Lactobacillus plantarum and application thereof

Abstract

The invention discloses lactobacillus plantarum and application thereof, and relates to the technical field of microorganisms, in particular to the technical field of lactobacillus plantarum and application thereof. The invention relates to a lactobacillus plantarum Zz-2025 and a preparation method of the lactobacillus plantarum Zz-2025. The preservation number of the lactobacillus plantarum Zz-2025 is CGMCC (China General Microbiological Culture Collection Center) N0.33707, and the preservation number of the lactobacillus plantarum Zz-2025 is CGMCC N0.33707. The strain produces exosomes, and experimental results speculate that the strain exosomes have bacteriostatic action and can effectively inhibit the growth of aerogenic bacteria. The fermented Chinese sauerkraut can greatly improve the crispness of the Chinese sauerkraut, can prolong the shelf life, and can be preserved for 6 months without bag expansion under vacuum packaging and normal temperature.

Description

Technical Field

[0001] The present invention relates to the technical field of microbiology, and specifically to the technical field of a Lactobacillus plantarum and its application. Background Art

[0002] Pickled Chinese cabbage can be an appetizer, a side dish to go with rice, or a seasoning for cooking dishes in the diet. It can be divided into Northeast pickled Chinese cabbage, Sichuan pickled Chinese cabbage, Guizhou pickled Chinese cabbage, Fuyuan pickled Chinese cabbage in Yunnan, German pickled Chinese cabbage, etc. The taste styles of pickled Chinese cabbage in different regions are also different.

[0003] Previously, there were no off-season greenhouse crops. People in Northeast China invented the method of pickling Chinese cabbage for winter storage in order to eat green vegetables in winter. The raw material of Northeast pickled Chinese cabbage is the Chinese cabbage that local people are used to. When pickling Chinese cabbage, first select good cabbages, then remove the remaining roots, rotten leaves, large leaves and yellow leaves, dry them in the sun for a few days, wash them with clean water, and then place them neatly in a large vat one by one and layer by layer. After pressing a big stone on the top of the vegetables, add raw water or cooled boiled water (preferably cooled boiled water) to soak and pickle them, seal and store them, and let the vegetables shrink and ferment slowly in a cold environment. After thirty days, it will be a great success. When the temperature drops, pickled Chinese cabbage needs to be taken out of the vat through the ice floes. This method is called raw pickling. There is also a cooked pickling method, which takes less time. First, boil a pot of boiling water, scald the washed Chinese cabbage in the pot, let it cool and then press it into the vat. After pickling for 30 days like this, it can be stewed and eaten. With the development of industrial fermentation technology, there are few people pickling Chinese cabbage at home now, and they all directly buy finished pickled Chinese cabbage products.

[0004] High-quality pickled Chinese cabbage smells of natural sourness and fermentation aroma, without peculiar smell; and tastes sour, crispy, fresh and tender, with a pure flavor, remaining sour after chewing several times; when pinched with hands, it should have a tough feeling. At present, industrial fermentation of pickled Chinese cabbage is achieved by adding fermentation starters. However, due to the limitation of the strains in the fermentation starters used, the pickled Chinese cabbage has poor crispness, short shelf life and is easy to bulge the bag. Summary of the Invention

[0005] In order to solve the problems of poor crispness, short shelf life and easy bag bulging of the existing pickled Chinese cabbage, the present invention provides a Lactobacillus plantarum and its application.

[0006] A Lactobacillus plantarum of the present invention, the strain is Lactobacillus plantarum Zz-2025; the preservation number of Lactobacillus plantarum Zz-2025 is CGMCC NO.33707.

[0007] Application of the above strain of the present invention in pickled Chinese cabbage fermentation, using Lactobacillus plantarum Zz-2025 as a fermentation strain to be mixed and fermented with water and shredded Chinese cabbage for pickling.

[0008] Furthermore, Chinese cabbage shreds, water and the bacterial liquid of Lactobacillus plantarum Zz-2025 are mixed in a ratio of 500 g: 400 g: 25-30 mL; wherein the OD value of the bacterial liquid of Lactobacillus plantarum Zz-2025 = 1±0.05.

[0009] Furthermore, 25 g of salt is added to every 500 g of Chinese cabbage shreds for fermentation and pickling.

[0010] Lactobacillus plantarum Zz-2025 of the present invention has a moderate acid-producing property. After 7 days of fermentation and pickling, the pH value of the fermentation supernatant is 4.22. Using Lactobacillus plantarum Zz-2025 to ferment pickled Chinese cabbage can greatly improve the crispness of pickled Chinese cabbage and can extend the shelf life. It can be stored at room temperature in vacuum packaging for 6 months without bag swelling.

[0011] Lactobacillus plantarum Zz-2025 of the present invention produces exosomes. It is speculated from the experimental results that the exosomes of this strain have antibacterial effects and can effectively inhibit the growth of gas-producing bacteria.

[0012] Lactobacillus plantarum Zz-2025 belongs to Lactobacillus plantarum and the genus Lactobacillus. It is preserved in the China General Microbiological Culture Collection Center. The preservation address is No. 3, Building 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences. The preservation number is CGMCC NO. 33707, and the taxonomic name is Lactobacillus plantarum. Description of the Drawings

[0013] Figure 1 It is an observation diagram of Gram staining of Lactobacillus plantarum Zz-2025;

[0014] Figure 2 It is a phylogenetic tree constructed by homologous alignment of the 16S RNA sequences of Lactobacillus plantarum Zz-2025 (experimental number S1) and related strains;

[0015] Figure 3It is a comparison chart before and after the biochemical identification reaction of Lactobacillus plantarum Zz-2025;

[0016] Figure 4 It is a column chart of the crispness detection of the fermented sauerkraut samples in each group after seven days of sealed fermentation and pickling in Example 1. Detailed implementation manners

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0018] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0019] Detailed implementation manner 1: In this implementation manner, there is a strain of Lactobacillus plantarum, and this strain is Lactobacillus plantarum Zz-2025; the preservation number of Lactobacillus plantarum Zz-2025 is CGMCC NO. 33707.

