Lactobacillus paracasei YM2024 for degrading pesticide residues, fermentation product, flora YM-Clean and application

Abstract

The invention belongs to the technical field of microorganisms, and particularly relates to a Lactobacillus paracasei YM2024 strain for degrading pesticide residues, a flora YM-Clean and application of the Lactobacillus paracasei YM2024 strain and the flora YM-Clean. The lactobacillus paracasei YM2024 has been preserved in the China General Microbiological Culture Collection Center on January 25, 2024, and the preservation number of the lactobacillus paracasei YM2024 is CGMCC No. 29770. The strain has an adsorption effect on pesticides, also has relatively high alkaline phosphatase activity, and can degrade various organophosphorus pesticides under in-vivo conditions, so that the damage of the pesticides to intestinal flora and intestinal barriers can be relieved, and the damage of pesticide residues to organisms can be reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of microorganisms, and in particular relates to a Lactobacillus paracasei YM2024 strain capable of degrading pesticide residues, a bacterial community YM-Clean and applications. Background Art

[0002] With the development of agriculture, the use of pesticides has become more and more widespread, but pesticide residues have caused serious impacts on the environment and human health. Pesticides usually enter the body with unwashed fruits, vegetables and other foods, causing damage to health by destroying the intestinal barrier and entering the human circulation, causing obesity, liver and kidney damage and other diseases. Therefore, it is of great significance to develop a method that can effectively degrade pesticide residues. As a green and environmentally friendly technology, microbial degradation technology has become an effective way to solve the problem of pesticide residues. The ways to solve the problem of pesticide residues by microorganisms mainly include adsorption and degradation, but the effects of existing microorganisms in adsorbing and degrading pesticides need to be further improved. Summary of the invention

[0003] In view of the above technical problems, the present invention provides a strain of Lactobacillus paracasei YM2024, a bacterial community YM-Clean and an application thereof for degrading pesticide residues. The Lactobacillus paracasei YM2024 strain can produce a significant adsorption effect on organophosphorus pesticides, and in an intestinal environment with complex components, the strain can also produce an excellent pesticide degradation effect, thereby effectively reducing the harm of organophosphorus pesticides to the human body.

[0004] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions: The first aspect of the present invention provides a strain of Lactobacillus paracasei YM2024, whose classification name is Lactobacillus paracasei ( Lacticaseibacillus paracasei ), deposited in the General Microbiology Center of China Microorganism Culture Collection on January 25, 2024, with the deposit number CGMCC No. 29770; the deposit address is Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing.

[0005] Lactobacillus paracasei is a probiotic widely present in the human intestine, has multiple physiological functions, can regulate the balance of intestinal flora, inhibit the growth of harmful bacteria, and enhance the intestinal barrier. The Lactobacillus paracasei YM2024 strain provided by the present invention is obtained by screening from traditional dairy products, and in addition to having the common physiological activity of Lactobacillus paracasei, it also has an adsorption effect on pesticides, and has a high alkaline phosphatase activity, and can degrade a variety of organophosphorus pesticides under in vivo conditions, thereby being able to alleviate the damage of pesticides to intestinal flora and intestinal barrier, and reduce the damage of pesticide residues to the body.

[0006] The second aspect of the present invention provides the use of the Lactobacillus paracasei YM2024 strain in reducing pesticide residues.

[0007] The third aspect of the present invention provides the use of the Lactobacillus paracasei YM2024 strain in absorbing pesticide residues in liquid.

[0008] The application method specifically includes the following operations: The live bacteria and / or inactivated bacteria of the Lactobacillus paracasei YM2024 strain are added to the liquid to be treated, and the liquid is kept at 35-39° C. for at least 4 hours to separate the bacteria.

[0009] The Lactobacillus paracasei YM2024 strain has a high alkaline phosphatase activity, and can produce an adsorption effect similar to activated carbon after inactivation. Therefore, both its live bacteria and inactivated bacteria can adsorb pesticides in liquids and reduce the content of pesticides in liquids.

