CN114921377B

CN114921377B - Weissella greece, screening method and application thereof

Info

Publication number: CN114921377B
Application number: CN202210616743.6A
Authority: CN
Inventors: 王斌; 苟中军; 邹滢; 杜江; 黄巧; 杨光; 肖�琳
Original assignee: Juhui Food Technology Chongqing Co ltd
Current assignee: Juhui Food Technology Chongqing Co ltd
Priority date: 2022-06-01
Filing date: 2022-06-01
Publication date: 2023-05-30
Anticipated expiration: 2042-06-01
Also published as: CN114921377A

Abstract

The invention provides Greenwort bacteria, a screening method and application thereof, wherein the Greenwort bacteria are Greenwort bacteria (Weissella hellenicai) L-1 strains which are screened from pickled pickle, and the Greenwort bacteria (Weissella hellenicai) L-1 strains are used for preparing purple sweet potato fermentation products, kelp fermentation products and other vegetable fermentation products. The Weissella greece L-1 provided by the invention can be used for high-yield lactic acid, and can resist 50g/L NaCl and an acidic environment with pH=2 at the highest, the strain can effectively utilize inherent ingredients of food, and the total acid content in a fermentation product is improved, so that the product has rich acid flavor and huge color and luster, and the requirements of consumers on fermented foods are met.

Description

Weissella greece, screening method and application thereof

Technical Field

The invention belongs to the technical field of microorganisms, and particularly relates to Weissella greece, a screening method and application thereof.

Background

The southwest area has the tradition of edible fermented food, contains abundant probiotics resources, but the current probiotics resources in the southwest area have unclear bottoms, and the excavation and basic characteristic research is insufficient, so that the method has become a bottleneck for restricting the development of the fermented food industry in the southwest area. The flavor of the fermented food is an important factor affecting the sensory quality and consumer acceptance of the product, the pleasant flavor of traditional pickle in southwest area is obtained by fermentation of heterolactic acid bacteria and fermentation of homolactic acid bacteria, the heterolactic acid bacteria rapidly produce a large amount of flavor substances such as acetic acid, ethanol, mannitol and the like in the initial stage of fermentation, and the homolactic acid bacteria replace the heterolactic acid bacteria to produce a large amount of acid along with the fermentation, so that the final product has very sour and refreshing feeling, and the heterolactic acid bacteria and homolactic acid bacteria cooperatively ferment to form the unique flavor. The fermentation bacteria in traditional pickle in southwest area are researched and used for rapid fermentation in fermented food, and the method has wide application prospect in deep research on flavor characteristics, tolerance and the like in the fermented food to obtain high-quality products.

Purple sweet potato (Ipomoea batatas l.) is an edible root belonging to the family of the bouilloceae. The dark purple sweet potato is due to the presence of highly acylated anthocyanin taking anthocyanin or paeoniflorin as aglycone, which is a natural pigment which is very beneficial to health. It is reported that a large amount of anthocyanin and phenols in purple sweet potato have physiological activities of antioxidation, anticancer, anti-inflammation, antihyperglycemic and the like. In addition, the purple sweet potato also contains 18% of purple sweet potato starch, about 5% of sugar, about 2% of protein, dietary fibers, vitamins (C, B, B2 and E), mineral substances (potassium, calcium, magnesium, zinc) and other nutritional ingredients, and iodine and selenium are more than 20 times of those of common sweet potatoes. Therefore, the purple sweet potato is a good name for life-prolonging food, and is a green and healthy food raw material. However, in the prior art, the purple sweet potato has the problems of easy color change, easy taste change, poor taste and the like in the processing process.

Kelp is rich in chemical components and bioactive substances and has been used in many industrial fields such as foods, feeds, and prodrugs. Researches show that the kelp contains abundant fucoidin which is divided into 3 substances of algin, brown algae starch and fucoidin, wherein the algin accounts for 15% -25%, and the kelp has high application value in the reprocessing process of functional foods and partial medicines. In addition, kelp also contains abundant alginic acid, vitamins, minerals and various trace elements, and has very rich delicate flavor due to the free glutamic acid. At present, the cultivation technology of kelp in China is mature, but the kelp processing and utilization are still in the primary stage, and the product mainly comprises salted kelp, light dry kelp and instant seasoned kelp, innovatively develops the kelp deep processing industry, develops healthy and nutritional kelp processing products, meets the requirements of 2030 healthy Chinese strategy in China, can increase the added value of kelp, and promotes the sustainable development of kelp industry chains.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides the Greek Weissella, the screening method and the application thereof, the Greek Weissella is quick in acidogenesis and high in lactic acid production, and the Greek Weissella obtained by screening is applied to fermented foods, so that the fermented foods have the characteristics of soft acidity, full flavor, good color and the like.

