Lactobacillus pentosus and application thereof

Abstract

The invention discloses a lactobacillus pentosus, which is named as lactobacillus pentosus ZY1, and the preservation number of the lactobacillus pentosus ZY1 is GDMCC (China General Microbiological Culture Collection Center) No.66473. The lactobacillus pentosus ZY1 is named as lactobacillus pentosus ZY1, and the preservation number of the lactobacillus pentosus ZY1 is GDMCC No.66473. The lactobacillus pentosus ZY1 provided by the invention has salt tolerance and high degradation activity on nitrite, can be used for reducing the content of nitrite in fermented products and preparing fermented products such as pickled vegetables, and is particularly suitable for preparing low-nitrite pickled vegetables by fermenting Chinese cabbages.

Description

Technical Field

[0001] The invention belongs to the technical field of microorganisms and mainly relates to a lactobacillus pentosus plantarum and application thereof. Background Art

[0002] Kimchi is a traditional fermented vegetable product in my country. Its production typically utilizes traditional natural fermentation, utilizing naturally occurring lactic acid bacteria to ferment vegetables. However, this traditional natural fermentation process presents challenges such as bacterial contamination and long fermentation cycles. Furthermore, during the initial stages of natural fermentation, the presence of abundant oxygen encourages the proliferation of nitrate-reducing aerobic bacteria, leading to the rapid production and accumulation of nitrite in kimchi. Consequently, traditional fermented kimchi carries the risk of excessive nitrite levels. Using lactic acid bacteria inoculation to ferment kimchi is a safe and effective method for controlling nitrite levels. Precise fermentation through lactic acid bacteria inoculation effectively inhibits the growth of harmful microorganisms, reducing the presence of these bacteria in the kimchi raw materials and, consequently, reducing nitrite production. Furthermore, the appropriate lactic acid bacteria impart a richer organic acid content and enhanced flavor to kimchi, making inoculated fermentation significantly superior to natural fermentation.

[0003] However, since most commercially available strains are derived from dairy products or human feces, they are not well suited to growing in vegetable substrates. Consequently, when commercial lactic acid bacteria are used to ferment kimchi, the resulting kimchi lacks flavor and is difficult to achieve the appropriate acidity. Furthermore, the current application of nitrite-reducing lactic acid bacteria in kimchi production is primarily focused on vegetables like celery and mustard greens; methods for producing low-nitrite kimchi using bok choy as a fermentation raw material have yet to be reported. Summary of the Invention

[0004] The main purpose of the present invention is to provide a plant lactobacillus pentosus ( Lactiplantibacillus pentosus ) ZY1, to solve at least one of the above technical problems.

[0005] According to one aspect of the present invention, a strain of Lactobacillus pentosus is provided.

[0006] The present invention provides a lactobacillus pentosus plant bacillus derived from commercially available Sichuan naturally fermented sour cowpea, which has been identified as lactobacillus pentosus plant bacillus ( Lactiplantibacillus pentosus ), named it Lactobacillus pentosus ZY1, and preserved it in Guangdong Microbial Culture Collection Center, the preservation location is Guangdong Microbial Culture Collection Center, 5th Floor, Building 59, Compound 100 Xianlie Middle Road, Guangzhou, the preservation number is GDMCC No.66473, and the preservation date is June 6, 2025.

[0007] The Lactobacillus pentosus ZY1 provided by the present invention is a lactic acid bacterium that is salt-tolerant and has high nitrite degradation activity. It can be used to reduce the nitrite content in fermented products and to prepare low-nitrite pickles, thereby achieving precise fermentation and nitrite control.

[0008] In some embodiments, the fermentation raw materials for producing kimchi using the Lactobacillus pentosus ZY1 provided by the present invention include but are not limited to Chinese cabbage, cowpea, celery, mustard, Chinese cabbage, cabbage, carrot, white radish, pepper, cucumber, etc.