[0010] Preferably, the pesticide is an organophosphorus pesticide.

[0011] Further preferably, the pesticide includes at least one of dimethoate, chlorpyrifos and glufosinate-ammonium.

[0012] Preferably, the concentration of the live bacteria or inactivated bacteria in the liquid to be treated is 10 7 cfu / mL~10 9 cfu / mL.

[0013] The fourth aspect of the present invention provides the use of the above-mentioned Lactobacillus paracasei YM2024 strain in degrading pesticides.

[0014] Preferably, the application is the application of degrading pesticide residues in the intestine.

[0015] Preferably, the pesticide is an organophosphorus pesticide.

[0016] Further preferably, the pesticide includes at least one of dimethoate, chlorpyrifos and glufosinate-ammonium.

[0017] A fifth aspect of the present invention provides a probiotic powder prepared from the above-mentioned Lactobacillus paracasei YM2024 strain.

[0018] In an eighth aspect, the present invention provides a bacterial flora YM-Clean capable of degrading pesticide residues, comprising the above-mentioned Lactobacillus paracasei YM2024 and at least one other bacterial strain capable of degrading pesticide residues.

[0019] Preferably, the strain having the ability to degrade pesticide residues includes animal Bifidobacterium lactis subspecies BAL-28, which has been deposited in the General Microbiological Center of the China Microbiological Culture Collection Administration Committee on June 26, 2022, with a deposit number of CGMCC No.7.462. The strain has been disclosed in a patent with application number CN202310956580.0, entitled "Animal Bifidobacterium lactis subspecies BAL-28 and fermentation products, flora CW and applications for preventing indigestion and flatulence and promoting absorption".

[0020] The beneficial effects of the present invention are: The Lactobacillus paracasei YM2024 strain provided by the present invention has a higher alkaline phosphatase activity and has the ability to degrade organophosphorus pesticides. The strain can not only adsorb pesticides under in vitro conditions, but also promote pesticide degradation in an intestinal in vitro fermentation simulation system. In addition, experiments have shown that the Lactobacillus paracasei YM2024 strain can colonize in the human intestine and can survive for more than one week in the intestinal environment, so it has the potential to continuously degrade agricultural residues. At the same time, the Lactobacillus paracasei YM2024 is more in line with the situation that multiple pesticides may remain in fruits and vegetables in practical applications, and has an excellent degradation effect on mixed pesticides containing dimethoate, chlorpyrifos, and glufosinate. Therefore, the strain can reduce the pesticides in fruits and vegetables by soaking and other methods, and can also reduce the pesticides in the body by oral administration, thereby reducing the damage of pesticides to the body. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The cell morphology of Lactobacillus paracasei YM2024 in Example 1; Figure 2 It is the colony morphology of Lactobacillus paracasei YM2024 in Example 1. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work fall within the scope of protection of the present invention.

[0023] The scheme of the present invention is described below through specific embodiments.

[0024] The components and preparation methods of the culture medium used in the following examples are as follows: Improved MRS liquid medium: peptone 10.0 g, beef extract powder 5.0 g, yeast extract powder 4.0 g, glucose 20.0 g, Tween-80 1.0 ml, dipotassium hydrogen phosphate 2.0 g, sodium acetate 5.0 g, triammonium citrate 2.0 g, agar 15.0 g, magnesium sulfate (MgSO4·7H2O) 0.2 g, manganese sulfate (MnSO4·4H2O) 0.05 g, distilled water 1000 mL, pH 6.2±0.2.

[0025] Intestinal model medium (CMGM) (g / L): starch, 5.0; pectin, 2.0; guar gum, 1.0; mucin (porcine stomach type III), 4.0; xylan, 2.0; arabinogalactan, 2.0; inulin, 1.0; casein, 3.0; peptone water, 5.0; tryptone, 5.0; bile salt, 0.4; yeast extract, 4.5; ferrous sulfate (FeSO4·7H2O), 0.005; sodium chloride, 4.5; potassium chloride, 4.5; potassium dihydrogen phosphate (KH2PO4), 0.5; magnesium sulfate (MgSO4·7H2O), 1.25; calcium chloride (CaCl2·6H2O), 0.15; sodium bicarbonate (NaHCO3), 1.5; cysteine, 0.8; heme, 0.05; Tween 80, 1.0.