The invention solves the technical problems by adopting the following technical scheme:

the first object of the present invention is to provide a greek Weissella, wherein the greek Weissella is Greek Weissella (Weissella hellenicai) L-1, which is preserved in China center for type culture Collection, and has an address of Wuhan, hubei province, wuchang and Lujia mountain, a preservation number of CCTCC M2022425, and a preservation time of 2022, 4 months and 19 days.

Further, the 16S rDNA sequence of the Weissella Greek (Weissella hellenicai) L-1 is shown in SEQ ID NO. 3.

The second object of the invention is to provide a screening method of Weissella greece, which is characterized by comprising the following steps:

s1, weighing a pickled Chinese cabbage sample in southwest area, putting the pickled Chinese cabbage sample into a test tube containing sterile deionized water, and fully oscillating to form a mother suspension; preparing the mother suspension to 10 ^-1 、10 ^-2 、10 ^-3 、10 ^-4 、10 ^-5 Gradient dilution of deionized water for standby; respectively coating the gradient dilutions on MRS solid culture medium, culturing at 35deg.C for 48 hr, and separating and purifying to obtain fractionsIsolating the strain;

s2, inoculating the separated strain obtained in the S1 into an MRS liquid culture medium, and culturing at 35 ℃ and 80rpm for 18 hours to obtain seed liquid;

s3, inoculating the seed solution obtained in the S2 into an MRS liquid culture medium according to an inoculum size of 1%, and culturing at 35 ℃ and 80rpm for 24 hours to obtain the Weissella greece (Weissella hellenicai) L-1 strain.

Furthermore, the Weissella greece (Weissella hellenicai) L-1 strain can tolerate an acidic environment with the pH=2 and the concentration of 50g/L NaCl, so that the strain can effectively colonize in pickled vegetables to start vegetable fermentation, realize rapid acid production, improve acid production rate and rapidly start vegetable fermentation, and a vegetable fermentation product is obtained.

The third object of the invention is to provide an application of the Weissella greece (Weissella hellenicai) L-1 strain in vegetable fermentation products.

Further, the vegetable fermentation products include purple sweet potato fermentation products and kelp fermentation products.

Further, the purple sweet potato fermentation product is purple sweet potato fermentation sauce.

Further, the kelp fermentation product is kelp vegetable juice.

The fourth object of the invention is to provide a purple sweet potato fermentation product with the Weissella greece (Weissella hellenicai) L-1 strain as a starter, which is characterized in that the preparation method comprises the following steps:

activating the Weissella gracilis L-1 strain to obtain an activated strain; cleaning fresh purple sweet potatoes, steaming the fresh purple sweet potatoes with water according to a volume ratio of 1:1, pulping the fresh purple sweet potatoes at a fixed volume, filling the steamed purple sweet potatoes into a sterilized triangular flask, inoculating the activated strain of the Weissella greek strain L-1 according to an inoculum size of 5% of the volume mass ratio, and standing and fermenting the purple sweet potatoes at 20-25 ℃ for 7 days to obtain the purple sweet potato fermentation product.

Preferably, the fermentation temperature of the purple sweet potato is 21 ℃.

Further, the activation process is as follows: inoculating Weissella gracilis L-1 strain on MRS solid culture medium, activating and culturing at 35deg.C for 24 hr, inoculating toothpick-derived thallus on 250mL triangle containing 100mL MRS liquid culture mediumShake culturing at 35deg.C for 18 hr at 80r/min until bacterial liquid concentration reaches 10 ⁸ CFU/mL。

The fifth object of the present invention is to provide a kelp fermentation product using the strain of Weissella greece (Weissella hellenicai) L-1 as a starter, which is characterized in that the preparation method comprises the following steps:

activating the Weissella gracilis L-1 strain to obtain an activated strain; cleaning the selected kelp and vegetables, pulping the kelp and water in a ratio of 1:3, and pulping the vegetables and water in a ratio of 1:2; and (3) filling the pulped kelp liquid and vegetable liquid into a sterilized triangular flask, inoculating the activated strain of the Weissella Greek strain L-1 according to the inoculum size of 2% by volume and mass, and standing and fermenting for 6 days at 20-25 ℃ to obtain the kelp fermentation product.

