Pediococcus acidilactici JW-015 as well as selenium-rich microbial inoculum and application thereof

Abstract

The invention discloses pediococcus acidilactici JW-015 as well as a selenium-rich microbial inoculum and application thereof, and belongs to the technical field of biology. According to the invention, a strain of pediococcus JW-015 which not only can be enriched with inorganic selenium, but also has oxidation resistance and ethanol tolerance is screened out, and the pediococcus JW-015 has huge potential and application value in the aspect of developing hangover-alleviating related probiotic health-care foods and medicines.

Description

Technical Field

[0001] The invention relates to a Pediococcus acidilactici JW-015 and a selenium-enriched bacterial agent and application thereof, belonging to the field of biotechnology. Background Art

[0002] As an essential trace element for the human body, selenium plays a key role in anti-oxidation, cancer prevention, detoxification and immunity enhancement. Selenium can be used in various forms, and different forms of selenium have great differences in biological activity and toxicity. Nano-selenium, due to its unique nano-scale, shows higher bioavailability and antioxidant capacity, and is an ideal form of selenium supplementation.

[0003] Nano-selenium prepared by traditional chemical synthesis has problems such as poor stability and high cost. In contrast, nano-selenium prepared by microbial reduction has significant advantages. In recent years, many scholars have studied the use of Pediococcus for absorption and conversion to obtain nano-selenium. Certain results have been achieved in the research on selenium-enriched production technology, the screening of selenium-enriched strains and fermentation processes, which provides an important theoretical basis for the potential development and application of nano-selenium. However, the Pediococcus reported and applied at present generally has low tolerance to inorganic selenium, and the research on the characteristics of strains synthesizing nano-selenium and the biological activity of selenium-enriched Pediococcus is relatively limited. Pediococcus with a single function may have limitations in dealing with complex health problems. Modern people face a variety of health problems, including nutritional deficiencies, oxidative stress, alcohol-related diseases and metabolic disorders. Pediococcus with selenium-enriched, antioxidant, alcohol-decomposing and triglyceride-degrading functions can provide multiple health benefits in a single strain while solving the above problems and achieving comprehensive protection of health. The existing technology lacks edible strains that can tolerate high concentrations of inorganic selenium and have selenium-enriched, antioxidant, alcohol-decomposing and triglyceride-degrading properties. Summary of the invention

[0004] In order to solve the above technical problems, the Pediococcus sp. JW-015 screened out by the present invention can not only tolerate high concentrations of inorganic selenium, but also grow stably in the environment, convert highly toxic inorganic selenium into low-toxic nano-selenium, and at the same time has good antioxidant properties and alcohol decomposition capabilities, and has application value in probiotic health foods for selenium supplementation and alcohol sobering.

[0005] The present invention provides a highly selenium-resistant and highly selenium-rich Pediococcus sp. JW-015. The Pediococcus sp. JW-015 has been deposited in the China Center for Type Culture Collection on May 30, 2024, with a deposit number of CCTCC NO: M20241097.

[0006] The present invention separates Pediococcus from healthy human feces, and the colony and bacterial characteristics of the strain obtained after screening are as follows: after culturing on MRS medium for 24 hours, the colony is white, translucent, convex, with clear edges, moist and shiny surface, and the colony diameter is 1.0-2.5 mm. The cell morphology is observed under an optical microscope, and Gram staining is G + The bacteria are spherical in shape, and the cells generally grow in pairs. Solitary ones are relatively rare, and they are not arranged in chains.

[0007] In one embodiment, the Pediococcus JW-015 can grow on an MRS plate with a sodium selenite concentration of 80 mM after domestication, and the selenium-enriched content reaches 1850 μg Se / g after being cultured in an MRS liquid medium supplemented with 10 mg / L sodium selenite for 48 hours. Its antioxidant capacity is significantly improved after selenium enrichment. The strain also performed well in the high-concentration alcohol tolerance experiment. Not only is the alcohol tolerance of the existing strains higher (it can still survive and reproduce after 48 hours of 18% alcohol stress treatment), but it also has a higher alcohol consumption capacity, and has a certain protective and preventive effect on alcoholic liver damage. Specifically:

[0008] In one embodiment, the strain is streaked on MRS solid plates with sodium selenite concentrations of 5, 10, 15, 20, 40, 60, 80, 100, and 120 mM in sequence and cultured at 37° C. for 72 hours. The strain can grow on a plate with a maximum of 80 mM.