[0009] According to another aspect of the present invention, a bacterial agent is provided, comprising the Lactobacillus pentosus ZY1 provided by the present invention. The bacterial agent can be used to reduce the nitrite content in fermented products and to prepare low-nitrite kimchi.

[0010] According to another aspect of the present invention, a method for preparing low-nitrite kimchi by fermenting cabbage with the Lactobacillus pentosus ZY1 of the present invention is provided, comprising the following steps: The milk cabbage, the bacterial suspension of Lactobacillus pentosus ZY1, the sodium chloride solution and the seasoning are added into a fermentation device for fermentation to obtain the product.

[0011] In some embodiments, a method for preparing low-nitrite kimchi by fermenting cabbage with Lactobacillus pentosus ZY1 comprises the following steps: A 1-7.5% (w / v) sodium chloride solution is sterilized and inoculated with a 1-5% (v / v) suspension of Lactobacillus pentosus ZY1. Rice vinegar and cooking wine are then added at 0.5-1.5% (v / v) based on the volume of the sodium chloride solution to obtain a fermentation broth. The method comprises adding the milk cabbage into a fermentation device, then adding fermentation liquid, sealing the device and performing fermentation to obtain the product.

[0012] In some embodiments, the concentration of the sodium chloride solution may be 5% (w / v).

[0013] In some embodiments, the sterilization method may be sterilization at 121° C. for 20 min.

[0014] In some embodiments, the concentration of the Lactobacillus pentosus ZY1 suspension can be 1×10 8 ~1×10 10 CFU / mL.

[0015] In some embodiments, the concentration of the Lactobacillus pentosus ZY1 suspension can be 1×10 9 CFU / mL.

[0016] In some embodiments, the inoculation amount of the Lactobacillus pentosus ZY1 bacterial suspension may be 1% (v / v).

[0017] In some embodiments, the fermentation temperature may be 20-40° C., and the fermentation time may be 2-6 days.

[0018] In some embodiments, the fermentation temperature may be 30° C. and the fermentation time may be 6 days.

[0019] The beneficial effects of the present invention include: (1) The Lactobacillus pentosus ZY1 provided by the present invention not only has high nitrite degradation activity but also has salt tolerance, and is suitable for preparing kimchi, and the prepared kimchi has good flavor.

[0020] (2) The Lactobacillus pentosus ZY1 provided by the present invention has a fast acid production rate, simple culture conditions, is easy to industrialize, and has good development and application prospects.

[0021] (3) The Lactobacillus pentosus ZY1 provided by the present invention is inoculated into kimchi for fermentation. The Lactobacillus pentosus ZY1 can quickly take the leading position and become the dominant bacterial group, forming a stable microbial community, thereby effectively solving the problem of disorderly microbial growth in kimchi and improving the quality and safety of fermented kimchi.

[0022] (4) The Lactobacillus pentosus ZY1 provided by the present invention can be used to ferment kimchi to effectively reduce the peak nitrite content (reduced by 66.99% compared with natural fermentation), and the pH can be maintained at 3.40-3.60. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 For the present invention Lactiplantibacillus pentosus Colony morphology of strain ZY1; Figure 2 For the present invention Lactiplantibacillus pentosus Bacterial morphology of ZY1 strain. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below with reference to the following embodiments. The examples are provided for illustrative purposes only and are not intended to limit the present invention in any way. Unless otherwise specified, the raw materials and reagents used in the examples are commercially available conventional products. Experimental procedures in the examples where specific conditions are not specified are generally performed in accordance with conventional conditions in the art or the conditions recommended by the manufacturer.

[0025] In the embodiment of the present invention: (1) Gram staining, shape observation and commonly used physiological and biochemical identification culture media refer to "Classification, Identification and Test Methods of Lactic Acid Bacteria" edited by Ling Daiwen, China Light Industry Press, 1999 edition.