Preferably, the kelp fermentation temperature is 21 ℃.

Further, the volume ratio of the kelp liquid to the vegetable liquid after beating, which is mixed before inoculation, is 1:3.

Further, the vegetable is cabbage.

Compared with the prior art, the invention has the beneficial technical effects that:

the Weissella greece (Weissella hellenicai) L-1 strain provided by the invention has remarkable lactic acid production capability, and can endow a product with unique and soft acid flavor. The strain can endure an acidic environment with the pH value of 2 and the concentration of 50g/L NaCl, has high acid production rate and can quickly start vegetable fermentation. The purple sweet potato fermented sauce prepared by fermentation has comprehensive nutrition, thick taste and high added value, does not change the original color system of the purple sweet potato, and releases small molecular substances which are more beneficial to digestion and absorption of human bodies. The natural ingredients in the kelp and the cabbage are fully utilized to generate organic acid, so that the product has the special acid flavor of lactobacillus fermentation, and the flavor is full and soft. The preparation process of the vegetable fermentation product is simple, is favorable for large-scale industrialization, does not add any essence, pigment or preservative, and is a safe food of lactobacillus fermented vegetables.

The pickled Chinese cabbage selected in the invention is a pickled Chinese cabbage of a common farmer in southwest area, a commercially available pickled Chinese cabbage in southwest area, and the like.

The foregoing description is only an overview of the present invention, and is intended to be implemented in accordance with the teachings of the present invention in order that the same may be more clearly understood and to make the same and other objects, features and advantages of the present invention more readily apparent.

Drawings

FIG. 1 shows colony morphology of Weissella Greek (Weissella hellenicai) L-1 strain on MRS solid medium in the present invention.

FIG. 2 is a microscopic image of the L-1 strain of Weissella Greek (Weissella hellenicai) in accordance with the present invention.

FIG. 3 shows the salt concentration tolerance of the L-1 strain of Weissella Greek (Weissella hellenicai) according to the present invention.

FIG. 4 is an acidic pH tolerance diagram of the L-1 strain of Weissella Greek (Weissella hellenicai) according to the present invention.

FIG. 5 is a graph showing the acid production rate of the L-1 strain of Weissella Greek (Weissella hellenicai) according to the present invention.

Detailed Description

The technical scheme of the invention is further described in detail below with reference to the attached drawings and specific embodiments. It is to be understood that the following examples are illustrative only and are not to be construed as limiting the scope of the invention. All techniques implemented based on the above description of the invention are intended to be included within the scope of the invention.

In addition, unless otherwise specifically indicated, the various raw materials, reagents, instruments and equipment used in the present invention may be obtained commercially or prepared by existing methods. The quantitative experiments in each embodiment of the invention are all set with three repeated experiments, and the results are averaged.

The modified MRS solid culture medium used in the embodiment of the invention comprises 10g of peptone, 5g of yeast extract, 10g of beef extract, 20g of glucose, 2g of dipotassium hydrogen phosphate, 2g of triammonium citrate, 5g of sodium acetate, 80 ml of tween, 0.58g of magnesium sulfate heptahydrate, 0.25g of manganese sulfate tetrahydrate, 20g of agar, 10g of calcium carbonate, 0.1g of bromocresol purple, 1000ml of deionized water and pH of 6.2-6.4.

Example 1: isolation, screening and identification of Weissella Greek L-1 strains

1.1 isolation of Weissella Greek L-1 Strain

The separation of the Weissella greece L-1 strain comprises three steps of sampling, enrichment and preliminary screening, and re-screening, and the method specifically comprises the following steps:

1. sampling

The pickled Chinese cabbage samples are collected from peasants in southwest areas by using an ice box, are put into clean sampling bags, marked and are transported back to a laboratory to be stored in a refrigerator at 4 ℃ to be used as samples.

