Microorganism, microbial agent, food product, method for preparing food product, and method for producing pectinase

Abstract

The invention discloses a microorganism, a microbial agent, food, a method for preparing the food and a method for producing pectinase, 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.31283. The new strain of the plant lactobacillus obtained through screening has the advantages of being high in growth speed, high in acid production capacity, acid resistance and salt resistance, high in pectinase production capacity, high in nitrite and nitrate metabolism capacity and the like; the new strain is used for developing salt-reduced fermented food, the process adaptability is good, and the prepared fermented food is rich in lactic acid bacteria content, nutritional, healthy and unique in flavor; a food fermentation process developed by utilizing the new strain is 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, a method for preparing the food and a method for producing pectinase. 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] Reduced-salt fermented peppers usually add 5-12% salt, but during the fermentation process, most lactic acid bacteria still cannot avoid the reduction of viable bacteria due to salt stress. Therefore, under natural fermentation conditions, microbial growth is slow and the fermented food production cycle is long, which makes 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 plant lactobacillus FVPHBJ24301 and its application. The present invention also provides a microbial agent, a food or feed, a method for preparing a food, and a method for producing pectinase. The new strain of plant lactobacillus screened by the present invention has the advantages of fast growth rate, strong acid production ability, strong acid and salt resistance, strong pectinase production ability, strong nitrite and nitrate metabolism ability, etc.; the new strain is used to develop salt-reduced fermented food, the process adaptability is good, the fermented food obtained is rich in lactic acid bacteria, nutritious and healthy, and has a unique flavor; the food fermentation process developed using the new strain has high fermentation efficiency, short production cycle, and high application value.

[0006] Therefore, in a first aspect of the present invention, the present invention provides a microorganism. According to an embodiment of the present invention, the microorganism is Lactobacillus plantarum ( Lactiplantibacillus plantarum ), on July 12, 2024, it was deposited in the General Microbiology Center of China Microorganism Culture Collection Administration, with the deposit number CGMCC No.31283.

[0007] Collection information: Strain name: Lactobacillus plantarum Lactiplantibacillus plantarum )FVPHBJ24301 Classification name: Lactobacillus plantarum Lactiplantibacillus plantarum Storage date: July 12, 2024 Depository: China National Microbiological Culture Collection Administration General Microbiology Center Deposit number: CGMCC No.31283 Storage address: No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, Postal Code: 100101 The plant lactobacillus ( Lactiplantibacillus plantarum ) The new strain FVPHBJ24301 has the advantages of fast growth rate, strong acid production ability, strong acid and salt resistance, strong pectinase production ability, and strong ability to metabolize nitrite and nitrate; the use of this new strain to develop salt-reduced fermented foods has good process adaptability, and the fermented foods produced are rich in lactic acid bacteria, nutritious and healthy, and have a unique flavor; the food fermentation process developed using this new strain has high fermentation efficiency, short production cycle, and high application value.

[0008] 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.

[0009] 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 lactic acid bacteria content, healthy nutrition, and unique flavor; the feed of the present invention has low salt content, rich lactic acid bacteria content, and high nutritional value.

[0010] 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.

[0011] In the fifth aspect of the present invention, the present invention proposes the use of the aforementioned microorganism or the aforementioned microbial agent in the production of pectinase.

[0012] In a sixth 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.

[0013] In the seventh aspect of the present invention, the present invention proposes a method for producing pectinase. According to an embodiment of the present invention, the method comprises: subjecting the aforementioned microorganism or the aforementioned microbial agent to bacterial culture to obtain a microbial culture; subjecting the microbial culture to enrichment to obtain bacterial cells; subjecting the bacterial cells to crushing to obtain a cell lysate; subjecting the cell lysate to solid-liquid separation to obtain a supernatant containing the pectinase. The method according to an embodiment of the present invention has a strong ability to produce pectinase, a short production cycle, and a high application value.