[0009] In one embodiment, the strain is cultured in MRS liquid culture medium supplemented with 10 mg / L sodium selenite at 37° C. for 48 hours, and the selenium enrichment is measured using the first method of hydride generation atomic fluorescence spectroscopy of GB5009.93-2017, and the selenium enrichment content is 1850 μgSe / g.

[0010] In one embodiment, after the selenium-enriched treatment, the antioxidant capacity of the Pediococcus strain was significantly improved. Its SOD (superoxide dismutase) enzyme activity was enhanced to 2.99 times the original. At the same time, the total reducing power was increased by 1.16 times compared with that before the selenium-enriched treatment.

[0011] In one embodiment, the strain is subjected to 0%, 5%, 8%, 10%, 12%, 15%, and 18% (volume fraction) alcohol stress treatment, and after culturing for 48 hours, it can still survive and reproduce. Compared with growth under normal conditions, the growth rate of the bacteria is as follows:

[0012] Pediococcus: 100%, 82.9%, 62.1%, 44.7%, 36.0%, 19.8%, 10.8%;

[0013] Selenium-enriched Pediococcus: 100%, 87.4%, 70.18%, 66.8%, 43.9%, 20.5%, 16.3%.

[0014] In one embodiment, the strain is cultured to the end of logarithmic growth phase, and then 20% and 40% anhydrous ethanol are added respectively, and cultured at 37° C. for 24 hours.

[0015] In one embodiment, under the condition of 20%, the alcohol consumption ratio is: 4.3% (Pediococcus), 7.0% (Selenium-enriched Pediococcus).

[0016] In one embodiment, under the condition of 40%, the alcohol consumption ratio is: 7.7% (Pediococcus), 11.0% (Selenium-enriched Pediococcus).

[0017] The present invention also provides a microbial agent containing the Pediococcus JW-015.

[0018] In one embodiment, the microbial agent contains living cells, dead cells, strain lysate, fermentation broth or metabolites of the Pediococcus JW-015.

[0019] The present invention also provides a product containing the Pediococcus JW-015 or the microbial agent.

[0020] In one embodiment, the product includes food, medicine or health care product; the food includes dairy products, soy products or vegetable products; the medicine includes traditional Chinese medicine, chemical medicine or biological medicine.

[0021] The present invention also provides a method for reducing selenium, wherein the Pediococcus JW-015 or a microbial agent containing the Pediococcus JW-015 is added to a selenium-containing culture medium for culturing.

[0022] In one embodiment, the culture is carried out at 30-37°C for at least 48 hours.

[0023] In one embodiment, the selenium-containing culture medium contains an inorganic selenium salt; optionally, the inorganic selenium salt includes nitrite.

[0024] In one embodiment, the culture medium contains 10-50 mg / L of inorganic selenium salt.

[0025] The present invention also provides the use of the Pediococcus JW-015 or a microbial agent containing the Pediococcus JW-015 in the preparation of a health product that maintains a healthy blood lipid level or has an auxiliary protective effect on chemical liver damage.

[0026] The present invention also provides the use of the Pediococcus JW-015 or a microbial agent containing the Pediococcus JW-015 in the preparation of medicines for lowering blood lipids or sobering up and protecting the liver.

[0027] Beneficial effects:

[0028] (1) The present invention screened out a Pediococcus JW-015, which is a new species of Pediococcus. The strain has a high resistance to selenium and can grow on a plate added with 80 mM sodium selenite. The selenium resistance is higher than that of the reported Pediococcus strains. In a liquid culture medium added with 10 mg / L sodium selenite, the strain converts highly toxic inorganic selenium into low-toxic nano-selenium, and the selenium-rich content can reach 1850 μgSe / g, showing broad application prospects.

[0029] (2) A key to preparing selenium-enriched probiotics is to achieve a balance between the amount of selenium and the biological activity of the probiotics. In the present invention:

[0030] Analysis of antioxidant activity: Compared with the non-selenium-enriched group, the SOD enzyme activity of selenium-enriched Pediococcus JW-015 increased by 2.99 times, and the total reducing power increased by 1.16 times. Selenium enrichment significantly improved the antioxidant capacity of the strain.

