Lactobacillus brevis and application thereof

Abstract

The invention provides lactobacillus brevis and application thereof, the lactobacillus brevis is lactobacillus brevis RJS1401, is preserved in the China Center for Type Culture Collection in Wuhan on October 22, 2024, and has the preservation number of CCTCC NO: M 20242296. The lactobacillus brevis is lactobacillus brevis RJS1401, is preserved in the China Center for Type Culture Collection in Wuhan on October 22, 2024, and has the preservation number of CCTCC NO: M 20242296. The strain can effectively degrade organophosphorus and nitrite, shows good stress resistance and gamma-aminobutyric acid (GABA) production capacity, and has a remarkable peculiar smell modification effect; the method can be applied to preparation of edible plant enzymes, pickled vegetables and other products.

Description

[Technical field]

[0001] The invention relates to the technical field of microorganisms, and in particular to a growth-promoting lactobacillus breve and an application thereof. [Background technology]

[0002] Edible plant enzymes are edible enzyme products containing specific biologically active ingredients, which are made from fruits, vegetables and grains that can be used for food processing as the main raw materials, with or without auxiliary materials, and are fermented by microorganisms. They are rich in nutrients such as vitamins, enzymes and minerals, and have multiple health benefits such as optimizing the intestinal environment, anti-oxidation, weight loss and detoxification, and antibacterial and anti-inflammatory. However, some raw materials such as noni fruit, celery, and garlic contain odors that are difficult to be widely accepted, which limits the further development of these high-quality resources. Microbial fermentation is a key link in enzyme production. Currently, commonly used strains include yeast, lactic acid bacteria, acetic acid bacteria and molds; these bacteria can improve or eliminate the unpleasant flavor of the fermentation matrix and produce new functional ingredients. Therefore, the type of strain and its performance are crucial to the quality of the enzyme.

[0003] Pickled vegetables are popular among consumers for their unique flavor and taste. However, nitrite is inevitably produced during the pickling process of vegetables. It is a precursor of the carcinogen nitrosamine, so pickled vegetables have potential safety risks. There are mainly physical, chemical and biological methods to degrade nitrite. Among them, microbial degradation has attracted much attention due to its high efficiency and safety. It uses microorganisms that can degrade nitrite or the nitrite reductase they produce to reduce the nitrite content, thereby improving product quality and safety.

[0004] In addition, the pesticides commonly used in the cultivation of vegetables and fruits are mostly organophosphorus compounds. If not handled properly, they may lead to drug residues and enter the human body through the food chain, causing chronic neurotoxicity. Therefore, screening for excellent strains with the activity of degrading organophosphorus and nitrite is of great significance for the safe production of fermented products using fruits and vegetables as raw materials. [Summary of the invention]

[0005] The technical problem to be solved by the present invention is to provide a short growth-promoting lactobacillus and its application, which can effectively degrade organic phosphorus and nitrite, show good stress resistance and γ-aminobutyric acid (GABA) production ability, and have significant odor modification effect; it can be used in the preparation of edible plant enzymes, pickled vegetables and other products.

[0006] The present invention is achieved in that:

[0007] A breve lactobacillus, wherein the breve lactobacillus is brevis lactobacillus (Levilactobacillusbrevis) RJS1401, which was preserved in the China Center for Type Culture Collection in Wuhan on October 22, 2024, with a preservation number of CCTCC NO: M 20242296.

[0008] Furthermore, the application of the Lactobacillus breve RJS1401 in edible plant enzymes.

[0009] Furthermore, the application of the Lactobacillus breve RJS1401 in native grape enzymes.

[0010] Furthermore, the application of the Lactobacillus breve RJS1401 in modifying the off-flavor of noni fruit.

[0011] Furthermore, the application of the Lactobacillus breve RJS1401 in the processing of pickled vegetables.

[0012] The present invention has the following advantages:

[0013] The short growth-promoting Lactobacillus RJS1401 of the present invention can effectively degrade organic phosphorus and nitrite, exhibits good stress resistance and GABA production ability, and has a significant odor modification effect; the strain can effectively degrade nitrite produced in the preparation process of pickled vegetables, so that the nitrite of the prepared product is maintained at a low level, and the product has rich layers and bright colors; the bacteria provides a new probiotic resource for the development of edible plant enzymes, pickled vegetables and other products.