[0026] Unless otherwise specified, the technical means used in the following examples are conventional means well known to those skilled in the art; the materials, reagents, etc. used in the following examples can be obtained from commercial channels.

[0027] Example 1 The embodiment of the present invention provides a Lactobacillus paracasei YM2024 strain and an acquisition process and an identification process thereof.

[0028] 1. Acquisition process On September 12, 2019, the Lactobacillus paracasei YM2024 strain was obtained from local traditional yogurt obtained in Taxkorgan Tajik Autonomous County (4000 m above sea level, 35°37′-38°40′N, 71°20′-77°01′E).

[0029] 2. Identification 2.1 Colony morphology observation Cell morphology: Polymorphic bacilli (e.g. Figure 1 As shown); Colony morphology observation: The surface is smooth and shiny (as shown Figure 2 Gram stain: positive.

[0030] 2.2 16S rDNA sequencing 16S rDNA sequence of Lactobacillus paracasei YM2024 (as shown in SEQ ID No.1):

[0031] By performing BLAST sequence alignment in the NCBI database, the Lactobacillus paracasei YM2024 was compared with Lactobacillus paracasei ( Limosilactobacillus reuteri )’s Identity = 99.93%.

[0032] Through cell morphology observation, colony morphology observation, Gram staining and 16S rDNA sequence comparison, the strain was different from Lactobacillus paracasei ( Limosilactobacillus reuteri The Lactobacillus paracasei YM2024 was deposited in the General Microbiology Center of China Microbiological Culture Collection Administration (address: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, zip code 100101), with the deposit number CGMCC No. 29770.

[0033] Example 2 This embodiment provides a bacterial suspension of Lactobacillus paracasei YM2024 strain, and its preparation method is as follows: The seed liquid of Lactobacillus paracasei YM2024 was inoculated into the modified MRS liquid medium and activated for three generations. The obtained bacteria were adjusted to the concentration of the bacterial liquid with PBS to obtain the bacterial suspension.

[0034] Example 3 The present embodiment provides a YM2024 probiotic powder, and the preparation method thereof is as follows: adding Lactobacillus paracasei YM2024 at an inoculum amount of 3% to a culture medium for fermentation culture, and the culture conditions are: 37° C., 12 hours; after the fermentation is completed, centrifuging at 6000 r / min for 30 minutes to obtain bacterial sludge, mixing the bacterial sludge with a freeze-drying protective agent, freeze-drying the mixture, and then pulverizing the mixture to obtain YM2024 probiotic powder (the number of viable bacteria is 1.1×10 11 CFU / g).

[0035] Preparation method of culture medium: mix 40g glucose, 4g soy peptone, 3g yeast extract powder, 2g diamine hydrogen citrate, 6g anhydrous sodium acetate, 3g dipotassium hydrogen phosphate, 1g isomaltooligosaccharide, 3g starch and other food-grade materials, add 1000g pure water and mix until no particles are visible to the naked eye, adjust the pH to 5.0-6.8 after mixing the materials, and sterilize at 117.5-118.5℃ for 20min to obtain the culture medium.

[0036] Preparation method of freeze-dried protective agent: 100g starch, 20g glucose, 60g maltodextrin, 30g sucrose, 10g lactose, 50g skimmed milk powder and other food raw materials are mixed evenly, 1000g pure water is added to dissolve until no particles are visible to the naked eye, the pH is adjusted to 5.0-6.8 after the materials are dissolved, and sterilized at 117.5-118.5℃ for 20min. After sterilization, the pH is adjusted to 6.0-7.3 to obtain the freeze-dried protective agent.