[0014] 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

[0015] 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: Figure 1 is the plant lactobacillus ( Lactiplantibacillus plantarum )The morphological identification results of FVPHBJ24301; Figure 2 is the plant lactobacillus ( Lactiplantibacillus plantarum )Growth curve of FVPHBJ24301; Figure 3 is the plant lactobacillus ( Lactiplantibacillus plantarum ) Absorbance values ​​(OD) of FVPHBJ24301 before and after culture in different pH medium 600 ) Survey results diagram; Figure 4 is the plant lactobacillus ( Lactiplantibacillus plantarum )The results of the investigation of the number of viable bacteria of FVPHBJ24301 in culture media with different pH values; Figure 5 is the plant lactobacillus ( Lactiplantibacillus plantarum ) The absorbance values ​​(OD) of FVPHBJ24301 before and after culture in medium containing different salt concentrations 600 ) Survey results diagram; Figure 6 is the plant lactobacillus ( Lactiplantibacillus plantarum )The results of the investigation of the number of viable bacteria of FVPHBJ24301 in culture medium containing different salt concentrations; Figure 7 In the fermentation process of the fermented vegetables in Example 4 of the present invention, Lactobacillus plantarum ( Lactiplantibacillus plantarum )The results of the investigation on the number of viable bacteria of FVPHBJ24301; Figure 8 is the plant lactobacillus ( Lactiplantibacillus plantarum )The investigation result of acid production of FVPHBJ24301; Figure 9 is the plant lactobacillus ( Lactiplantibacillus plantarum )The investigation result of pectinase production of FVPHBJ24301; Figure 10 is the plant lactobacillus ( Lactiplantibacillus plantarum )The results of the investigation on the ability of FVPHBJ24301 to metabolize nitrite; Figure 11 In the fermentation process of the fermented vegetables in Example 6 of the present invention, Lactobacillus plantarum ( Lactiplantibacillus plantarum ) Figure 2. Investigation results of FVPHBJ24301’s ability to metabolize nitrate. DETAILED DESCRIPTION

[0016] 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.

[0017] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0018] 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.

[0019] As used herein, the terms "optionally", "optional" or "optionally" generally mean that the subsequently described event or circumstance may but need not occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.

[0020] 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).

[0021] In this article, the term "Lactobacillus plantarum" refers to a lactic acid bacterium belonging to the phylum Firmicutes ( Bacillota ) Bacillus Bacilli ) Lactobacilliles ( Lactobacillales ) Lactobacillusaceae ( Lactobacillaceae ) Lactobacillus plantarum ( Lactiplantibacillus), Gram-positive, round, smooth, milky white or creamy yellow colonies, able to ferment sugars to produce lactic acid.

[0022] The present invention provides a microorganism, a microbial agent, a food or feed, a method for preparing a food, and a method for producing pectinase, which will be described in detail below.

[0023] microorganism The present invention provides a microorganism. According to an embodiment of the present invention, the microorganism is Lactobacillus plantarum ( Lactiplantibacillus plantarum ), named FVPHBJ24301, and deposited on July 12, 2024 in the General Microbiology Center of China Culture Collection Administration, with the deposit address at No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, Postal Code: 100101, and the deposit number is CGMCC No.31283.

[0024] According to an embodiment of the present invention, the 16s rRNA sequencing result of the microorganism is shown in SEQ ID NO: 1.

[0025] The plant lactobacillus ( Lactiplantibacillus plantarum ) The new strain FVPHBJ24301 has the advantages of fast growth rate, strong acid production ability, strong acid and salt resistance, strong pectinase production ability, and strong ability to metabolize nitrite and nitrate; the use of this new strain to develop salt-reduced fermented foods has good process adaptability, and the fermented foods produced are rich in lactic acid bacteria, nutritious and healthy, and have a unique flavor; the food fermentation process developed using this new strain has high fermentation efficiency, short production cycle, and high application value.