Brief Description of the Drawings

[0014] The present invention will be further described below in conjunction with embodiments with reference to the accompanying drawings.

[0015] Figure 1 Schematic diagram of the phosphate solubilization ability of the test strains according to the embodiments of the present invention.

[0016] Figure 2 This is a schematic diagram of the GABA thin layer chromatography of the fermentation liquid of the test strain in an embodiment of the present invention.

[0017] Figure 3 Schematic diagram of the colony morphology of strain RJS1401 according to an embodiment of the present invention.

[0018] Figure 4 Schematic diagram of the cell morphology (light microscope, ×1000) of the strain RJS1401 of the example of the present invention.

[0019] Figure 5 Schematic diagram of the phylogenetic tree of strain RJS1401 according to an embodiment of the present invention.

[0020] Figure 6Schematic diagram of the growth and acid production curve of strain RJS1401 according to an embodiment of the present invention.

[0021] Figure 7 This is a schematic diagram of the growth of strain RJS1401 at different temperatures according to an embodiment of the present invention.

[0022] Figure 8 This is a schematic diagram of the growth of strain RJS1401 at different pH values ​​according to an embodiment of the present invention.

[0023] Fig. 9 This is a schematic diagram of the growth of strain RJS1401 of an embodiment of the present invention under different NaCl concentrations.

[0024] Fig.10 Schematic diagram of GABA content (top) and SOD activity (bottom) in different treated samples according to an embodiment of the present invention.

[0025] Fig.11 Schematic diagram of nitrite content in different treated samples according to an embodiment of the present invention. [Specific implementation method]

[0026] The present invention relates to a breve lactobacillus, which is Levilactobacillus brevis RJS1401, which was deposited in the China Center for Type Culture Collection in Wuhan on October 22, 2024, with a deposit number of CCTCC NO: M 20242296.

[0027] The present invention also relates to one of the applications of Lactobacillus breve, namely, the application of Lactobacillus breve RJS1401 in edible plant enzymes.

[0028] Specifically, the application of the Lactobacillus breve RJS1401 in native grape enzymes.

[0029] The present invention also relates to a second application of Lactobacillus breve, which is the application of Lactobacillus breve RJS1401 in modifying the off-flavor of noni fruit.

[0030] The present invention further relates to a third application of Lactobacillus breve, which is the application of the Lactobacillus breve RJS1401 in the processing of pickled vegetables.

[0031] The following will be combined with the attached Figure 1-11The technical scheme of the present invention is clearly and completely described in detail with specific embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0032] Example 1 Acquisition of strain RJS1401

[0033] 1 Materials and methods

[0034] 1.1 Materials

[0035] 1.1.1 Sample: Green plum wine, collected from a winery in Fuzhou, Fujian Province.

[0036] 1.1.2 Culture medium: (1) MRS culture medium: finished product, Beijing Luqiao Technology Co., Ltd.; (2) Organophosphorus culture medium: glucose 10 g / L, (NH4)2SO4 0.5 g / L, NaCl 0.3 g / L, KCl 0.3 g / L, FeSO4 0.03 g / L, MnSO4 0.03 g / L, CaCO3 5 g / L, soybean lecithin 0.2 g / L, agar 2.0%, pH 6.8 ± 0.2, sterilized at 115 ° C for 15 min; (3) GABA-producing culture medium: add 1% L-glutamic acid to MRS.

[0037] 1.2 Methods

[0038] 1.2.1 Strain isolation and screening

[0039] (1) Isolation and purification of strains: Take 5 mL of the sample and add it to a 250 mL Erlenmeyer flask containing 45 mL of sterile water and shake well. Take 1 mL of the sample solution and perform a 10-fold gradient dilution. Select the appropriate dilution according to actual needs. Take 0.2 mL of each dilution and spread it on an MRS plate. Incubate the plate anaerobically at 30°C. After the colonies grow, select colonies with typical lactic acid bacteria characteristics and good growth, and further isolate and purify them until a pure strain is obtained for later use.