[0026] (2) MRS liquid medium (g / L) (for the culture of lactic acid bacteria): 10.0 g of casein digest, 10.0 g of beef extract powder, 4.0 g of yeast extract powder, 2.0 g of triammonium citrate, 5.0 g of sodium acetate, 0.2 g of magnesium sulfate (MgSO4·7H2O), 0.05 g of manganese sulfate (MnSO4·4H2O), 2.0 g of dipotassium hydrogen phosphate, 20.0 g of glucose, and 1.0 g of Tween-80 were added to 1 L of distilled water and the pH was adjusted to 5.7 ± 0.2 (MRS solid medium is prepared by adding 1.5% agar to the liquid medium). Sterilize at 121°C for 15 min.

[0027] (3) Determination of nitrite content: Preparation of the standard curve: Pipette 0.00 mL, 0.80 mL, 1.60 mL, 4.00 mL, 5.00 mL, 6.00 mL, 8.00 mL, and 10.00 mL of the sodium nitrite working solution (5 µg / mL) into 25 mL colorimetric tubes for testing.

[0028] Sample pretreatment: Weigh 5 g of sample into a centrifuge tube and add borax solution (50 g / L) preheated to 75°C. Incubate at 75°C for 15 minutes. After cooling, add potassium ferrocyanide solution (106 g / L) and zinc acetate solution (220 g / L) sequentially. Let stand for 30 minutes to precipitate the protein. The pretreatment reagents are added to the sample, borax solution, potassium ferrocyanide solution, and zinc acetate solution in a volume ratio of 1:2.5:1:1. After centrifugation at 4000 rpm for 10 minutes to separate the precipitate, transfer 2 mL of the supernatant to a 25 mL colorimetric tube as the sample for analysis.

[0029] Determination and color development system: Add p-aminobenzenesulfonic acid solution (4 g / L), naphthaleneethylenediamine hydrochloride solution (2 g / L) and distilled water to each test tube in sequence. The color development reagents are added to the sample, p-aminobenzenesulfonic acid solution, naphthaleneethylenediamine hydrochloride solution and distilled water in a volume ratio of 2:2:1:20. After adding p-aminobenzenesulfonic acid solution and distilled water, react for 5 minutes and 15 minutes respectively before proceeding with subsequent operations. After color development is completed, transfer 200 μL of the reaction solution to a 96-well plate and measure OD540. The nitrite degradation rate is calculated according to formulas (1) and (2) and the reagent blank is used as a reference.

[0030] (1) in, X is the nitrite content of the sample (calculated as sodium nitrite), mg / kg; m1 is the mass of sodium nitrite sample added to the colorimetric tube, μg; V 2 is the sample processing volume, mL; 1000 is the conversion factor; m 2 is the mass of the sample weighed, g; V 1 is the volume of the sample added to the colorimetric tube, mL.

[0031] (2) in, X is the nitrite degradation rate, %; A is the nitrite content of the blank sample, μg / mL; B is the nitrite content of the treatment group, μg / mL.

[0032] (4) The determination methods of total colony count and viable lactic acid bacteria count shall refer to GB 4789.2-2022 “National Food Safety Standard - Microbiological Examination of Foods - Determination of Total Colony Count” and GB4789.35-2016 “National Food Safety Standard - Microbiological Examination of Foods - Lactic Acid Bacteria”.

[0033] Example 1: Screening and identification of bacterial strains 1. Sampling and plate separation Use sterile sampling bottles to collect Sichuan naturally fermented sour cowpea from the market, and immediately dilute to 10 with sterile water. -3 , 10 -4 , 10 -5 The strain was then spread onto MRS solid medium at 100 μg / ml and placed in a 37°C constant temperature incubator for 48 hours. Suspected colonies were picked and streaked onto the plate. This process was repeated 4-5 times until a pure single colony was obtained. The purified single colony was named ZY1. The purified single colony was inoculated into MRS solid medium and stored in a refrigerator at 4°C.