[0026] In this document, the term "Lactobacillus plantarum ( Lactiplantibacillus plantarum )FVPHBJ24301" is synonymous with "Lactobacillus plantarum FVPHBJ24301".

[0027] Microbial Agents 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.

[0028] 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.

[0029] For example, the concentration of microorganisms in the aforementioned liquid microbial inoculant may be: 1×10 9 CFU / mL, 5×10 9CFU / 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.

[0030] 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.

[0031] It should be noted that, in the microbial agent of the present invention, Lactobacillus plantarum may exist in the form of living cells and / or non-living cells.

[0032] As used herein, "living cells" refer to cells that have the ability to metabolize, reproduce or replicate.

[0033] 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.

[0034] 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.

[0035] In some specific embodiments, the Lactobacillus plantarum FVPHBJ24301 exists in the form of living cells, dried bacteria, immobilized cells or any other forms.

[0036] In some specific embodiments, the dry bacteria are obtained by freeze-drying the Lactobacillus plantarum FVPHBJ24301.

[0037] In some specific embodiments, the microbial agent may further contain at least one strain acceptable to food or feed.

[0038] In some specific embodiments, the microbial agent further includes an adjuvant or carrier acceptable in food or an adjuvant or carrier acceptable in animal feed.

[0039] 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.

[0040] In this context, "adjuvant or carrier acceptable in animal feed" refers to a substance or composition that can be consumed by animals, which may be adjusted according to the animal feed requirements of different countries.

[0041] It should be noted that the characteristics and advantages described above for microorganisms are also applicable to the microbial agent and will not be repeated here.

[0042] Food or feed 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 lactic acid bacteria content, healthy nutrition, and unique flavor; the feed of the present invention has low salt content, rich lactic acid bacteria content, and high nutritional value.

[0043] According to an embodiment of the present invention, the invention further comprises an auxiliary material or a carrier acceptable to food or feed.

[0044] 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.

[0045] 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.

[0046] Exemplarily, the feed includes but is not limited to: probiotic fermented feed.

[0047] 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.

[0048] use The present invention also proposes the use of the aforementioned microorganisms or microbial agents in preparing food or feed.

[0049] The present invention also proposes the use of the aforementioned microorganism or the aforementioned microbial agent in producing pectinase.

[0050] 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.

[0051] method 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.

[0052] According to an embodiment of the present invention, the food raw materials include but are not limited to: peppers, cabbages, cucumbers, and radishes.

[0053] The present invention also proposes a method for producing pectinase. According to an embodiment of the present invention, the method comprises: subjecting the aforementioned microorganism or the aforementioned microbial agent to bacterial culture to obtain a microbial culture; subjecting the microbial culture to enrichment to obtain bacterial cells; subjecting the bacterial cells to crushing to obtain a cell lysate; and subjecting the cell lysate to solid-liquid separation to obtain a supernatant containing the pectinase.

[0054] Exemplarily, the enrichment treatment includes but is not limited to streaking Lactobacillus plantarum FVPHBJ24301 on an MRS agar plate for 24 to 48 hours, picking a single colony and growing it in an MRS liquid culture medium for 16 to 20 hours for activation.

[0055] Exemplarily, the conditions for solid-liquid separation include but are not limited to centrifugation at 10000 g and 4° C. for 10 min.

[0056] For example, industrial solid-liquid separation may be performed by methods including but not limited to differential centrifugation, density gradient centrifugation, velocity zonal centrifugation, and industrial bacterial fermentation centrifugation.

[0057] According to an embodiment of the present invention, the disruption process includes: mixing the bacterial cells with the extract and subjecting them to ultrasonic disruption. Based on 1 mL of the extract, the number of cells in the cell lysate is 500×10 4 ~1000×10 4 .

[0058] According to an embodiment of the present invention, the number of cells (10 4 The ratio of the volume of extract (mL) to the volume of extract (mL) was 500:1.