[0031] Analysis of the alcohol sobering activity: Compared with the 10% tolerance in most literature, the survival rate of Pediococcus JW-015 reached 11.40% at an ethanol concentration of 18%, which has a high resistance to alcohol stress. After selenium enrichment, the survival rate of the strain reached 16.30%, and the resistance to alcohol stress was significantly improved. Pediococcus JW-015 can effectively use ethanol as one of the carbon sources, thereby playing a role in degrading ethanol. After selenium enrichment, the consumption of anhydrous ethanol can reach up to 11.02%, which is 1.43 times that of the non-selenium-enriched group under the same conditions. In addition, compared with the non-selenium-enriched group, the activity of alcohol dehydrogenase, acetaldehyde dehydrogenase and triglyceride reduction rate of selenium-enriched Pediococcus increased by 49.06%, 81.30% and 35.65% respectively. Therefore, this strain and its selenium-enriched bacterial agent have great potential and application value in the field of alcohol sobering.

[0032] Biomaterial Deposit

[0033] A strain of Pediococcus sp. JW-015, classified and named Pediococcus sp. JW-015, was deposited in the China Center for Type Culture Collection on May 30, 2024, with the deposit number CCTCC NO: M 20241097, and the deposit address is Wuhan University, Wuhan, China. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The scanning electron micrographs of the strains in Example 3 of the present invention are shown in FIG. 1 , wherein: (a) a scanning electron micrograph of Pediococcus JW-015; and (b) a scanning electron micrograph of Selenium-enriched Pediococcus JW-015.

[0035] Figure 2These are the growth curve of the strain, the reduction curve of sodium selenite and the generation curve of nano-selenium in Example 4 of the present invention under the condition of adding 10 mg / L sodium selenite (Note: 10 mg / L sodium selenite can be converted to 57.82 μM).

[0036] Figure 3 This is the total reducing power standard curve of Example 5 of the present invention. DETAILED DESCRIPTION

[0037] The preferred embodiments of the present invention will be described in detail below in conjunction with examples. It should be understood that the following examples are provided only for the purpose of illustration and are not intended to limit the scope of the present invention. Those skilled in the art may make various modifications and substitutions to the present invention without departing from the purpose and spirit of the present invention.

[0038] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples are all commercially available unless otherwise specified.

[0039] The culture medium involved in the following examples is:

[0040] MRS liquid culture medium: add 10.0 g of peptone, 10.0 g of beef extract, 5.0 g of yeast extract, 1.0 mL of Tween 80, 2.0 g of dipotassium hydrogen phosphate, 0.5 g of magnesium sulfate, 2.0 g of ammonium citrate, 20.0 g of glucose, 0.25 g of manganese sulfate, and 5.0 g of sodium acetate to 1000 mL of distilled water; mix and dissolve, adjust the pH to 6.0-6.4, and sterilize at 121°C for 15 min.

[0041] MRS solid medium: Add 2.5% agar powder to MRS liquid medium.

[0042] MRS-triglyceride liquid medium: Mix 10 g of triglyceride and 30 mL of 2% polyvinyl alcohol, stir continuously for 20 min, and add 3% of the mixture to the sterilized MRS liquid medium in a clean bench.

[0043] Example 1 Screening, Isolation and Identification of Pediococcus

[0044] The following experiments were performed under sterile conditions.

[0045] 1. Enrichment of strains

[0046] The sample (10 g) was added to a sterile physiological saline solution (90 mL) containing 10 mg / L sodium selenite and enriched in a constant temperature shaker at 37°C and 200 rpm for 2 h. Under sterile conditions, 1 mL of the enriched sample was taken and diluted to 10 with sterile water in a ten-fold gradient dilution method. -6 , take 100mL of dilution of 10-3 -10 -6 The sample solution was spread on MRS plates, 3 plates were spread for each dilution, and placed in an anaerobic box and cultured at 37°C for 24 h until visible colonies appeared on the plates.

[0047] 2. Isolation of strains

[0048] The colonies obtained in step 1 were picked up and examined under a microscope using Gram staining to observe the bacterial morphology, and different colony morphologies and Gram-positive bacteria were selected as target strains.