[0034] 2. Morphological observation and physiological and biochemical experiments like Figures 1 - 2 As shown, on the MRS solid medium plate, the colonies of strain ZY1 are protruding, round, generally 1-3 mm in diameter, off-white, opaque, moist and smooth ( Figure 1 ), the bacteria are Gram-positive non-spore-forming bacilli, in the shape of thin short rods, arranged in pairs or piles ( Figure 2 ).

[0035] The results of routine physiological and biochemical experiments are shown in Table 1. The results in Table 1 show that strain ZY1 is Gram-positive, catalase-negative, hemolysis-negative, and non-motile.

[0036] Table 1 Physiological and biochemical characteristics of strain ZY1

[0037] 3. Molecular identification The strain ZY1 was activated and cultured, and then sent to a professional testing agency for sequencing to obtain the 16S rDNA sequence (the specific sequence is shown in SEQ NO: 1). The results were compared with the NCBI gene library, and a standard strain CP032757.1 with a close relationship to the strain ZY1 was found ( Lactiplantibacillus pentosus strain DSM 20314), PV164899.1 ( Lactiplantibacillus pentosus strain P7) and KT215616.1 ( Lactiplantibacillus pentosus strain FL0421), and the 16S rDNA of strain ZY1 was analyzed for similarity with the standard strain. The results are shown in Table 2. Lactiplantibacillus pentosus The sequence homology of strain DSM 20314 is 100.00%, indicating that they are the same species.

[0038] Table 2 BLAST sequence alignment of strain ZY1 based on 16S rDNA sequence

[0039] Further obtain two housekeeping genes of strain ZY1 recA Sequence (specific sequence is shown in SEQ NO: 2) and pheS The specific sequence is shown in SEQ NO: 3, and the similarity between it and the standard bacteria was analyzed. recA Lactobacillus pentosus Lactiplantibacillus pentosus strain DSM 20314 sequence homology was 100.00% (Table 3), and strain ZY1 pheS Lactobacillus pentosus Lactiplantibacillus pentosus strain DSM20314 sequence homology was 100.00% ( Table 4 ).

[0040] Table 3 Strain ZY1 according to housekeeping genes recA BLAST sequence alignment table of the sequence

[0041] Table 4 Strain ZY1 according to housekeeping genes pheS BLAST sequence alignment table of the sequence

[0042] The molecular identification results combined with the colony, bacterial morphology and physiological and biochemical characteristics can identify strain ZY1 as Lactobacillus pentosus ( Lactiplantibacillus pentosus ), named it Lactobacillus pentosus ( Lactiplantibacillus pentosus )ZY1.

[0043] The strain is deposited in the Guangdong Provincial Microbiological Culture Collection Center, located at the Guangdong Provincial Microbiological Culture Collection Center, 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou. The deposit number is GDMCC No. 66473, and the deposit date is June 6, 2025.

[0044] Example 2: Determination of nitrite-reducing activity of Lactobacillus pentosus ZY1 (1) Preparation of bacterial suspension Take a 10 mL test tube, add 10 mL of MRS liquid medium, sterilize at 121°C for 15 min, pick a single colony of Lactobacillus pentosus ZY1 and inoculate it into MRS liquid medium, and culture at 36°C for 24 h. Then inoculate 1% (v / v) Lactobacillus pentosus ZY1 into 10 mL of MRS liquid medium and culture at 36°C for 24 h. After the culture is completed, the bacterial concentration is adjusted to 1×10 9 CFU / mL, and obtain the bacterial suspension of Lactobacillus pentosus ZY1.

[0045] (2) Preparation of MRS medium containing nitrite Prepare 1500 μg / mL nitrite solution, filter through a 0.22 μm sterile filter membrane, and store at 4°C.

[0046] Take a 10 mL test tube, add 9 mL of MRS liquid medium, sterilize at 121°C for 15 min, cool, and add 1 mL of 1500 μg / mL sterile nitrite solution to prepare MRS medium containing 150 μg / mL nitrite.