[0037] Example 4 This example provides the alkaline phosphatase activity of Lactobacillus paracasei YM2024 strain and the adsorption and degradation effects of organophosphorus pesticides.

[0038] 1. Alkaline phosphatase activity assay of Lactobacillus paracasei YM2024 1.1 Treatment of Lactobacillus paracasei YM2024 Lactobacillus paracasei YM2024 was cultured in modified MRS medium at 37°C, activated for three generations, and centrifuged (12000 rpm / min) for 3 min to obtain bacterial sludge. The sludge was resuspended in 50 mM PBS, lysed by ultrasonic disruptor, and centrifuged at 4°C (12000 rpm / min) for 10 min to obtain the supernatant for later use.

[0039] 1.2 Alkaline phosphatase activity detection (1) Refer to Table 1 to set up blank control wells, standard wells, and sample wells in a 96-well plate. The volumes of standard working solution are 4, 8, 16, 24, 32, and 40 µL, respectively, and 50 µL is added directly to the sample.

[0040] Table 1 Group settings

[0041] (2) Mix by gently blowing with a pipette. Incubate at 37℃ for 10 min.

[0042] (3) Add 100 µL of the reaction stop solution in the Bio-Tech Alkaline Phosphatase Assay Kit (P0321S) to each well to terminate the reaction.

[0043] (4) Measure the absorbance at 405 nm.

[0044] The alkaline phosphatase activity of Lactobacillus paracasei YM2024 was tested to be 0.235±0.002 U / mL.

[0045] 2. Adsorption effect of Lactobacillus paracasei YM2024 on organophosphorus pesticides Take 3% of the bacterial solution and inoculate it into 10 mL of modified MRS liquid medium. Activate for 3 generations continuously. Centrifuge (12000 rpm / min) for 3 min to remove the bacteria. Wash them 3 times with 50 mM PBS. Adjust the concentration of the bacterial solution with 50 mM PBS to prepare 10 7 cfu / mL and 10 9 cfu / mL of live bacterial suspension for later use; take the live bacterial suspension and prepare the inactivated bacterial suspension in a water bath at 80℃ for 30 min. The commercially available Lactobacillus paracasei LPC12 was used as a control, and the treatment methods of its bacteria and inactivated bacteria were the same as those of YM2024. The live bacterial suspension and the inactivated bacterial suspension were added to the solutions of dimethoate (3 mg / L), chlorpyrifos (3 mg / L), and glufosinate (3 mg / L), respectively, cultured at 37℃ for 4 h, centrifuged (12000 rpm / min) for 3 min, and the supernatant was collected and detected by gas chromatography. The chromatographic conditions were as follows: the carrier gas was high-purity nitrogen with a flow rate of 10 mL / min; the fuel gas was high-purity H2 with a flow rate of 75 mL / min; the auxiliary gas was air with a flow rate of 100 mL / min. The injection port temperature was 200℃, the detector temperature was 250℃, the initial column box temperature was 90℃, retained for 1 min, increased to 260℃ at 10℃ / min, and retained for 3 min. The injection method was splitless injection, and the septum purge was 3 mL / min. A DB-1701 medium polarity capillary column, FPD detector, injection volume of 1.0 µL were used, and retention time was used for qualitative analysis and peak area for quantitative analysis. The experiment used a dimethoate solution without lactobacillus as a blank control and was treated in the same way. Each sample was paralleled in 3 groups and the experiment was repeated 3 times.

[0046] The results are shown in Table 2.

[0047] Table 2 Adsorption effect

[0048] Adsorption rate calculation formula: Adsorption rate (%) = (pesticide concentration before adding bacterial suspension - pesticide concentration after adding bacterial suspension) ÷ pesticide concentration before adding bacterial suspension × 100%.

[0049] It takes a long time for bacteria to degrade pesticides, but in this experiment, the contact time between bacteria and pesticides is short, so the reduction in pesticide concentration is mainly through adsorption that takes effect in the short term. Therefore, the change in pesticide concentration caused by pesticide degradation can be ignored in the calculation of adsorption rate.