[0049] 3. Purification of strains

[0050] Pick the colonies obtained in step 2 and streak them on the MRS plate. Repeat the purification until there are no other bacteria. Record the status of colonies of different strains and select large and full colonies.

[0051] 4. Identification of strains

[0052] After the purified strain in step 3 was inoculated into a vial and cultured for 24 hours, the genome was extracted using a genome extraction kit for 16S rDNA sequencing. The sequence homology was compared and analyzed using the BLAST search system of NCBI. The comparison result with the highest similarity showed that Pediococcus had a homology of 99.86%.

[0053] The 16SrDNA sequence of Pediococcus sp. JW-015 of the present invention is as follows (SEQ ID NO.1):

[0054]

[0055] Example 2 Preparation of a Bio-nanoselenium-rich Probiotic Preparation by Fermentation with Pediococcus JW-015

[0056] Primary activation: inoculate the bacterial solution stored in the glycerol tube into MRS liquid culture medium under sterile conditions, and culture at 37°C for 24 hours to obtain the activated seed solution.

[0057] Secondary activation: The primary activated bacterial solution was inoculated with MRS liquid culture medium at a 2% inoculation rate and cultured at 37°C for 24 hours to obtain activated fermentation liquid.

[0058] Pediococcus JW-015 group: Take the above activated fermentation broth and add it to the MRS liquid medium without sodium selenite at a 2% inoculum until the OD 600 The concentration of 0.1 was 0.1, and the mixture was cultured at 37°C for 24 h. The bacterial solution was collected to obtain a liquid preparation of Pediococcus JW-015. The number of viable bacteria in the liquid preparation was 2×10 8 CFU / mL.

[0059] The bacterial solution was centrifuged (2000 r / min, 15 min), washed repeatedly with sterile saline for 5 times, and then centrifuged again to collect the precipitate for subsequent experiments.

[0060] The precipitate is dried to obtain a Pediococcus JW-015 solid preparation.

[0061] Selenium-enriched Pediococcus JW-015 group:

[0062] Take the above activated fermentation broth and add it to MRS liquid medium with a sodium selenite concentration of 10 mg / L at a 2% inoculum until the OD 600 The concentration of the culture medium was 0.1, and the culture was carried out at 37°C for 24 h. The bacterial solution was collected to obtain a liquid preparation of selenium-enriched Pediococcus JW-015. The number of viable bacteria in the liquid preparation was 2×10 8 CFU / mL.

[0063] The bacterial solution was centrifuged (2000 r / min, 15 min), washed repeatedly with sterile saline for 5 times, and then centrifuged again to collect the precipitate for subsequent experiments.

[0064] The precipitate is dried to obtain a selenium-enriched Pediococcus JW-015 solid preparation.

[0065] Example 3 Localization of Nano-Selenium Synthesized by Pediococcus JW-015 in Cells

[0066] SEM analysis:

[0067] The Pediococcus JW-015 solid preparation and the selenium-enriched Pediococcus JW-015 solid preparation in Example 4 were taken and imaged and photographed using a scanning electron microscope.

[0068] Scanning electron microscopy is an effective method for observing morphology and structure. The fermentation products of Pediococcus JW-015 before and after selenium enrichment were examined by scanning electron microscopy to observe the effect of selenium on the bacterial surface morphology. Figure 1 As shown, the bacteria are spherical, and the cells are usually paired, with no sediment on the surface. The surface of the selenium-enriched strain has spherical particles of different sizes, which are wrapped by the secretions of the bacteria. This phenomenon may be caused by Pediococcus JW-015 reducing selenite to elemental selenium for cell detoxification.

[0069] Example 4 Analysis of the tolerance and reducing ability of Pediococcus JW-015 to inorganic selenium

[0070] 1. Determination of tolerance to inorganic selenium

[0071] The Pediococcus JW-015 isolated and screened in Example 1 was streaked on an MRS plate containing different sodium selenite concentrations to observe its growth. Sodium selenite solution was added to the MRS medium to prepare MRS solid plates with sodium selenite concentrations of 5, 10, 15, 20, 40, 60, 80, 100, and 120 mM, and the Pediococcus was transferred in sequence and cultured at 37°C for 72 hours. The results showed that the strain could grow on an MRS plate with 80 mM (13.84 g / L) sodium selenite added at most, and compared with the tolerance in most literatures, it was a strain with high resistance to inorganic selenium stress.