[0040] (2) Nitrite degradation ability: The seed liquid of the strain to be tested was inoculated with 5% (v / v) in 20 mL of nitrite MRS medium (MRS medium containing 200 μg / mL NaNO2), and cultured at 35°C for 48 h. The fermentation liquid was centrifuged at 4°C and 9000 r / min for 10 min, 1 mL of supernatant was aspirated, and the nitrite content was determined using the nitrite determination kit (colorimetric method) produced by Nanjing Jiancheng Bioengineering Research Institute, and the nitrite degradation rate was calculated. The nitrite degradation rate calculation formula is: X = (N2-N1) / N2×100%; where: X represents the nitrite degradation rate, %; N1 represents the nitrite content in the culture medium of the inoculated strain, μg / mL; N2 represents the nitrite content in the culture medium of the uninoculated strain, μg / mL.

[0041] (3) Organic phosphorus degradation ability: The spot culture method was used. Using a sterilized toothpick, the strain to be tested was spot-inoculated on an organic phosphorus solid culture medium plate with lecithin as the only phosphorus source. Three spots were inoculated on each plate. Three groups of parallel tests were performed. The plates were cultured at 30°C for 7 days. The formation of a transparent zone was observed, and the diameter of the transparent zone (including the colony, A) and the diameter of the colony (B) were measured. The phosphorus solubilization index (A / B) was calculated. An index greater than 1 indicated that the strain had phosphorus solubilization activity on the plate.

[0042] (4) GABA production capacity: a) Thin layer chromatography: The activated strain of the strain to be tested was inoculated into the GABA production medium at 5% (v / v) and cultured at 30°C for 48h; 1mL of the culture solution was centrifuged at 9000r / min and 4°C for 15min, the bacterial precipitate was discarded, and the supernatant was taken for standby use. 1μL of the supernatant of the test sample was taken and spotted on a G-type thin layer silica gel plate; the developing agent was prepared according to the volume ratio of n-butanol: glacial acetic acid: ultrapure water = 4:1:3, and a 0.4% mass fraction of ninhydrin-ethanol mixed solution was added to the developing agent as a color developer, and the chromatography plate was placed steadily, protected from light, and sealed until the developing agent expanded to 1cm from the upper edge of the silica gel plate, and then taken out and color developed in a 90-100°C oven for 15min. At the same time, the diluted GABA standard solution was used as a control. After color development, if spots appear in the sample column and the spot position is on the same horizontal line as the GABA standard, it proves that the lactic acid bacteria fermentation broth contains GABA. b) Berthelot colorimetric method: Take the fermentation broth of the strain cultured in GABA medium as the sample, measure the GABA concentration in it, and compare the GABA production capacity of each strain to be tested.

[0043] 1.2.2 Strain identification

[0044] (1) Morphological observation

[0045] The target strain was inoculated onto an MRS plate and cultured at 30°C for 2-3 days, and the colony morphology was observed every day. A small amount of culture was picked and observed under a microscope for bacterial cell morphology. The strain was preliminarily classified.

[0046] (2) Gene sequence analysis

[0047] The genomic DNA of the target strain was extracted using a bacterial gene DNA extraction kit, and the genomic DNA was used as a template. The primers 27F (5'-AGAGTTTGATCCTGGCTCAG-3' (as shown in SEQ ID NO.1)) and 1492R (5'-CTACGGCTACCTTGTTACGA-3' (as shown in SEQ ID NO.2)) were used for PCR amplification, and the PCR amplification products were detected by 1% agarose gel electrophoresis. The purified PCR amplification products were sequenced, and the obtained sequences were compared for homology using BLAST in the GenBank database of NCBI. The sequences of strains with higher homology were selected, and the phylogenetic tree was constructed using the Neighbor-Joining (NJ) method in MEGA4.0 software.

[0048] 2 Results and analysis

[0049] 2.1 Isolation and screening of lactic acid bacteria strains

[0050] A total of 10 lactic acid bacteria strains were isolated from the green plum wine sample. The strain numbers and their characteristics of nitrite degradation, phosphate solubilization and GABA production are as follows: Figure 1 , 2 As shown in Table 1. Among the 10 strains, RJS1301 had the highest nitrite degradation rate of 97.1%, followed by RJS1401 with 96.9% (Table 1). The phosphate solubilization ability of the 6 strains with nitrite degradation rates of more than 85% was further evaluated. The results showed that RJS1401 had the highest phosphate solubilization index of 3.11, followed by RJS1403 ( Figure 1 and Table 1). At the same time, the fermentation broths of the 10 strains were qualitatively analyzed by thin layer chromatography, and the results showed that ( Figure 2 ), only RJS1303 and RJS1401 had the same ratio shift value as the GABA standard, and it was preliminarily determined that both strains produced GABA. Further quantitative analysis found (Table 1) that the GABA production of RJS1401 and RJS1303 was 0.92 and 0.64 mg / mL, respectively. Based on these results, RJS1401 is a lactic acid bacterium with high GABA production and good ability to solubilize phosphate and degrade nitrite.