[0050] As shown in Table 2, live and inactivated Lactobacillus paracasei YM2024 bacteria have good adsorption effects on dimethoate, chlorpyrifos and glufosinate. 9cfu / mL), the adsorption effect of live and inactivated Lactobacillus paracasei YM2024 on dimethoate and glufosinate was significantly better than that of live and inactivated Lactobacillus paracasei on chlorpyrifos. The adsorption effect of live Lactobacillus paracasei YM2024 on chlorpyrifos was better than that of live Lactobacillus paracasei on chlorpyrifos. At a lower concentration (1.0x10 7 cfu / mL), the adsorption effect of live and inactivated Lactobacillus paracasei YM2024 on chlorpyrifos was significantly better than that of commercially available Lactobacillus paracasei.

[0051] 3. Degradation effect of Lactobacillus paracasei YM2024 on pesticides in an in vitro intestinal fermentation simulation system The experiment was divided into four groups, a positive control group, a blank group, a commercially available Lactobacillus paracasei group (Lactobacillus paracasei LPC12) and an experimental group (Lactobacillus paracasei YM2024 of the present invention), and the four groups had the same initial treatment conditions. A three-stage continuous culture intestinal model system was adopted. The three-stage continuous culture model of the human colon consisted of three fermenters, simulating the proximal (V1, 280 mL), transverse (V2, 300 mL) and distal colon (V3, 320 mL). The three fermenters in series were maintained at 37°C, the pH values ​​were maintained at 5.5 (V1), 6.2 (V2) and 6.8 (V3), and anaerobic conditions were introduced by continuous N2. V1 was connected to the intestinal model culture medium (CMGM) through a peristaltic pump. Fresh healthy human fecal samples were collected and stored in an anaerobic cabinet (10% H2, 10% CO2, 80% N2), and a 1:5 (w / w) fecal dilution in anaerobic PBS (0.1 mol / LPBS, pH 7.4) was prepared within a maximum of 15 min after collection. Each stage of the colon model was inoculated with 100 mL of fecal slurry. The total system transit time was set to 48 h based on the average retention time of healthy individuals. After inoculation, the colon model was run as a batch culture for 24 h to stabilize the bacterial population before the start of medium injection. After 24 h, the system was run for 8 full capacity turnovers to achieve steady state. After the positive control group, the commercially available Lactobacillus paracasei group and the experimental group were stabilized, the CMGM medium with pesticides added (80 mg / L dimethoate, 100 mg / L chlorpyrifos, and 50 mg / L glufosinate) was pumped in through a peristaltic pump, and the blank group was pumped in with CMGM medium without dimethoate, chlorpyrifos and glufosinate, and the culture was continued for 24 h until the steady state was reached for 2 h. Considering the operating volume (900 mL) and retention time (48 h) of the colon model system, the experimental group and the commercially available Lactobacillus paracasei group added 1% (w / v) of the live bacteria freeze-dried powder of Lactobacillus paracasei LPC12 and the live bacteria freeze-dried powder of Lactobacillus paracasei YM2024 to V1 every day (the preparation methods of the live bacteria freeze-dried powders of the two groups were the same as those in Example 3, and the live bacteria counts were both 1.1×10 11CFU / g), and then eight volume turnovers were performed to reach a steady state for 3 h, and then the content of dimethoate, chlorpyrifos and glufosinate in the inoculated system was detected by sampling for three consecutive days. The pesticide content was detected by gas chromatography, and the chromatographic conditions were: the carrier gas was high-purity nitrogen, with a flow rate of 10 mL / min; the fuel gas was high-purity H2, with a flow rate of 75 mL / min; the auxiliary gas was air, with a flow rate of 100 mL / min. The injection port temperature was 200℃, the detector temperature was 250℃, the initial column box temperature was 90℃, retained for 1 min, increased to 260℃ at 10℃ / min, and retained for 3 min. The injection mode was splitless injection, and the septum purge was 3 mL / min. A DB-1701 medium-polarity capillary column, FPD detector, injection volume of 1.0 μL, qualitative analysis by retention time, and quantitative analysis by peak area.