[0072] 2. Determination of selenium content

[0073] The culture medium of Pediococcus JW-015 was fermented to 2×10 8 CFU / mL, inoculated with 2% inoculation in MRS liquid medium containing 10mg / L sodium selenite, and cultured in a 37°C incubator for 48h. The fermentation broth was centrifuged (8000r / min, 10min), the supernatant was discarded, the precipitate was washed with deionized water, centrifuged again, and the precipitate was washed repeatedly 3 times and placed in a 60°C oven to constant weight. The selenium-rich situation was determined by the first method of hydride generation atomic fluorescence spectroscopy of GB5009.93-2017. The selenium-rich content was calculated to be 1850μgSe / g bacteria.

[0074] 3. Analysis of the reducing ability of inorganic selenium

[0075] The culture medium of Pediococcus JW-015 was fermented to 2×10 8 CFU / mL, inoculated with 2% inoculum in MRS liquid medium containing 10 mg / L sodium selenite, cultured at 37°C, and measured the OD of the culture medium every 6 h using turbidimetry. 600Until 48h, the medium without added sodium selenite substrate was used as the control group, and the growth curve was drawn to examine the growth pattern of the bacteria before and after the addition of sodium selenite.

[0076] Every 4 hours, 1 mL of the fermentation liquid was taken into a 2 mL centrifuge tube and centrifuged at 8000 r / min for 10 min. The cells and supernatant were collected to determine the SeO3 2- reduction efficiency and the content of generated nano-selenium.

[0077] The results are as follows Figure 2 . The growth curve of the selenium-added strain was basically the same as that of the control group without selenium, indicating that this concentration of sodium selenite had almost no effect on the growth of the strain. In addition, the reduction of sodium selenite and the formation of elemental selenium by the strain is a continuous process related to the growth dynamics of the strain. The sodium selenite reduction rate was 17.2% within 12 hours, and more than 65% of the sodium selenite was reduced in the logarithmic phase (8h-24h). At 36-48h, the sodium selenite consumption tended to be stable, and the final sodium selenite reduction rate was 82.67%. Among them: the sodium selenite reduction rate refers to the proportion of sodium selenite (Na2SeO3) reduced to other forms (such as elemental selenium or other selenium compounds) under certain conditions.

[0078] Example 5 Antioxidant capacity detection of nano-selenium-rich Pediococcus

[0079] 1. Determination of SOD enzyme activity

[0080] The bacterial precipitates of Pediococcus JW-015 and Selenium-enriched Pediococcus JW-015 in Example 2 were collected respectively, and the SOD enzyme activity was determined by the WST-1 method. WST-1 (Water-Soluble Tetrazolium-1) is a water-soluble tetrazolium salt, which can be reduced as an electron acceptor in a specific chemical reaction to form a colored formazan compound, and the product has an obvious absorption peak at a wavelength of 450nm. The SOD enzyme can catalyze the conversion of superoxide anions (O 2- ) is disproportionated to generate hydrogen peroxide (H2O2) and oxygen (O2), thereby inhibiting the reaction to generate formazan, thereby indirectly evaluating the activity of SOD enzyme. Follow the instructions of the kit. SOD calculation formula in tissue:

[0081]

[0082] A0: SOD inhibition rate; A1: reaction system dilution multiple; A2: dilution multiple before test;

[0083] A3: added homogenization buffer (mL); A4: tissue weight (g);

[0084] Definition: In this system, the amount of enzyme corresponding to a 50% SOD inhibition rate is one SOD activity unit (U).

[0085] The measurement results are shown in Table 1:

[0086] Table 1

[0087]

[0088] 2. Determination of total reducing power

[0089] Take 0.5 ml of the above-mentioned Pediococcus JW-015 liquid preparation and selenium-enriched Pediococcus JW-015 liquid preparation, add 0.5 ml of 1% K3[Fe(CN)6] solution and 0.5 ml of PBS buffer and mix thoroughly, place in a 50°C water bath for 20 min, immediately add 0.5 ml of 10% trichloroacetic acid to terminate the reaction, and centrifuge at 3000 r / min for 5 min. 1 ml of supernatant, 1 ml of water and 1 ml of 1% FeCl3 solution are mixed evenly, allowed to stand at room temperature for 10 min, and the absorbance at 700 nm is measured. 625 μmol / L L-cysteine ​​hydrochloride standard solution is diluted with different concentrations, and a standard curve is prepared according to the above method, such as Figure 3 shown.