[0047] (3) Preparation of vegetable juice culture medium containing nitrite Select fresh, undamaged, and non-moldy milk cabbage, take 750 g of milk cabbage, wash and beat it, 8000× g Centrifuge for 10 minutes, remove the supernatant, and sterilize at 121°C for 15 minutes. After cooling, add 4.5 mL of sterile vegetable juice to 4.5 mL of sterile MRS liquid medium, followed by 1 mL of 1500 μg / mL sterile nitrite solution to prepare a vegetable juice medium containing 150 μg / mL nitrite.

[0048] (4) Determination of nitrite-reducing activity The suspension of Lactobacillus pentosus ZY1 prepared in step (1) was inoculated with 1% (v / v) into MRS medium and vegetable juice medium containing nitrite, and cultured at 36°C for 24 h. The nitrite content was analyzed using MRS and vegetable juice medium as reagent blanks and MRS and vegetable juice medium containing 150 μg / mL sodium nitrite as sample blanks.

[0049] The test results showed that after 24 h of fermentation, the degradation rate of nitrite by Lactobacillus pentosus ZY1 in MRS medium containing 150 μg / mL nitrite was 97.6%, and the degradation rate of nitrite in vegetable juice medium containing 150 μg / mL nitrite was 84.7%.

[0050] Example 3: Salt tolerance of Lactobacillus pentosus ZY1 (1) Preparation of bacterial suspension Take a 10 mL test tube, add 10 mL of MRS liquid medium, sterilize at 121°C for 15 min, pick a single colony of Lactobacillus pentosus ZY1 and inoculate it into MRS liquid medium, and incubate it at 36°C for 24 h. Then inoculate Lactobacillus pentosus ZY1 into 10 mL of MRS liquid medium at 1% (v / v) and incubate it at 36°C for 24 h. After the incubation period, adjust the bacterial concentration to 1×10 9 CFU / mL, and obtain the bacterial suspension of Lactobacillus pentosus ZY1.

[0051] (2) Preparation of nitrite and sodium chloride MRS culture medium Take a 10 mL test tube, add 9 mL of MRS liquid medium, sterilize at 121°C for 15 min, cool, and add sterile nitrite solution to prepare MRS medium containing 0-500 μg / mL nitrite.

[0052] Take a 10 mL test tube, add 10 mL of MRS liquid medium, add 0-7.5% (w / v) NaCl, sterilize at 121°C for 15 min, and cool to prepare MRS medium containing 0-7.5% (w / v) NaCl.

[0053] (3) Salt tolerance test 1% (v / v) of the suspension of Lactobacillus pentosus ZY1 prepared in step (1) was inoculated into the MRS medium containing nitrite and the MRS medium containing NaCl, respectively, and cultured at 36°C for 24 h. The absorbance of the culture solution (OD 600 ) were used to evaluate the growth of Lactobacillus pentosus ZY1 and determine its tolerance to the two salts.

[0054] The results are shown in Tables 5 and 6. Lactobacillus pentosus ZY1 grew well in the nitrite concentration range of 0–300 μg / mL (Table 5), with a survival rate greater than 93%. It also grew well in the NaCl concentration range of 0–5% (w / v) (Table 6), with a survival rate greater than 98%, demonstrating good salt tolerance.

[0055] Table 5 Growth of Lactobacillus pentosus ZY1 strain under different nitrite concentrations

[0056] Table 6 Growth of Lactobacillus pentosus ZY1 strain under different NaCl concentrations

[0057] Example 4: Preparation of low-nitrite kimchi using lactobacillus pentosus ZY1 to ferment milk cabbage (1) Seed solution preparation Take a 10 mL test tube, add 10 mL of MRS liquid medium, sterilize at 121℃ for 15 min, pick a single colony of Lactobacillus pentosus ZY1 and inoculate it into MRS liquid medium, and culture it at 36℃ for 24 h; then inoculate 1% (v / v) Lactobacillus pentosus ZY1 into 50 mL of MRS liquid medium, and culture it at 36℃ for 24 h. g The cells were centrifuged for 10 min to obtain the cells, which were resuspended in sterile saline and the concentration of the bacterial solution was adjusted to 1 × 10 9 CFU / mL, and the seed liquid of Lactobacillus pentosus ZY1 was obtained.