[0059] According to an embodiment of the present invention, the conditions for ultrasonic fragmentation are: power 300w, ultrasound 3 seconds, interval 7 seconds, total time 3min, temperature 4°C.

[0060] According to an embodiment of the present invention, the extract is a liquid reagent for extracting pectinase in a kit.

[0061] 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.

[0062] 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.

[0063] Example 1: Obtaining Lactobacillus plantarum FVPHBJ24301 The plant lactobacillus FVPHBJ24301 of the invention is separated and obtained from Hebei fermented chili sauce.

[0064] The process of strain collection and isolation: Take naturally fermented chopped chili and add it to sterilized saline. After mixing, dilute and spread it on an MRS solid culture medium plate. Incubate it at 37°C for 24-48 h. Pick out single colonies of different sizes and shapes and streak them on a fresh MRS solid culture medium plate. Incubate it at 37°C for 24-48 h. Repeat the streak purification culture several times until the colonies in the plate are consistent in morphology. Identify them after no other bacteria are found under microscopic examination.

[0065] Strain preservation: Mix the bacterial solution with sterile 50% glycerol in a freezing tube at a ratio of 1:1 and store at -80℃.

[0066] Example 2: Identification of Lactobacillus plantarum FVPHBJ24301 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.

[0067] 1 Morphological and physiological and biochemical identification With reference to the Manual of Identification of Common Bacterial Systems, FVPHBJ24301 was identified by its morphological characteristics, physiological and biochemical properties.

[0068] 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 3.5 in MRS liquid medium.

[0069] 2 PCR amplification and sequencing analysis of 16S rDNA gene The 16S rDNA sequence of Lactobacillus plantarum FVPHBJ24301 was identified. PCR amplification conditions: 95℃ pre-denaturation for 10min, followed by 30 cycles: 94℃ denaturation for 30s, 56℃ annealing for 30s, 72℃ extension for 1.5min (1kb / min), 72℃ post-extension for 5min; 4℃ storage. The obtained PCR product was detected by 1% agarose gel electrophoresis, and the PCR reaction system is shown in Table 1.

[0070] Table 1 PCR reaction system

[0071] 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.

[0072] The results showed that the isolated strain FVPHBJ24301 was in the same branch as other strains of Lactobacillus plantarum. Lactiplantibacillus plantarum The 16S rDNA sequence homology of the strain was 99%. Combined with physiological and biochemical identification, FVPHBJ24301 was further confirmed to be Lactobacillus plantarum, and the sequence accession number was CGMCC No.31283.

[0073] The final identification confirmed that the isolated strain was a strain of Lactobacillus plantarum, named Lactobacillus plantarum FVPHBJ24301, which was deposited in the "General Microbiology Center of China Microbiological Culture Collection Administration" on July 12, 2024, with the deposit number CGMCC No.31283.

[0074] The 16S rDNA sequencing result of Lactobacillus plantarum FVPHBJ24301 is shown in SEQ ID NO: 1:

[0075] Example 3: Lactobacillus plantarum ( Lactiplantibacillus plantarum )Investigation on growth characteristics, acid resistance and salt resistance of FVPHBJ24301 In this example, the experimental strains were prepared as follows: Lactobacillus plantarum ( Lactiplantibacillus plantarum ) FVPHBJ24301 was streaked on MRS agar plates for 24-48 h, and a single colony was picked and grown in MRS liquid medium for 16-20 h to activate the strain.

[0076] 1. Strain growth characteristics The activated strain was inoculated into MRS liquid culture medium at 1% inoculation volume and cultured at 37°C. The absorbance at 600 nm was measured every 1 h 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 ).

[0077] The results showed that during the first 24 h of culture, Lactobacillus plantarum ( Lactiplantibacillus plantarum ) FVPHBJ24301 has rapid growth and metabolism and enters the logarithmic growth phase after 24 hours. 2. Acid resistance of the strain 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 ​​(OD 600 )( Figure 3 ), and the number of live lactic acid bacteria before and after cultivation was determined by the culturable bacteria determination method ( Figure 4 ).

