAGGCGGTTTTTAAGTCTGATGT

[0101] GAAAGCCTTCGGCTCAACCGAAGAAGTGCATCGGAAACTGGGAAACTTGAGTGCAG

[0102] AAGAGGACAGTGGAACTCCATGTGTAGCGGTGAAATGCGTAGATATATGGAAGAACA

[0103] CCAGTGGCGAAGGCGGCTGTCTGGTCTGTAACTGACGCTGAGGCTCGAAAGTATGGG

[0104] TAGCAAACAGGATTAGATACCCTGGTAGTCCATACCGTAAACGATGAATGCTAAGTGT

[0105] TGGAGGGTTTCCGCCCTTCAGTGCTGCAGCTAACGCATTAAGCATTCCGCCTGGGGAG

[0106] TACGGCCGCAAGGCTGAAACTCAAAGGAATTGACGGGGGCCCGCACAAGCGGTGGA

[0107] GCATGTGGTTTAATTCGAAGCTACGCGAAGAACCTTACCAGGTCTTGACATACTATGC

[0108] AAATCTAAGAGATTAGACGTTCCCTTCGGGGACATGGATACAGGTGGTGCATGGTTGT

[0109] CGTCAGCTCGTGTCGTGAGATGTTGGGTTAAGTCCCCGCAACGAGCGCAACCCTTATTA

[0110] TCAGTTGCCAGCATTAAGTTGGGCACTCTGGTGAGACTGCCGGTGACAAACCGGAGG

[0111] AAGGTGGGGATGACGTCAAATCATCATGCCCCTTATGACCTGGGCTACACACGTGCTA

[0112] CAATGGATGGTACAACGAGTTGCGAACTCGCGAGAGTAAGCTAATCTCTTAAAGCCAT

[0113] TCTCAGTTCGGATTGTAGGCTGCAACTCGCCTACATGAAGTCGGAATCGCTAGTAATC

[0114] GCGGATCAGCATGCCGCGGTGAATACGTTCCCGGGCCTTGTACACACCGCCCGTCACACCATGAGAGTTTGTAACACCCAAAGTCGGTGGGGTAACCTTT (SEQ ID NO: 1).

[0115] Example 3: Investigation of growth characteristics, acid resistance and salt resistance of Lactiplantibacillus plantarum FVPHBD2216

[0116] In this example, the experimental strains were prepared as follows: Lactobacillus plantarum FVPHBD2216 was streaked on an MRS agar plate for 24-48 hours, and a single colony was picked and grown in an MRS liquid medium for 16-20 hours for activation to obtain an activated strain.

[0117] 1. Strain growth characteristics

[0118] The activated strain was inoculated into MRS liquid culture medium at 1% inoculation volume, and cultured at 37°C. The absorbance at 600nm was measured every 1h until the stable period. The growth curve was drawn with the culture time as the horizontal axis and the corresponding absorbance value as the vertical axis ( Figure 2 ).

[0119] The results showed that the first 24 hours of culture was in the growth adaptation period, and Lactobacillus plantarum FVPHBD2216 grew and metabolized rapidly; after 24 hours, it entered the logarithmic growth phase.

[0120] 2. Acid resistance of strains

[0121] The activated strains were inoculated into MRS liquid culture medium with different pH values ​​(pH values ​​of 3, 4, 5, and 6) at a 1% inoculation rate, and cultured at 37°C for 24 h. The absorbance values ​​(OD600) of lactic acid bacteria before and after culture in the culture medium with different pH values ​​were measured. Figure 3 ), and the number of live lactic acid bacteria before and after cultivation was determined by the culturable bacteria determination method ( Figure 4 ).

[0122] The results showed that Lactobacillus plantarum FVPHBD2216 had a high tolerance to acid. When the pH value of the MRS liquid medium was 4-6, the growth condition was good ( Figure 3 , Figure 4 ); when the pH value dropped to 3.5, the survival rate remained high, and the number of viable bacteria was maintained at 10 7 CFU / mL or more ( Figure 4 ).

[0123] 3. Salt tolerance characteristics of strains

[0124] The activated strains were inoculated into MRS liquid culture medium containing different NaCl concentrations (0%, 4%, 8%, 10%, 15%, 20%) at a 1% inoculum, and cultured at 37°C for 24 h. The absorbance values ​​(OD600) of lactic acid bacteria before and after culture in the culture medium with different salt concentrations were measured respectively ( Figure 5 ), and the number of live lactic acid bacteria before and after cultivation was determined by the culturable bacteria determination method ( Figure 6 ).