[0058] (2) Fermented milk cabbage (inoculated fermentation) S1. Dissolve 5% (w / v) sodium chloride in 1.5 L of purified water and sterilize at 121°C for 20 minutes.

[0059] S2. Inoculate 1.5 L of sterilized sodium chloride solution with 1% (v / v) of the Lactobacillus pentosus ZY1 seed solution of step (1), and then add rice vinegar and cooking wine at 1% (v / v) of the volume of the sodium chloride solution to obtain a fermentation liquid.

[0060] S3. Select fresh, undamaged, and non-moldy Chinese cabbage, take 750 g of the Chinese cabbage, wash it, separate the leaves, and divide it into bottles. Add fermentation liquid, then seal it with plastic wrap and ferment it at 30°C for 6 days.

[0061] The positive control was natural fermentation, that is, no inoculation of the Lactobacillus pentosus ZY1 seed solution was performed, and the remaining steps were the same.

[0062] (3) Analysis of nitrite content At 0, 6, 12, 18, 24, 30, 36, 42, 48, 96, and 144 h of kimchi fermentation, 5 g of kimchi leaves were collected, mixed and crushed, and the nitrite content was determined.

[0063] The results are shown in Table 7.

[0064] After testing, the nitrite content continued to rise from 0 to 6 hours of inoculation and fermentation, reaching a small peak of 5.04±1.01 mg / kg at 6 hours, and decreased significantly from 6 to 18 hours. After 18 hours, it basically remained at a low level (<1 mg / kg), with no obvious fluctuations thereafter. During the entire fermentation process, the national nitrite limit standard of 20 mg / kg was not exceeded.

[0065] During natural fermentation, the nitrite content increased rapidly from 0 to 12 hours, reaching a peak of 15.27±6.11 mg / kg at 12 hours. Its fluctuation range exceeded the national limit of 20 mg / kg, posing a certain safety risk. It continued to decline from 12 to 48 hours, eventually reaching a low level (<1 mg / kg).

[0066] The peak of inoculated fermentation (6 h) appeared earlier than that of natural fermentation (12 h), and the peak nitrite content was reduced by about 66.99% compared with that of natural fermentation.

[0067] Table 7 Changes in nitrite content in fermented Chinese cabbage inoculated with Lactobacillus pentosus ZY1

[0068] (4) Microbial count and pH determination The fermentation broth was collected at 0, 48, 96, and 144 h of kimchi fermentation for viable microbial count. The total colony count was counted using PCA agar medium, the viable lactic acid bacteria count was counted using MRS agar medium, and the pH value was measured using a pen-type acidometer.

[0069] The results are shown in Tables 8 to 10.

[0070] The total colony count (CCC) test results (Table 8) showed that the initial CCC value of the fermented Chinese cabbage inoculated with Lactobacillus pentosus ZY1 was high (7.42 log CFU / mL), but remained stable above 7 log CFU / mL throughout the fermentation period. The CCC value of the naturally fermented Chinese cabbage was low (5.96 log CFU / mL) and showed an initial increase, decrease, and then increase again during the fermentation period. The CCC value fluctuated significantly after 96 hours (decreasing to 6.9 log CFU / mL), indicating intense competition and instability within the bacterial community.