[0052] The mean and variance of the sampling tests for three consecutive days are shown in Table 3.

[0053] Table 3 Degradation effect ( ±s)

[0054] In addition, the PMA-qPCR method was used to detect the changes in the number of live Lactobacillus paracasei in the excretion fluid of the experimental group and the control group to determine the colonization ability. The results showed that the strain could still be detected after the addition of the strain to the system was stopped, which indirectly indicated that the Lactobacillus paracasei YM2024 strain could colonize in the intestinal environment. At the same time, the test results showed that the Lactobacillus paracasei YM2024 strain could survive in the intestinal environment for more than one week.

[0055] From the above experimental results, it can be seen that Lactobacillus paracasei YM2024 can not only adsorb pesticides under in vitro conditions, but also promote the degradation of pesticides in an in vitro intestinal fermentation simulation system, and has the potential to colonize, survive for a long time and continuously degrade pesticide residues in the human intestine. At the same time, Lactobacillus paracasei YM2024 has excellent adsorption and degradation effects on mixed pesticides containing dimethoate, chlorpyrifos and glufosinate ammonium, which is more in line with the situation that multiple pesticides may remain in fruits and vegetables in actual applications.

[0056] Example 5 The present embodiment provides a bacterial community YM-Clean probiotic powder with the ability to degrade pesticide residues, and the preparation method thereof is as follows: after the seed liquid of Lactobacillus paracasei YM2024 strain and Bifidobacterium animalis lactis subspecies BAL-28 strain are mixed in a volume ratio of 3:2, 3% inoculum amount is added to the culture medium for fermentation culture, and the culture conditions are: 37°C, 12 hours; after the fermentation is completed, centrifuge at 6000r / min for 30min to obtain bacterial mud, mix the bacterial mud with a freeze-drying protective agent evenly, freeze-dry, and then grind to obtain YM-Clean probiotic powder (the number of viable bacteria is 1.1×1011 CFU / g).

[0057] Preparation method of culture medium: mix 40g glucose, 4g soy peptone, 3g yeast extract powder, 2g diamine hydrogen citrate, 6g anhydrous sodium acetate, 3g dipotassium hydrogen phosphate, 1g isomaltooligosaccharide, 3g starch and other food-grade materials, add 1000g pure water and mix until no particles are visible to the naked eye, adjust the pH to 5.0-6.8 after mixing the materials, and sterilize at 117.5-118.5℃ for 20min to obtain the culture medium.

[0058] Preparation method of freeze-dried protective agent: 100g starch, 20g glucose, 60g maltodextrin, 30g sucrose, 10g lactose, 50g skimmed milk powder and other food raw materials are mixed evenly, 1000g pure water is added to dissolve until no particles are visible to the naked eye, the pH is adjusted to 5.0-6.8 after the materials are dissolved, and sterilized at 117.5-118.5℃ for 20min. After sterilization, the pH is adjusted to 6.0-7.3 to obtain the freeze-dried protective agent.

[0059] Example 6 This example provides the adsorption and degradation effects of the YM-Clean probiotic powder on organophosphorus pesticides prepared in Example 5. This experiment was conducted simultaneously with the adsorption and degradation experiments in Example 4, and the blank control and positive control were the same as those in Example 4.

[0060] 1. Adsorption effect of YM-Clean probiotic powder on organophosphorus pesticides YM-Clean probiotic powder was prepared into 10 7 cfu / mL and 10 9 cfu / mL of live bacterial suspension. Take the live bacterial suspension and prepare the inactivated bacterial suspension in a water bath at 80°C for 30 min. Add the live bacterial suspension and the inactivated bacterial suspension to the solution of dimethoate (3 mg / L), chlorpyrifos (3 mg / L), and glufosinate (3 mg / L), respectively, incubate at 37°C for 4 h, centrifuge (12000 rpm / min) for 3 min, collect the supernatant, and detect by gas chromatography. The chromatographic conditions are the same as those in Example 4. Repeat the experiment 3 times.