2. Enrichment and preliminary screening

In a sterile ultra-clean workbench, 1.0g of a homemade pickled Chinese cabbage sample is weighed, placed in a test tube containing 9mL of sterile deionized water, and fully oscillated by vortex to prepare a mother suspension. The mother suspension was then prepared to 10 using deionized water ^-1 、10 ^-2 、10 ^-3 、10 ^-4 、10 ^-5 And (3) deionized water gradient dilutions, wherein 100 mu L of each gradient dilution is respectively coated on an improved MRS solid agar culture medium, cultured for 48 hours at 35 ℃, and strains with different forms and calcium dissolving rings are streaked and purified to obtain isolated strains, and the isolated strains are stored in a refrigerator at-80 ℃ for later use by using 50% glycerol.

3. Double screen

The separated strain obtained by primary screening is inoculated into MRS liquid culture medium, cultured for 18 hours at 35 ℃ and 80rpm, seed liquid is prepared, inoculated into a triangular flask with the volume of 250mL containing 100mL of MRS liquid culture medium according to the inoculum size of 1 percent, cultured for 24 hours at 35 ℃ and 80rpm, the strain is obtained, the strain is named as strain L-1, strain M-2, strain M-6, strain L-3 and strain L-7 in sequence, the lactic acid content of the strain obtained by separation in all pickled Chinese cabbage samples is measured, and experimental results are shown in table 1, so that the lactic acid producing capacity of the strain L-1 is higher than that of other samples.

TABLE 1 lactic acid yield comparison

1.2 identification of strains

Performing a series of physiological and biochemical identification on the pure culture of the strain L-1 obtained by separation and purification, extracting DNA, amplifying and sequencing 16S rDNA, amplifying the 16S rDNA by using primers F27 and R1492,

the primer sequences were as follows:

f27:5'-AGAGTTGATCATGGCAG-3', as shown in SEQ ID NO. 1;

r1492:5'-TAGGGTTACCTTGTTACGCTT-3' as shown in SEQ ID NO.2

The PCR amplification conditions were 95℃for 5min,94℃for 30s, 55℃for 30s, 72℃for 90s, 30 cycles, 72℃for 10min and 4℃for storage.

Sequencing the PCR amplified product, wherein the sequencing result is shown as SEQ ID NO. 3.

The strain L-1 is named as Greenwich bacteria (Weissella hellenicai) L-1 by homology comparison and combination of morphological and physiological biochemical characteristics of the strain L-1. The isolated and screened Weissella gracilis L-1 strain of the embodiment is cultured on an MRS solid medium, colony morphology is observed, microscopic image observation is carried out on the strain, and the observation results are shown in the accompanying

drawings

1 and 2. Referring to FIG. 1, it can be seen that the Weissella greece L-1 strain of the present invention forms white round, regular-edged, smooth-surfaced opaque colonies on MRS solid medium.

Referring to FIG. 2, the Wessezia Greek L-1 strain was observed under a microscope and microscopic examination revealed as irregular short rods, paired or short-chain arrangement bacteria.

Meanwhile, physiological and biochemical characteristics of the Weissella greece L-1 strain are tested, as shown in Table 2:

TABLE 2 physiological and biochemical characteristics of Weissella Greek L-1 Strain

Note that: "+" indicates positive reaction, present or present, "-" indicates negative reaction, absent or not present.

The Greek Weissella obtained by the method is Greek Weissella (Weissella hellenicai) L-1, and is preserved in China center for type culture Collection, with the address of Wuhan, wuchang and Lopa nationality, hubei province, china, and the preservation number of CCTCC M2022425, and the preservation time of 2022, 4, and 19 days.

It can be seen that the screening method of the Greek Weissella (Weissella hellenicai) L-1 strain from typical farmhouse pickle in southwest area in this example adopts a gradient concentration dilution method, the diluted sample liquid is coated on an improved solid MRS plate, anaerobic culture is carried out for 48 hours at 35 ℃, strains with different colonies and calcium-dissolving rings are selected, further streaking, separation and purification are carried out, the separated strains are obtained, then the L-1 strain is determined by combining with lactic acid production capability experiment, and the strain species is determined by sequence comparison. The L-1 strain has strong lactic acid production capacity, and the concentration of the lactic acid can reach 10.46mg/L.