[0051] Table 1 Performance evaluation of the tested strains

[0052]

[0053] Note: “-” means not detected, “ / ” means not detected.

[0054] 2.2 Species identification of target strains

[0055] 2.2.1 Macroscopic and microscopic morphological characteristics of RJS1401

[0056] The morphological characteristics of strain RJS1401 are as follows Figure 3 , 4 In MRS medium, cultured at 30℃ for 2 days, the colonies were small, round, milky white, smooth, moist, opaque, and with neat edges. Under an optical microscope, Gram-positive cells were short rod-shaped, 0.50μm×1.05-1.33μm, arranged singly, in pairs or in short chains, and did not produce spores.

[0057] 2.2.2 Gene sequence analysis of RJS1401

[0058] The length of the 16S rDNA sequence of RJS1401 is 1440 bp (as shown in SEQ ID NO.3). The sequencing results were compared with BLAST in NCBI for homology, and the phylogenetic tree was constructed using MEGA 4.1. Figure 5 , RJS1401 and Levilactobacillus brevis clustered on the same branch, and the homology was as high as 100%. Combined with the morphological characteristics of RJS1401, it was determined that the bacterium was Levilactobacillus brevis, which was deposited in the China Center for Type Culture Collection in Wuhan on October 22, 2024, with the deposit number CCTCC NO: M 20242296.

[0059] Example 2 Study on biological characteristics of strain RJS1401

[0060] 1 Materials and methods

[0061] 1.1 Materials

[0062] 1.1.1 Bacterial strain: Lactobacillus breve RJS1401, with the deposit number of CCTCC NO: M 20242296. 1.1.2 MRS culture medium: finished product, Beijing Luqiao Technology Co., Ltd.

[0063] 1.2 Methods

[0064] 1.2.1 Growth and acid production curve

[0065] Lactobacillus breve RJS1401 (10 8CFU / mL, the same below) was inoculated into MRS liquid medium at 5% (v / v), and cultured at 30°C. The blank medium without inoculation was used as the control for synchronous treatment. Samples were taken every 3 hours to detect the biomass (OD 600 ) and pH value, and draw the strain growth and acid production curve.

[0066] 1.2.2 Effect of temperature on strain growth

[0067] Lactobacillus breve RJS1401 was inoculated into MRS liquid medium at 5% (v / v) and cultured at 25°C, 30°C, 35°C, and 40°C for 15 h. The blank medium without inoculation was used as a control for synchronous treatment. The biomass (OD 600 ) to analyze the effect of culture temperature on strain growth.

[0068] 1.2.3 Acid resistance

[0069] Lactobacillus breve RJS1401 was inoculated into MRS liquid culture medium with different pH values ​​(2, 3, 4, 5, 6) at 5% (v / v) and cultured at 35°C for 15 h. The blank culture medium without inoculation at the corresponding pH value was used as a control for synchronous treatment. The biomass (OD 600 ) to analyze the acid resistance of the strain and the suitable pH value for growth.

[0070] 1.2.4 Salt tolerance

[0071] Lactobacillus breve RJS1401 was inoculated into MRS liquid culture medium with different NaCl concentrations (0, 3, 6, 9, 12, 15, 18, 21%) at 5% (v / v) and cultured at 35°C for 15 h. The blank culture medium without inoculation of the corresponding NaCl concentration was used as a control for synchronous treatment. The biomass (OD 600 ) to analyze the salt tolerance of the strains.

[0072] 2 Results and analysis

[0073] 2.1 Growth and acid production curve of strain RJS1401

[0074] The growth and acid production of strain RJS1401 in MRS liquid medium are as follows Figure 6 As shown. RJS1401 has no obvious lag phase, which may be because the bacteria are inoculated and cultured after activation, and the bacteria have strong vitality; the strain enters the logarithmic growth phase at 3-15h, with a fast growth rate, and then enters the stable phase. During the entire growth process, the pH value of the fermentation liquid shows a continuous downward trend, and the rate of decline is basically consistent with the growth rate, that is, the rapid growth period of the strain is also the rapid acid production period.