[0071] The results of viable lactic acid bacteria count testing (Table 9) showed that the initial viable lactic acid bacteria count in the fermented kimchi inoculated with Lactobacillus pentosus ZY1 was high (7.41 log CFU / mL). This count increased during the early stages of fermentation and remained stable above the initial count during the later stages. This indicates that after inoculation with Lactobacillus pentosus ZY1, lactic acid bacteria rapidly established a stable microbial community in the kimchi system, becoming the dominant bacterial community and inhibiting the growth of other bacteria. The original bacterial community of naturally fermented kimchi was low in lactic acid bacteria (2.82 log CFU / mL). After 48 hours, the viable lactic acid bacteria count remained similar to that of the inoculated fermentation, but was significantly affected by the natural bacterial community, with a significant fluctuation after 96 hours (decreasing to 7.21 log CFU / mL). This suggests that the dominant position of the lactic acid bacteria in the naturally fermented kimchi was difficult to establish and the bacterial community was insufficiently stable.

[0072] The pH of kimchi can be used to measure the quality of finished kimchi, with a pH between 3.20 and 3.80 considered acceptable. The pH test results for fermented kimchi (Table 10) show that in fermented kimchi inoculated with Lactobacillus pentosus ZY1, lactic acid bacteria rapidly proliferated and produced significant acid in the early stages, with the pH decreasing as the number of viable lactic acid bacteria increased. Later, the number of viable lactic acid bacteria remained stable at a high level, and the pH also remained stable between 3.40 and 3.60, meeting kimchi quality standards. The pH of naturally fermented kimchi initially reached 4.01, then decreased and then increased during fermentation. Due to the instability of the naturally fermented bacterial community, lactic acid bacteria were not dominant, and their acid production capacity was limited, preventing them from continuously suppressing other bacterial communities. This allowed other microorganisms (contaminants) to participate in the fermentation process, leading to a continuous pH increase, reaching 4.03 at 144 hours, which no longer met kimchi quality standards.

[0073] Table 8 Changes in the total colony count of fermented Chinese cabbage inoculated with Lactobacillus pentosus ZY1

[0074] Table 9 Changes in the number of viable lactic acid bacteria in fermented cabbage inoculated with Lactobacillus pentosus ZY1

[0075] Table 10 Changes in pH value of fermented Chinese cabbage inoculated with Lactobacillus pentosus ZY1

[0076] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, which all fall within the scope of protection of the present invention.

Claims

1. A strain of Lactobacillus pentosus, characterized in that Lactobacillus pentosus ( Lactiplantibacillus pentosus )ZY1, the deposit number is GDMCC No.66473.

2. A bacterial agent, characterized in that The bacterial agent contains the Lactobacillus pentosus according to claim 1.

3. Use of the Lactobacillus pentosus according to claim 1 or the bacterial agent according to claim 2 in reducing the nitrite content in fermented products.

4. Use of the Lactobacillus pentosus according to claim 1 or the bacterial agent according to claim 2 in the production of fermentation products.

5. The use according to claim 4, characterized in that The fermented product is kimchi.

6. The use according to claim 5, characterized in that The fermentation raw material of the kimchi is selected from at least one of Chinese cabbage, cowpea, celery, mustard, Chinese cabbage, kale, carrot, white radish, pepper and cucumber.

7. A method for preparing low-nitrite kimchi by fermenting milk cabbage with the Lactobacillus pentosus according to claim 1, characterized in that: The steps include: The milk cabbage, the bacterial suspension of Lactobacillus pentosus according to claim 1, sodium chloride solution and seasoning are added into a fermentation device for fermentation to obtain the product.

8. The method according to claim 7, characterized in that The steps include: A sodium chloride solution with a concentration of 1-7.5% (w / v) is sterilized and inoculated with a 1-5% (v / v) bacterial suspension of the Lactobacillus pentosus according to claim 1, and then rice vinegar and cooking wine are added in an amount of 0.5-1.5% (v / v) based on the volume of the sodium chloride solution, respectively, to obtain a fermentation liquid; The method comprises adding the milk cabbage into a fermentation device, then adding fermentation liquid, sealing the device and performing fermentation to obtain the product.

9. The method according to claim 7 or 8, characterized in that The concentration of the bacterial suspension was 1×10 8 ~1×10 10 CFU / mL.

10. The method according to claim 9, characterized in that The fermentation temperature is 20-40° C., and the fermentation time is 2-6 days.

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