Example 2: salt tolerance, acid resistance and acid production ability of Wessezia Greek (Weissella hellenicai) strain L-1 the salt tolerance of Wessezia Greek strain L-1 was tested:

after the Weissella gracilis strain L-1 is activated in MRS liquid culture medium for 12 hours, the OD600 value of the bacterial liquid reaches 0.8. The culture was inoculated in a 250 mL-volume Erlenmeyer flask containing 100mL of MRS liquid medium having different NaCl mass concentrations (0, 10, 20, 30, 40, 50, 60 g/L) at an inoculum size of 1%, 3 replicates were used for each group with seed medium without inoculation as a blank, and after shaking culture at 35℃for 48 hours at 80r/min, the absorbance of the culture was measured at 600nm using a spectrophotometer.

As shown in FIG. 3, the Greek Weissella strain L-1 has a relatively wide salt tolerance, and can tolerate 50g/LNaCl at the highest, and the result shows that the Greek Weissella strain L-1 has a relatively high salt tolerance.

Acid resistance of Wessezia Greek strain L-1:

after the Weissella gracilis strain L-1 is activated in MRS liquid culture medium for 12 hours, the OD600 value of the bacterial liquid reaches 0.8. The culture was inoculated into 250 mL-volume flasks containing 100mL of seed medium at different pH concentrations (1, 2, 3, 4, 5, 6, 7) at an inoculum size of 1%, 3 replicates were set for each group with the seed medium without inoculation as a blank, and after culturing at 35℃for 48 hours at 80r/min, the OD of the culture at 600nm was determined.

As shown in FIG. 4, the tolerance range of the acid pH of the strain L-1 was 2 to 7, and the acid pH of 2 was the highest, indicating that the strain L-1 had good adaptability to a wide range of acid conditions.

Acid-producing ability of Weissella Greek strain L-1:

a loop of Wissella gracilis strain L-1 colony is picked by a sterile inoculating loop, inoculated into MRS liquid culture medium and activated for 12 hours, and the OD600 value of the bacterial liquid reaches 0.8. Inoculating into 250mL triangular flask containing 100mL MRS liquid culture medium according to 1% inoculum size, shake culturing at 35deg.C at 80r/min for 24 hr with non-inoculated MRS liquid culture medium as blank control, taking samples every 3 hr, detecting pH value of the culture solution with pH meter, and calculating acid production rate of strain, wherein the acid production rate=culture medium initial pH-pH at each time point.

As shown in FIG. 5, the acid production capacity of the Wessezia graciliata strain L-1 is continuously enhanced along with the increase of the fermentation time, the pH of the fermentation liquor reaches 4.40 and the acid production rate reaches 1.99 when the fermentation time is 9 hours, the acid production rate of most lactic acid bacteria after 9 hours of culture is reported to be 0.43-1.29 in literature, the Wessezia graciliata strain L-1 screened in the experiment is obviously higher than the acid production rate of the Wessezia graciliata strain L-1 in 1.99, and the acid production rate of the Wessezia graciliata strain L-1 is very high, so that the characteristic plays an important role in subsequent fermentation.

Example 3 preparation of purple sweet potato paste by using Weissella Greek (Weissella hellenicai) L-1 Strain as a starter

S1, inoculating Weissella gracilis L-1 strain on MRS solid culture medium, activating and culturing at 35deg.C for 24 hr, inoculating thallus with toothpick into 250mL triangular flask containing 100mL MRS liquid culture medium, shake culturing at 35deg.C at 80r/min for 18 hr until bacterial liquid concentration reaches 10 ⁸ CFU/mL, the activated strain of the Weissella greek L-1 strain is obtained for standby;

s2, cleaning fresh purple sweet potatoes, steaming the fresh purple sweet potatoes with water at a ratio of 1:1, pulping the fresh purple sweet potatoes at a constant volume, filling the steamed purple sweet potatoes into a sterilized triangular flask, inoculating an activated strain of the Weissella greesi strain L-1 with an inoculum size of 5% in volume-mass ratio, and standing and fermenting the purple sweet potatoes at 20-25 ℃ (preferably 21 ℃) for 7 days to obtain the purple sweet potato fermented sauce.

Sample test 1: the total acid content in the purple sweet potato fermented paste is determined by NaoH titration method with reference to Ning Zhengxiang, and the results are shown as table 3, wherein the total acid content of the purple sweet potato paste fermented by the Weissella greece (Weissella hellenicai) L-1 strain is 0.66%.