[0075] 2.2 Effect of temperature on the growth of strain RJS1401

[0076] The growth of strain RJS1401 at different temperatures is shown in Figure 7 As shown in the figure, within the range of 25-40℃, as the fermentation temperature increased, the growth of RJS1401 first increased and then decreased, indicating that lower or higher temperatures were not suitable for the growth and reproduction of the strain, and the bacterial growth reached the maximum at 35℃.

[0077] 2.3 Acid resistance of strain RJS1401

[0078] The proliferation of strain RJS1401 under different pH conditions is shown in Figure 8 As shown. Under pH 2.0, the bacteria still have a small amount of proliferation, indicating that the bacteria can tolerate higher acidity; as the pH value continues to increase, the bacterial count continues to increase, reaching the maximum under pH 5.0, and then slightly decreasing; therefore, RJS1401 is suitable for growth in a slightly acidic environment.

[0079] 2.4 Salt tolerance of strain RJS1401

[0080] The growth of strain RJS1401 under different salinities is shown in Fig. 9 As shown in the figure, with the increase of NaCl concentration in the culture medium, the proliferation of RJS1401 showed a downward trend, and only a slight proliferation or the initial bacterial count was maintained in the culture medium with 18% NaCl, indicating that the bacteria can tolerate 18% salinity.

[0081] Example 3 Application of strain RJS1401 (I) Application of strain RJS1401 in the preparation of native grape enzyme

[0082] 1 Materials and methods

[0083] 1.1 Materials

[0084] 1.1.1 Strains: (1) Lactobacillus breve RJS1401, self-screened strain, with a deposit number of CCTCC NO.M20242296; (2) Kluyveromyces marxianus CICC 33557, purchased from China Industrial Microbiological Culture Collection Center; (3) Saccharomyces cerevisiae JJ4, self-screened strain, with a deposit number of CCTCC NO: M 2018219, disclosed in Chinese patent CN108949595B; (4) Saccharomyces cerevisiae JP2, self-screened strain, with a deposit number of CCTCC NO: M 2010214, disclosed in Chinese patent CN102154135B.

[0085] 1.1.2 Raw materials: native grapes, specifically purple autumn thorn grapes, purchased from the market.

[0086] 1.1.3 Culture medium: MRS and malt extract culture medium are both finished products purchased from Haibo Biotechnology Co., Ltd.

[0087] 1.2 Methods

[0088] 1.2.1 Preparation process of native grape enzyme

[0089] (1) Preparation of bacterial strains

[0090] a) Preparation of yeast seed solution: CICC 33557, JJ4 and JP2 glycerol stocks were inoculated into malt wort liquid medium respectively, and cultured in a shaking incubator at 28°C and 150 r / min for 24-28 h; then 10% (v / v) was inoculated into fresh malt wort medium, and cultured in a shaking incubator at 28°C and 150 r / min for 24-28 h; centrifuged at 9000 r / min and 4°C for 10 min, washed once with phosphate buffer, and then suspended in an equal volume of sterile grape juice for later use.

[0091] b) Preparation of lactic acid bacteria seed liquid: RJS1401 glycerol-preserved seed was inoculated into MRS liquid medium and cultured at 35°C for 24 h; then 10% (v / v) was inoculated into fresh MRS liquid medium, cultured at 35°C for 15 h, centrifuged at 9000 r / min and 4°C for 10 min, washed once with phosphate buffer, and then suspended with an equal volume of sterile grape juice for later use.

[0092] (2) Substrate preparation and inoculation fermentation

[0093] Grapes are sorted, cleaned, destemmed, and crushed, and purified water of 3-3.5 times the weight of the grapes is added, and 30-35% white sugar (based on the total weight) is added, mixed evenly, and kept warm in a 65°C water bath for 30 minutes to prepare the fermentation medium, which is then cooled and set aside. The inoculation and fermentation process is as follows:

[0094] Single bacteria fermentation: RJS1401 seed liquid is inoculated into the fermentation matrix at a rate of 6% (v / m), sealed, and fermented at a controlled temperature of 35±2°C for 15 days, shaken once a day, and the fermented material is filtered, pasteurized, etc. to obtain the native grape enzyme product.