[0090] There is a significant correlation between reducing ability and antioxidant capacity, so reducing ability can be used as an effective indicator to evaluate antioxidant capacity. L-cysteine ​​is a natural antioxidant that can increase the body's glutathione level and reflect the reducing ability of the strain. The results showed that the reducing ability of the strain was equivalent to 2602.86μmol / L of L-cysteine ​​hydrochloride, and its reducing ability after selenium enrichment was equivalent to 3017.14μmol / L of L-cysteine ​​hydrochloride.

[0091] In summary, the antioxidant capacity and reducing capacity of Pediococcus JW-015 were greatly improved after being enriched with selenium.

[0092] Example 6 Application test of alcohol tolerance and metabolism of nano-selenium-rich Pediococcus

[0093] 1. Determination of alcohol stress tolerance

[0094] The Pediococcus JW-015 liquid preparation and the selenium-enriched Pediococcus JW-015 liquid preparation described in Example 2 were added to MRS liquid culture medium with different mass fractions (5%, 8%, 10%, 12%, 15%, 18%) of alcohol at a 2% inoculation rate and placed in a 37°C incubator for alcohol stress for 48 h. At the same time, the MRS culture medium group without alcohol was used as a negative control. 600 Compare their growth conditions.

[0095] As shown in Table 2, with the increase of alcohol concentration, the tolerance of Pediococcus decreased. After 18% alcohol stress, Pediococcus JW-015 could still maintain a survival rate of 11.4%. After 18% alcohol stress, the survival rate of Pediococcus JW-015 after selenium-enriched culture increased to 16.3%, which was 1.43 times that before selenium enrichment.

[0096] Table 2 Growth of Pediococcus after 48h treatment with different concentrations of alcohol

[0097]

[0098]

[0099] Compared with the 10% tolerance in most literature, this strain has a very high resistance to alcohol stress, and after selenium enrichment, the strain's resistance to alcohol stress is significantly improved.

[0100] 2. Determination of alcohol consumption capacity

[0101] Take equal volumes of the Pediococcus JW-015 liquid preparation and the selenium-enriched Pediococcus JW-015 liquid preparation described in Example 2, add anhydrous ethanol with a final concentration of 20% and 40% respectively, and culture at 37°C for 24 hours. Take the MRS ethanol culture medium without bacterial solution as a control, and use the potassium dichromate-sulfuric acid method to determine the ethanol degradation ability of the strains. Ethanol consumption % = residual ethanol amount in the control group - residual ethanol amount in the experimental group.

[0102] The results are shown in Table 3. Under the condition of ethanol concentration of 20%, the Pediococcus group can consume 4.24% of anhydrous ethanol, and the selenium-enriched Pediococcus group can consume 7.00% of anhydrous ethanol; when the ethanol concentration is increased to 40%, the sample group can consume 7.69% of anhydrous ethanol, and the selenium-enriched group consumes anhydrous ethanol to 11.02%. This shows that under the ethanol volume fraction of 20% and 40%, Pediococcus JW-015 can effectively use ethanol as one of the carbon sources, thereby playing a role in degrading ethanol, and the effect of consuming anhydrous ethanol is better after selenium enrichment.

[0103] Table 3 Residual alcohol ratio of Pediococcus fermentation liquid before and after selenium enrichment

[0104]

[0105] 3. Determination of alcohol dehydrogenase activity

[0106] ADH in the presence of oxidized coenzyme NAD + In the weak alkaline range, it catalyzes the dehydrogenation reaction of ethanol to produce acetaldehyde. +It is reduced to reduced coenzyme NADH, which has a maximum absorption peak at 340nm. The enzyme activity is obtained by measuring the change rate of absorbance at 340nm. Take the liquid preparation of Pediococcus JW-015 and the liquid preparation of Selenium-enriched Pediococcus JW-015 in Example 2, centrifuge, wash with PBS 2-3 times, and collect the bacterial precipitate. Operate according to the instructions of the kit. ADH calculation formula in tissue:

[0107]

[0108] Definition: At 25°C, the amount of enzyme that oxidizes 1 nmol NADH per gram of tissue per minute is defined as 1 enzyme activity unit.