[0125] The results showed that Lactobacillus plantarum FVPHBD2216 had a high tolerance to NaCl. In a liquid culture medium with a salt concentration of 15%, the strain could still grow; in a liquid culture medium with a salt concentration of 20%, the number of viable bacteria was maintained at 10 4 CFU / mL or more ( Figure 6 ).

[0126] Example 4: Application of Lactiplantibacillus plantarum FVPHBD2216

[0127] In this embodiment, fermented vegetables were prepared using Lactiplantibacillus plantarum FVPHBD2216. The specific method is as follows:

[0128] 1. Preparation of Lactobacillus plantarum FVPHBD2216 starter

[0129] Lactobacillus plantarum FVPHBD2216 was streaked on an MRS agar plate for 24 to 48 hours, and a single colony was picked and grown in an MRS liquid medium for 16 to 20 hours for activation. The activated Lactobacillus plantarum FVPHBD2216 was inoculated into an MRS liquid medium at a 1% inoculum amount for expansion culture for 16 to 20 hours. The bacterial solution was centrifuged, washed with sterile distilled water until no culture medium remained, and resuspended in sterile distilled water. The bacterial cell density was 1×10 10 ~1×10 11 CFU / mL.

[0130] 2. Fermented Vegetable Preparation

[0131] The fermented vegetables are prepared according to the following steps: 50.0 kg of fresh vegetables are selected, washed, drained, and crushed or not, 4.5-7.5 kg of table salt is added and stirred evenly, the amount of salt added is 8%-12% of the total weight of the vegetables, and 1% of the total weight of the vegetables is inoculated with a Lactobacillus plantarum FVPHBD2216 starter culture, and the vegetables are sealed and fermented at room temperature for 30 days to obtain fermented vegetables using Lactobacillus plantarum FVPHBD2216 as a starter culture.

[0132] The results showed that the number of live lactic acid bacteria remained at 10 throughout the fermentation process. 4 CFU / mL or more ( Figure 7 ).

[0133] Exemplarily, vegetables suitable for making fermented vegetables using Lactobacillus plantarum FVPHBD2216 include, but are not limited to: peppers, cabbage, cucumbers, and radishes.

[0134] Example 5: Investigation of acid production characteristics of Lactiplantibacillus plantarum FVPHBD2216

[0135] In this example, the experimental strains were prepared as follows: Lactobacillus plantarum FVPHBD2216 was streaked on an MRS agar plate for 24-48 hours, and a single colony was picked and grown in an MRS liquid medium for 16-20 hours for activation to obtain an activated strain.

[0136] The activated strain was inoculated into MRS liquid culture medium at 1% inoculation volume, and cultured at 37°C. The absorbance at 600nm was measured every 1h until the stable period. The pH of the bacterial solution was measured when the stable period was reached. The results showed that it was basically maintained below 4.0, and the lowest could reach 2.43 ( Figure 8 ).

[0137] Example 6: Investigation of antibacterial properties of Lactiplantibacillus plantarum FVPHBD2216

[0138] 1. Inhibit the growth of E. coli

[0139] Add 200μl distilled water and 10μl fermentation supernatant to the 96-well plate A1-F1 and mix well. Add 100μL LB medium to each of the remaining wells. Aspirate 100μL of the mixture from wells A1-F1 and add it to wells A2-F2 and mix well. Aspirate 100μL from wells A2-F2 and add it to wells A3-F3 and mix well. And so on until wells A10-F10. Take the cultured E. coli and use sterile water to prepare a bacterial suspension with a bacterial concentration equivalent to 0.5 McFarland turbidimetric standard. After diluting it 1:1000 with LB medium, add 100μL of bacterial suspension to wells 1-10 and well 12 in each row and mix well. Place in a 37℃ incubator and incubate for 16-20h. Measure the OD value every 1h until the bacterial density is basically stable and stop measuring.

[0140] The results showed that Lactobacillus plantarum FVPHBD2216 could inhibit the growth of E. coli. Within a certain period of time, the concentration of E. coli in the experimental group was significantly lower than that in the control group ( Fig. 9 ).