[0095] Composite fermentation: CICC 33557 or JJ4 or JP2 is inoculated at a rate of 6% (v / m) into the fermentation matrix, sealed, and fermented at a controlled temperature of 28-30°C and 100-120r / min for 3 days; then RJS1401 seed liquid is inoculated at a rate of 10% (v / m), sealed, and fermented at a controlled temperature of 35±2°C for 12 days; the fermented material is filtered, pasteurized, etc. to obtain a native grape enzyme product.

[0096] 1.2.2 Testing or evaluation methods

[0097] (1) pH value: measured using a pH meter;

[0098] (2) SOD activity: The total superoxide dismutase assay kit produced by Nanjing Jiancheng Bioengineering Institute was used;

[0099] (3) GABA content: Berthelot colorimetric method.

[0100] 2 Results and analysis

[0101] like Fig.10 As shown. Compared with the fermentation of single strain RJS1401, the fermentation of compound yeasts had less effect on GABA content, but had a significant enhancement effect on SOD activity, especially the SOD activity of the combination of RJS1401 and JJ4 was the highest, reaching 82.6U / mL, which was 1.51 times that of the single strain fermentation; in addition, the aroma of the combination of RJS1401 and JJ4 was richer. This shows that RJS1401 can be fermented with three yeast strains, and the yeast mainly plays a role in improving the antioxidant activity and aroma components, especially JJ4, which is significantly better than the other two yeast strains.

[0102] (II) Application of strain RJS1401 in modifying the off-flavor of noni fruit

[0103] 1 Materials and methods

[0104] 1.1 Materials

[0105] 1.1.1 Bacterial strains: (1) Lactobacillus breve RJS1401, with a preservation number of CCTCC NO: M20242296; (2) commercial brewer's yeast and fruit and vegetable enzyme fermentation culture (containing only lactic acid bacteria), both of which are commercially available.

[0106] 1.1.2 Culture medium: MRS, finished product, Beijing Luqiao Technology Co., Ltd.

[0107] 1.1.3 Raw materials: Noni fruit, commercially available.

[0108] 1.2 Methods

[0109] 1.2.1 Preparation of bacterial strains

[0110] The test strain RJS1401 glycerol stock was inoculated into MRS liquid medium and cultured at 35°C for 24 h. Then, 10% (v / v) was inoculated into fresh MRS liquid medium and cultured at 35°C for 15 h. Centrifugation was performed at 9000 r / min and 4°C for 10 min. The bacterial sludge was taken and washed twice with sterile phosphate buffer. The bacterial cells were then suspended with sterile phosphate buffer and the bacterial count was adjusted to 6.0×10 8 CFU / mL, for future use. 1.2.2 Raw material processing and inoculation fermentation

[0111] The noni fruit was sorted, washed, and crushed, and 3-3.5 times the mass of the fruit was added with purified water, 30-35% white sugar (by total weight), and mixed evenly to obtain a fermentation matrix. The commercial yeast agent was added to the fermentation matrix at a mass ratio of 0.1%, and canned at 2 / 3 of the canning volume, and fermented at 28-30°C and 100-120r / min for 3 days; then RJS1401 seed liquid was added at a 2% (v / m) inoculation amount, and the treatment of adding 0.1% fruit and vegetable enzyme fermentation agent was used as a control, and fermented at 35±2°C for 10-12 days; after the fermentation was completed, filtration, sterilization and other treatments were performed; the effects of the two treatments on the modification of the off-flavor of noni fruit were mainly evaluated.

[0112] 2 Results and analysis

[0113] The results showed that the flavors of the noni fruit enzyme samples obtained by the control treatment and the self-screened strain treatment were quite different; the control treatment had a distinct sour and rancid smell, which was caused by a large amount of volatile fatty acids (butyric acid, octanoic acid, etc.) in the noni fruit; the self-screened strain treatment had a very light sour and rancid smell of noni fruit, and exuded a pleasant fermentation aroma, which was accepted by most tasters. This shows that RJS1401 has a significant effect on modifying the off-flavor of noni fruit.