TABLE 3 analysis of Total acids in fermented purple sweet Potato paste by Weissella Greek L-1 Strain

Sample test 2: 1g of the fermented sample was weighed and dissolved in 9mL of 80% ethanol. Sucking 0.5mL of the sample to be detected by a pipette, placing the sample into a 10mL colorimetric tube with a plug, adding 0.5mL of deionized water, shaking uniformly, adding 0.5mL of furin reagent, mixing uniformly, and adding 1.5mL of 20% Na after 1min ₂ CO ₃ The solution is evenly mixed, deionized water is used for constant volume to 10mL, the solution is placed in a constant temperature water bath kettle at 70 ℃ for heating for 10min, and after cooling, the OD value is measured in an ultraviolet spectrophotometer at 765 nm. Comparison was performed with gallic acid as standard, and the test results are shown in table 4. The result shows that the total phenol content of the purple sweet potato paste fermented by the Weissella Greek strain L-1 is 14.37mg gallic acid/g purple sweet potato paste weight, which is 5 times that of unfermented purple sweet potatoes.

TABLE 4 analysis of Total phenols in Weissella Greek L-1 fermented purple sweet potato paste

Sample test 3: and measuring the color of the fermented purple sweet potatoes by using a rovider colorimeter, wherein the length of a cuvette is 10mm. The result shows that the color of the purple sweet potato paste fermented by the Weissella Greek strain L-1 is red-yellow, the color system of the purple sweet potato cannot be changed, and the color of the purple sweet potato paste is basically similar to that of a control group.

TABLE 5 color detection values of Weissella Greek L-1 fermented purple sweet potato paste

In conclusion, the purple sweet potato fermented sauce prepared by the method of the embodiment has proper acidity and comprehensive nutrition. The Weissella greek L-1 strain can fully utilize the inherent components of the purple sweet potato raw material to generate organic acid, so that the product has the special acid flavor of lactobacillus fermentation, the flavor is full and soft, and the original color system of the purple sweet potato is not changed after the Weissella greek L-1 strain ferments the purple sweet potato sauce, which indicates that the processing mode does not damage the nutritional components such as purple sweet potato anthocyanin. Moreover, the total phenol content in the fermented paste of the purple sweet potato is increased, which indicates that the Weissella Greek L-1 can generate insoluble substances which are generated by a specific enzyme system and are used for breaking the esterification of phenolic acid in the purple sweet potato with carboxyl groups on a phenol ring or carboxyl groups on a molecular structure, and release the phenolic acid. The purple sweet potato fermented sauce prepared by fermentation has comprehensive nutrition, thick taste and high added value, and released micromolecular substances are more beneficial to digestion and absorption of human bodies.

EXAMPLE 4 preparation of kelp vegetable juice Using Weissella Greek (Weissella hellenicai) L-1 Strain as a starter

S1, inoculating Weissella gracilis L-1 strain on MRS solid culture medium, activating and culturing at 35 ℃ for 24 hours, inoculating bacterial cells into 250mL triangular flask containing 100mL MRS liquid culture medium by using toothpick, shake culturing at 35 ℃ for 18 hours at 80r/min until bacterial liquid concentration reaches 10 ⁸ CFU/mL, the activated strain of the Weissella greek L-1 strain is obtained for standby;

s2, removing samples with disease spots and rotting spots from the kelp and the cabbage, cleaning the kelp and the cabbage with tap water, pulping the kelp and the water according to the ratio of 1:3, and pulping the cabbage and the water according to the ratio of 1:2 for later use.

S3, filling the beaten kelp liquid and cabbage liquid obtained in the step S2 into a sterilized triangular flask according to the proportion of 1:3, inoculating an activated strain of the Weissella greece L-1 strain according to the inoculum size with the volume mass ratio of 2%, and standing and fermenting for 6 days at 20-25 ℃ (preferably 21 ℃) to obtain a kelp vegetable juice fermentation product.

Sample test 1: the total number of colonies was measured by referring to GB 4789.2-2016, and the pH was measured by a pH meter. Referring to Table 6, the results show that the total colony count in the kelp vegetable juice after the Greek Weissella L-1 is fermented for 6 days is increased to 7.38 (lg (CFU/mL)), which shows that the Greek Weissella L-1 can well metabolize organic matters in kelp cabbage and has stronger growth capacity; the pH value of the kelp vegetable juice after the fermentation of the Weissella Greek L-1 for 6 days is reduced from 6.78 to 3.67, which shows that the Weissella Greek L-1 can grow by utilizing the nutrient substances in the kelp cabbage liquid and simultaneously generate acid metabolic substances, so that the pH value of the environment is continuously reduced along with the fermentation.