[0020] The Lactobacillus plantarum Zz-2025 in this implementation manner was isolated and purified from the sauerkraut fermentation broth in Suihua City (location) in August 2024.

[0021] ① The separation method adopts the gradient dilution method.

[0022] ② Purification method: Repeatedly streak culture until it is confirmed that the colony morphology and size in the same plate are the same, and the purified single strain Zz-2025 (experimental number S1) is obtained.

[0023] ③ Gram staining: Pick a single colony for Gram staining and microscopic examination (as Figure 1 shown) to identify the type of bacteria.

[0024] ④ 16s sequencing identification. The nucleotide sequence alignment (NCBI database) of the 16S RNA of this strain has a very high homology with Lactobacillus plantarum of the genus Lactobacillus, and the homology is 99.93%; the phylogenetic tree constructed by Lactobacillus plantarum Zz-2025 and related strains based on the 16S RNA sequence is asFigure 2 as shown. Combined with the Gram staining of this strain (such as Figure 1 as shown) and the microscopy results, it was identified as Lactobacillus plantarum and named Lactobacillus plantarum Zz-2025.

[0025] The biochemical identification results of Lactobacillus plantarum Zz-2025 are shown in Table 1 and Figure 3 as shown; except for the raffinose reaction being negative, the rest are all positive.

[0026] Table 1

[0027] Product Color Result Judgment Esculin Black Positive Cellobiose Yellow Positive Maltose Yellow Positive Mannitol Yellow Positive Salicin Yellow Positive Sorbitol Yellow Positive Sucrose Yellow Positive Raffinose Purple-Grey Negative Inulin Yellow Positive Lactose Yellow Positive

[0028] Experimental results have shown that Lactobacillus plantarum Zz-2025 and its fermentation broth are non-toxic and harmless to humans, animals and the environment.

[0029] Example 1

[0030] Pickled Chinese sauerkraut: Chinese cabbage shreds, water and the fermentation strain broth were mixed and pickled at a ratio of 500 g: 400 g: 25 - 30 mL, and salt was added at a ratio of 25 g of salt per 500 g of Chinese cabbage shreds for pickling; among which the OD value of the fermentation strain broth = 1.

[0031] The tests were grouped as follows:

[0032] Group 1 was natural fermentation;

[0033] The fermentation strain in Group 2 was LGG probiotic (Lactobacillus rhamnosus GG);

[0034] The fermentation strain in Group 3 was Lactobacillus plantarum Zz-2025 (experimental number S1);

[0035] The fermentation strain in Group 4 was commercially available lactic acid bacteria for pickling Chinese sauerkraut;

[0036] The fermentation strain in Group 5 was lactic acid bacteria isolated from the same batch as Lactobacillus plantarum Zz-2025 (experimental number milk 2) milk 2;

[0037] The fermentation strain in Group 6 was lactic acid bacteria isolated from the same batch as Lactobacillus plantarum Zz-2025 (experimental number milk 3) milk 3.

[0038] Seal and ferment for seven days, and then use a texture analyzer to detect the crispness (maximum shear force g) of each group of pickled Chinese cabbages and detect the pH value of the fermentation broth; the results are shown in Table 2 and Figure 4 as follows.

[0039] Group 1 2 3 4 5 6 Maximum Shearing Force g 510.65 472.40 537.63 424.79 414.06 477.01 PH Value 4.18 4.20 4.22 4.22 4.42 4.14

[0040] After 7 days of fermentation and pickling in the jar, vacuum plastic packaging is carried out immediately, and the swelling of the bags is detected during storage at room temperature. The samples in Group 1 have the shortest storage time at room temperature, and the samples all show bag swelling in less than 1 month. The samples in Group 2, Group 4, and Group 5 have a storage time at room temperature not exceeding 2.5 months, and the samples in Group 6 have a slightly longer storage time at room temperature but still do not exceed 3 months. However, the samples in Group 3 can be stored at room temperature for 5.5 - 6 months.

[0041] The Lactobacillus plantarum Zz-2025 of the present invention can ferment pickled Chinese cabbages in a short time. It is speculated that this strain has an antibacterial effect and can effectively inhibit the growth of gas-producing bacteria; therefore, it can greatly extend the shelf life, and can also significantly improve the crispness of pickled Chinese cabbages and enhance the taste.

Claims

1. A strain of Lactobacillus plantarum, characterized in that The strain is Lactobacillus plantarum Zz-2025; the preservation number of Lactobacillus plantarum Zz-2025 is CGMCC NO.33707.

2. The use of the strain according to claim 1 in sauerkraut fermentation, characterized in that: Lactobacillus plantarum Zz-2025 was used as the fermentation strain and mixed with water and shredded Chinese cabbage for fermentation and pickling.

3. The use according to claim 2, characterized in that: The shredded Chinese cabbage, water and Lactobacillus plantarum Zz-2025 bacterial solution are mixed in a ratio of 500 g:400 g:25-30 mL; wherein the OD value of the Lactobacillus plantarum Zz-2025 bacterial solution is 1±0.

05.

4. The use according to claim 2 or 3, characterized in that: Add 25g of salt for every 500g of shredded cabbage and ferment and pickle.

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