[0114] (III) Application of strain RJS1401 in the preparation of low-nitrite pickled vegetables

[0115] 1 Materials and methods

[0116] 1.1 Materials

[0117] 1.1.1 Bacterial strain: Lactobacillus breve RJS1401, with the deposit number of CCTCC NO: M 20242296. 1.1.2 Culture medium: MRS, finished product, Beijing Luqiao Technology Co., Ltd.

[0118] 1.1.3 Reagents: Nitrite assay kit, Nanjing Jiancheng Bioengineering Institute.

[0119] 1.1.4 Raw materials: Chinese cabbage and radish, commercially available.

[0120] 1.2 Methods

[0121] 1.2.1 Bacterial Activation

[0122] The test strain RJS1401 glycerol-preserved strain was inoculated into MRS liquid medium and cultured at 35°C for 24 hours. Then, 10% (v / v) was inoculated into fresh MRS liquid medium and cultured at 35°C for 15 hours for the second activation and standby use.

[0123] 1.2.2 Inoculation and fermentation

[0124] Wash and sterilize the glass jar for later use. Take fresh vegetables, wash and dry them, cut them into small pieces of 4×2cm in length×width or 4×3×2cm in length×width×height in a clean environment, put them into the glass jar, add the ingredients; then add 7% sterile saline in a ratio of 2:1 for salt water: vegetables; take the activated RJS1401 at a 10% (v / m, based on total weight) inoculation amount, centrifuge at 9000r / min and 4℃ for 10min, wash the bacteria twice with sterile saline, finally suspend the bacteria with sterile saline, add them to the kimchi jar, seal them, avoid light, and ferment them at 25℃ for 7d; take the treatment without inoculation as the control. After the fermentation, detect the nitrite content and evaluate the flavor.

[0125] 2 Results and analysis

[0126] This experiment studied the degradation effect of strain RJS1401 on nitrite produced in the process of pickling cabbage and radish; the control and inoculated treatment of the cabbage group were marked as B-CK and B-RJS1401, respectively, and the control and inoculated treatment of the radish group were marked as L-CK and L-RJS1401, respectively. Fig.11 . After 7 days of fermentation, the nitrite content of the cabbage treatment group (B-RJS1401) with strain RJS1401 added was 1.03 mg / kg, and that of the control group (B-CK) was 11.36 mg / kg, which was 11 times that of the treatment group. The nitrite content of the radish treatment group (L-RJS1401) with strain RJS1401 added was 1.24 mg / kg, and that of the control group (L-CK) was 17.77 mg / kg, which was more than 14 times that of the treatment group. It can be seen that RJS1401 can effectively degrade the nitrite produced in the preparation process of pickled vegetables, so that the nitrite of the prepared product is maintained at a low level, and the product is rich in layers and bright in color.

[0127] In summary, the short growth-promoting Lactobacillus RJS1401 of the present invention can effectively degrade organic phosphorus and nitrite, exhibit good stress resistance and γ-aminobutyric acid (GABA) production ability, and has a significant odor modification effect; the strain can effectively degrade the nitrite produced in the preparation process of pickled vegetables, so that the nitrite of the prepared product is maintained at a low level, and the product has rich layers and bright colors; the bacteria provide a new probiotic resource for the development of edible plant enzymes, pickled vegetables and other products.

[0128] Although the specific implementation modes of the present invention are described above, those skilled in the art should understand that the specific implementation modes described are only illustrative and are not intended to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A breve growth-promoting Lactobacillus, characterized in that: The brevis lactobacillus is Levilactobacillus brevis RJS1401, which was deposited in the China Center for Type Culture Collection in Wuhan on October 22, 2024, with a deposit number of CCTCC NO: M 20242296.

2. The Lactobacillus breve according to claim 1, characterized in that: The application of the breve growth-promoting Lactobacillus RJS1401 in edible plant enzymes.

3. A breve growth-promoting Lactobacillus according to claim 2, characterized in that: The application of the breve growth-promoting Lactobacillus RJS1401 in native grape enzyme.

4. The Lactobacillus breve according to claim 1, characterized in that: The application of the Lactobacillus breve RJS1401 in modifying the off-flavor of noni fruit.

5. The Lactobacillus breve according to claim 1, characterized in that: The application of the Lactobacillus breve RJS1401 in the processing of pickled vegetables.

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