TABLE 6 analysis of total colony count and pH in kelp vegetable juice fermented with Weissella Greek L-1

Sample test 2: the kelp vegetable juice sample after the Weissella greece L-1 is fermented for 6 days is centrifuged for 15min at 8000r/min, the supernatant is sucked, the total sugar content is measured by a phenol-sulfuric acid method, and the reducing sugar content is measured by a DNS method. Referring to Table 7, the results show that the total sugar content in the kelp vegetable juice after the Greek Weissella L-1 is fermented for 6 days is reduced from 40.49mg/mL to 33.79mg/mL, and the reducing sugar content is reduced from 16.69mg/mL to 14.46mg/mL, so that the Greek Weissella L-1 can be well colonized in the kelp vegetable juice, and the kelp and cabbage are fermented and utilized as a ready-made carbon source.

TABLE 7 analysis of total sugar and reducing sugar in kelp vegetable juice fermented by Weissella Greek L-1

In conclusion, the kelp vegetable juice prepared by the method of the embodiment is proper in sweetness and sourness. The Weissella greece L-1 strain can fully utilize the inherent components in kelp and cabbage to generate organic acid, so that the product has the special acid flavor of lactobacillus fermentation, and the flavor is full and soft.

The foregoing embodiment numbers of the present invention are merely for the purpose of description, and do not represent the advantages or disadvantages of the embodiments.

The embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and many forms may be made by those having ordinary skill in the art without departing from the spirit of the present invention and the scope of the claims, which are to be protected by the present invention.

Claims

1. A weissella greek, characterized by: the Weissella greece is Weissella greece (Weissella hellenicai) L-1, and is preserved in China Center for Type Culture Collection (CCTCC) M2022425.

2. A wegener greek according to claim 1, characterised in that: the 16S rDNA sequence of the Weissella Greek (Weissella hellenicai) L-1 is shown in SEQ ID NO. 3.

3. Use of a strain of westernum greek (Weissella hellenicai) L-1 according to any one of claims 1 or 2 for the preparation of a vegetable fermentation product.

4. A use according to claim 3, wherein: the vegetable fermentation products comprise purple sweet potato fermentation products and kelp fermentation products.

5. A preparation method of a purple sweet potato fermentation product by taking a Weissella Greek (Weissella hellenicai) L-1 strain as a starter is characterized by comprising the following steps:

activating the Weissella greek L-1 strain of claim 1 to obtain an activated strain; cleaning fresh purple sweet potatoes, steaming the fresh purple sweet potatoes with water according to a volume ratio of 1:1, pulping the fresh purple sweet potatoes at a fixed volume, filling the steamed purple sweet potatoes into a sterilized triangular flask, inoculating the activated strain of the Weissella greek strain L-1 according to an inoculum size of 5% of the volume mass ratio, and standing and fermenting the obtained product for 7 days at a temperature of 20-25 ℃ to obtain the purple sweet potato fermentation product.

6. The method of claim 5, wherein the activating comprises: inoculating Weissella gracilis L-1 strain on MRS solid culture medium, activating and culturing at 35 deg.C for 24 hr, inoculating thallus with toothpick into 250mL triangular flask containing 100mL MRS liquid culture medium, shake culturing at 35 deg.C constant temperature at 80r/min for 18h until bacterial liquid concentration reaches 10 ⁸ CFU/mL。

7. A preparation method of a kelp fermentation product by taking a Weissella greece (Weissella hellenicai) L-1 strain as a starter is characterized by comprising the following steps:

activating the Weissella greek L-1 strain of claim 1 to obtain an activated strain; cleaning the selected kelp and vegetables, pulping the kelp and water in a ratio of 1:3, and pulping the vegetables and water in a ratio of 1:2; and (3) filling the pulped kelp liquid and vegetable liquid into a sterilized triangular flask, inoculating the activated strain of the Weissella Greek strain L-1 according to the inoculum size of 2% by volume and mass, standing and fermenting for 6 days at a temperature of 20-25 ℃ to obtain the kelp fermentation product.

8. The method of claim 7, wherein: the volume ratio of the kelp liquid to the vegetable liquid after beating, which is mixed before inoculation, is 1:3.