[0109] The test results are shown in Table 4. The activity of alcohol dehydrogenase in Pediococcus JW-015 is 92.58 U / g. After selenium enrichment, the activity of alcohol dehydrogenase is 138.00 U / g, which is increased by 49.06%.

[0110] Table 4

[0111]

[0112] 4. Determination of acetaldehyde dehydrogenase activity

[0113] In the presence of coenzyme I, acetaldehyde dehydrogenase catalyzes the reaction of acetaldehyde with NAD + The absorbance at 340 nm will increase when converted into acetic acid and NADH. The activity of acetaldehyde dehydrogenase can be calculated by measuring the change in absorbance at 340 nm. The liquid preparation of Pediococcus sp. JW-015 and the liquid preparation of Selenium-enriched Pediococcus sp. JW-015 in Example 2 were centrifuged, washed with PBS for 2-3 times, and the bacterial precipitate was collected. The operation was performed according to the instructions of the kit.

[0114]

[0115] Definition: At 25°C, 1 nmol NAD is oxidized per gram of tissue per minute. + The amount of enzyme is defined as 1 unit of enzyme activity.

[0116] The test results are shown in Table 5. The activity of acetaldehyde dehydrogenase in Pediococcus JW-015 is 17.17 U / g. After selenium enrichment, the activity of acetaldehyde dehydrogenase is 31.13 U / g, which is increased by 81.30%.

[0117] Table 5

[0118]

[0119] 5. Determination of triglyceride content

[0120] The culture method of Pediococcus JW-015 is as shown in Example 2, except that, after the secondary activation, the activated fermentation broth of Pediococcus JW-015 is inoculated into MRS-triglyceride liquid culture medium containing 10 mg / L sodium selenite (selenium-enriched Pediococcus JW-015) and without sodium selenite (Pediococcus JW-015), respectively, and cultured at 37° C. for 72 h. The absorbance at 500 nm is determined using a triglyceride determination kit, and the control group is an MRS-triglyceride liquid culture medium without bacterial solution.

[0121] Under the action of lipase, glycerol kinase, 3-phosphoglycerol oxidase and peroxidase, triglycerides are gradually converted and finally form quinones. The darker the color of the quinone compounds, the higher the triglyceride content. The test results show that before selenium enrichment, the Pediococcus JW-015 can reduce triglycerides by 30.74%, and after selenium enrichment, the reduction rate of triglycerides by Pediococcus JW-015 is 41.70%.

[0122] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A Pediococcus sp. JW-015, which was deposited in the China Center for Type Culture Collection on May 30, 2024, with a deposit number of CCTCC NO: M 20241097.

2. A microbial agent containing the Pediococcus JW-015 according to claim 1.

3. The microbial agent according to claim 2, characterized in that: The microbial inoculant contains living cells, dead cells, strain lysate, fermentation broth or metabolites of the Pediococcus JW-015.

4. A product containing the Pediococcus JW-015 according to claim 1, or the microbial agent according to claim 2 or 3.

5. The product according to claim 4, characterized in that The products include food, medicine or health products; the food includes dairy products, soy products or vegetable products; the medicine includes traditional Chinese medicine, chemical medicine or biological medicine.

6. A method for reducing selenium, characterized in that: The Pediococcus JW-015 according to claim 1, or the microbial agent according to claim 2 or 3 is added to a selenium-containing culture medium for culturing.

7. The method according to claim 6, characterized in that Incubate at 30-37°C for at least 48 h.

8. The method according to claim 6, characterized in that The selenium-containing culture medium contains selenium salt; optionally, the selenium salt includes nitrite.

9. Use of the Pediococcus JW-015 according to claim 1, or a microbial agent containing the microbial agent according to claim 2 or 3, in the preparation of a health product for maintaining healthy blood lipid levels or having an auxiliary protective effect against chemical liver damage.

10. Use of Pediococcus JW-015 according to claim 1, or a microbial agent containing the microbial agent according to claim 2 or 3, in the preparation of a drug for lowering blood lipids or sobering up and protecting the liver.

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