[0078] The results showed that Lactobacillus plantarum FVPHBJ24301 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 ).

[0079] 3. Salt tolerance characteristics of strains 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 )( Figure 5 ), and the number of live lactic acid bacteria before and after cultivation was determined by the culturable bacteria determination method ( Figure 6 ).

[0080] The results showed that Lactobacillus plantarum FVPHBJ24301 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 25%, the number of live bacteria was maintained at 10 4 CFU / mL or more ( Figure 6 ).

[0081] Example 4: Lactobacillus plantarum ( Lactiplantibacillus plantarum )Application of FVPHBJ24301 In this example, Lactobacillus plantarum ( Lactiplantibacillus plantarum )FVPHBJ24301 made fermented vegetables. The specific method is as follows: 1. Lactobacillus plantarum FVPHBJ24301 ( Lactiplantibacillus plantarum ) Preparation of starter culture Lactobacillus plantarum FVPHBJ24301 ( Lactiplantibacillus plantarum ) were streaked on MRS agar plates for 24 to 48 h, and single colonies were picked and grown in MRS liquid medium for 16 to 20 h for activation. The activated Lactobacillus plantarum FVPHBJ24301 was inoculated into MRS liquid medium at a 1% inoculum volume for 16 to 20 h. 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.

[0082] 2. Fermented Vegetable Preparation The fermented vegetables were prepared according to the following steps: 50.0 kg of fresh vegetables were vacuum freeze-dried, 4.5-7.5 kg of salt was added and stirred evenly, the amount of salt added was 8%-12% of the total vegetable weight, 1% of the total vegetable weight was inoculated with Lactobacillus plantarum FVPHBJ24301 starter, and the vegetables were sealed and fermented at room temperature for 30 days to obtain fermented vegetables using Lactobacillus plantarum FVPHBJ24301 as the starter.

[0083] 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 ).

[0084] Exemplarily, vegetables suitable for making fermented vegetables using Lactobacillus plantarum FVPHBJ24301 include, but are not limited to: peppers, cabbage, cucumbers, and radishes.

[0085] Example 5: Lactobacillus plantarum ( Lactiplantibacillus plantarum ) Investigation on the acid production and pectinase production characteristics of FVPHBJ24301 In this example, the experimental strains were prepared as follows: Lactobacillus plantarum FVPHBJ24301 was streaked on an MRS agar plate for 24 to 48 hours, and a single colony was picked and grown in an MRS liquid culture medium for 16 to 20 hours for activation to obtain an activated strain.

[0086] 1. Acid production capacity of the strain The activated strain was inoculated into MRS liquid culture medium at 1% inoculation volume and cultured at 37°C. The absorbance at 600 nm was measured every 1 h 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 ).

[0087] 2. Pectinase production characteristics of strains According to the number of cells (10 4 The volume of the extract (mL) was 500-1000:1 (it is recommended to add 1 mL of extract to 5 million cells), and the cells were disrupted by ultrasonic wave in an ice bath (power 300w, ultrasonic wave 3 seconds, interval 7 seconds, total time 3min); then centrifuged at 10000g, 4℃ for 10min, and the supernatant was placed on ice for testing.

[0088] The test was carried out according to the method provided by the kit. The results showed that the pectinase content reached 55 mg / L or more within 24 hours ( Figure 9 ).