[0141] 2. Inhibit the growth of Staphylococcus aureus

[0142] Add 200μl distilled water and 10μl fermentation supernatant to the 96-well plate A1-F1 and mix well. Add 100μL LB medium to each of the remaining wells. Aspirate 100μL of the mixture from wells A1-F1 and add it to wells A2-F2 and mix well. Aspirate 100μL from wells A2-F2 and add it to wells A3-F3 and mix well. And so on until wells A10-F10. Take the cultured Staphylococcus aureus and use sterile water to prepare a bacterial suspension with a bacterial concentration equivalent to 0.5 McFarland turbidity standard. After diluting it 1:1000 with LB medium, add 100μL of bacterial suspension to wells 1-10 and well 12 in each row and mix well. Place in a 37℃ incubator and incubate for 16-20h. Measure the OD value every 1h until the bacterial density is basically stable and stop measuring.

[0143] The results showed that Lactobacillus plantarum FVPHBD2216 could inhibit the growth of Staphylococcus aureus. Within a certain period of time, the concentration of Staphylococcus aureus in the experimental group was significantly lower than that in the control group ( Fig.10 ).

[0144] Example 7: Investigation of the ability of Lactiplantibacillus plantarum FVPHBD2216 to metabolize nitrite and nitrate

[0145] In this embodiment, the experimental strains were prepared as follows: the bacteria stored in a -80°C refrigerator were inoculated into a conical flask containing 100 mL of EM, and the culture was activated by shaking in a constant temperature shaker at 25°C and 160 rpm for 24 hours. After the culture was completed, the bacterial density was adjusted to about 2.0 (i.e., OD600 = 2.0) with sterile water.

[0146] 1. Ability of strains to metabolize nitrite

[0147] Pipette 1mL of bacterial suspension with OD600=2.0 into a new 99mL EM conical flask. The EM without bacterial suspension is the blank control. Shake well and measure the OD value at 600nm. Measure the OD value every 1h until the bacterial density is basically stable and stop measuring. Add 5mL of bacterial suspension with OD600=2.0 into a new 95mL NM conical flask and analyze the changes in nitrite content to determine the ability of the strain to metabolize nitrite. The above experiments all contain blank controls and three parallel groups.

[0148] The results showed that Lactobacillus plantarum FVPHBD2216 had a strong ability to metabolize nitrite. Within a certain period of time, Lactobacillus plantarum FVPHBD2216 continued to metabolize NaNO2. After 24 hours, the amount of NaNO2 metabolized reached more than 12.5 mg / L ( Fig.11 ).

[0149] 2. Ability of strains to metabolize nitrate

[0150] Pipette 1mL of bacterial suspension with OD600=2.0 into a new 99mL EM conical flask. The EM without bacterial suspension is the blank control. Shake well and measure the OD value at 600nm. Measure the OD value every 1h until the bacterial density is basically stable and stop measuring. Add 5mL of bacterial suspension with OD600=2.0 into a new 95mL NM conical flask and analyze the changes in nitrate content to determine the ability of the strain to metabolize nitrate. The above experiments all contain blank controls and three parallel groups.

[0151] The results showed that Lactobacillus plantarum FVPHBD2216 had a strong ability to metabolize nitrate. The NaNO3 metabolism in 24 hours reached more than 57.5 mg / L ( Fig.12 ).

[0152] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0153] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A microorganism, characterized in that The microorganism is Lactiplantibacillus plantarum, which was deposited in the General Microbiology Center of China National Microbiological Culture Collection Administration on May 27, 2024, with the deposit number CGMCC No.30791.

2. A microbial agent, characterized in that: The microorganism according to claim 1.

3. A food or feed, characterized in that It comprises at least one of the microorganisms described in claim 1 or the microbial agent described in claim 2.

4. Use of the microorganism according to claim 1 or the microbial agent according to claim 2 in the preparation of food or feed.

5. A method for preparing food, characterized in that: include: The food is obtained by fermenting one or more of the microorganisms according to claim 1 and the microbial agent according to claim 2 with food raw materials to be fermented.

6. The method according to claim 5, characterized in that The food raw materials include but are not limited to: peppers, cabbages, cucumbers, and radishes.

7. A method for inhibiting the growth of pathogenic bacteria in vitro, characterized in that: include: Co-culturing at least one of the microorganisms of claim 1 and the microbial agent of claim 2 with a sample containing pathogenic bacteria; The pathogenic bacteria is selected from at least one of Staphylococcus aureus and Escherichia coli.

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