[0089] 3. Pectinase activity of strains The pectinase activity was detected by micro-volume method, and the pectinase activity detection kit purchased from Beijing Solebow Technology Co., Ltd. was used for detection. During the microbial culture stage, 1g / L pectin was added to the MRS medium as a fermentation substrate. After culturing at 37°C and 180rpm / min for 24 hours, the fermentation broth was centrifuged at 4°C and 10000rpm / min for 15 minutes, the supernatant was placed on ice for testing, and 1mL of the supernatant was placed in a boiling water bath for 10 minutes. 0.2mL of reagent 1 was added to a 1.5mL centrifuge tube, incubated in a 50°C water bath for 5 minutes, and then 0.04mL of the supernatant after the water bath was added to the centrifuge tube, mixed, reacted in a 50°C water bath for 30 minutes, and immediately boiled in a water bath for 5 minutes. After cooling, centrifuged at 4°C and 10000rpm / min for 15 minutes, took the supernatant, and then added 0.15mL of reagent 2, boiled in a water bath for 5min, and cooled in an ice bath to terminate the reaction. 0.2mL was aspirated in a 96-well plate to measure the absorbance at 540nm. The test results showed that the pectinase activity of the strain was 59.237±0.47U / mL after 24 hours.

[0090] Example 6: Lactobacillus plantarum ( Lactiplantibacillus plantarum )Investigation on the ability of FVPHBJ24301 to metabolize nitrite and nitrate In this example, 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 h. After the culture was completed, the bacterial density was adjusted to about 2.0 (i.e., OD 600 =2.0).

[0091] 1. Ability of strains to metabolize nitrite Pipette 1 mL OD 600 =2.0 bacterial suspension into a new 99 mL EM conical flask. The EM without bacterial suspension is used as a blank control. Shake well and measure its OD value at 600 nm. Measure the OD value every 1 h until the bacterial density is basically stable and stop measuring. 600 =2.0 bacterial suspension was added to a new 95 mL NM conical flask, and the changes in nitrite content were analyzed to determine the ability of the strain to metabolize nitrite. The above experiments all included blank controls and three parallel groups.

[0092] The results showed that Lactobacillus plantarum FVPHBJ24301 had a strong ability to metabolize nitrite. Within a certain period of time, Lactobacillus plantarum FVPHBJ24301 continued to metabolize NaNO2. After 24 hours, the amount of NaNO2 metabolized reached more than 27.5 mg / L ( Figure 10 ).

[0093] 2. Ability of strains to metabolize nitrate Pipette 1 mL OD 600 =2.0 bacterial suspension into a new 99 mL EM conical flask. The EM without bacterial suspension is used as a blank control. Shake well and measure its OD value at 600 nm. Measure the OD value every 1 h until the bacterial density is basically stable and stop measuring. 600 =2.0 bacterial suspension was added to a new 95 mL NM conical flask, and the changes in nitrate content were analyzed to determine the ability of the strain to metabolize nitrate. The above experiments all included blank controls and three parallel groups.

[0094] The results showed that Lactobacillus plantarum FVPHBJ24301 had a strong ability to metabolize nitrate. The NaNO3 metabolism in 24 hours reached more than 50mg / L ( Figure 11 ).

[0095] 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.

[0096] 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 Lactobacillus plantarum ( Lactiplantibacillus plantarum ), on July 12, 2024, it was deposited in the General Microbiology Center of China Microorganism Culture Collection Administration, with the deposit number CGMCC No.31283.

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. Use of the microorganism according to claim 1 or the microbial agent according to claim 2 in producing pectinase.

6. A method for preparing food, characterized in that: include: The food is obtained by fermenting the microorganism according to claim 1 or the microbial agent according to claim 2 with the food raw material to be fermented.

7. A method for producing pectinase, characterized in that: include: The microorganism according to claim 1 or the microbial agent according to claim 2 is subjected to bacterial culture treatment to obtain a microbial culture; The microbial culture is enriched to obtain bacterial cells; After the bacterial cells are crushed, a cell lysate is obtained; The cell lysate is subjected to solid-liquid separation to obtain a supernatant containing the pectinase.

8. The method according to claim 7, characterized in that The disruption process includes: mixing the bacterial cells with the extract and subjecting them to ultrasonic disruption. Based on 1 mL of the extract, the number of cells in the cell lysate is 500×10 4 ~1000×10 4 indivual.

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