[0061] The results are shown in Table 4.

[0062] Table 4 Adsorption effect of YM-Clean probiotic powder on organophosphorus pesticides

[0063] Adsorption rate calculation formula: Adsorption rate (%) = (pesticide concentration before adding bacterial suspension - pesticide concentration after adding bacterial suspension) ÷ pesticide concentration before adding bacterial suspension × 100%.

[0064] As shown in Table 4, the live bacteria and inactivated bacteria of YM-Clean probiotic powder have good adsorption effects on dimethoate, chlorpyrifos and glufosinate. 9 cfu / mL), the adsorption effect of live bacteria of YM-Clean probiotic powder on dimethoate, chlorpyrifos and glufosinate was significantly better than that of Lactobacillus paracasei YM2024 and commercial Lactobacillus paracasei. The adsorption effect of inactivated bacteria on dimethoate was significantly better than that of commercial Lactobacillus paracasei, and the adsorption effect on chlorpyrifos and glufosinate was better than that of Lactobacillus paracasei YM2024 and commercial Lactobacillus paracasei. At a lower concentration (1.0x10 7 cfu / mL), the adsorption effects of live and inactivated bacteria of YM-Clean probiotic powder on dimethoate, chlorpyrifos and glufosinate were significantly better than those of Lactobacillus paracasei YM2024 and commercially available Lactobacillus paracasei.

[0065] 2. Degradation effect of YM-Clean probiotic powder on organophosphorus pesticides The YM-Clean probiotic powder prepared in Example 5 was added to V1 of the three-stage continuous intestinal culture model system at 1% (w / v) every day, and the degradation effect of organophosphorus pesticides was investigated according to the method of Example 4. The content of dimethoate, chlorpyrifos and glufosinate in the system after inoculation was sampled and detected for three consecutive days. The average value and variance of the three consecutive days of sampling and detection are shown in Table 5.

[0066] Table 5 Degradation effect of YM-Clean probiotic powder on organophosphorus pesticides ( ±s)

[0067] In addition, the PMA-qPCR method was used to detect the changes in the number of live bacteria of the experimental group Lactobacillus paracasei YM2024 strain and Bifidobacterium animalis subspecies lactis BAL-28 to determine the colonization ability. The results showed that the strains could still be detected after the addition of YM-Clean probiotic powder was stopped in the system, which indirectly indicated that the strains of YM-Clean probiotic powder could colonize in the intestinal environment. At the same time, the test results showed that the strains of YM-Clean probiotic powder could survive in the intestinal environment for more than one week.

[0068] From the above experimental results, it can be seen that YM-Clean probiotic powder can also adsorb pesticides under in vitro conditions, and can promote the degradation of pesticides in an in vitro intestinal fermentation simulation system, and has the potential to colonize in the human intestine, survive for a long time, and continuously degrade pesticide residues. Compared with the YM2024 strain of Lactobacillus paracasei, YM-Clean probiotic powder has a better adsorption and degradation effect on mixed pesticides containing dimethoate, chlorpyrifos, and glufosinate, and is more suitable for treating fruits and vegetables with multiple pesticide residues.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A strain of Lactobacillus paracasei YM2024, characterized in that Its taxonomic name is Lactobacillus paracasei ( Lacticaseibacillus paracasei ), deposited in the General Microbiology Center of China Microorganism Culture Collection on April 22, 2024, with the deposit number CGMCC No. 29770; the deposit address is Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing.

2. the application of Lactobacillus paracasei YM2024 bacterial strain described in claim 1 in reducing pesticide residues.

3. application of the described Lactobacillus paracasei YM2024 bacterial strain of claim 1 in pesticide residues in absorption liquid.

4. The use according to claim 3, characterized in that: The application method specifically comprises the following operations: adding live bacteria and / or inactivated bacteria of the Lactobacillus paracasei YM2024 strain to the liquid to be treated, maintaining the liquid at 35-39° C. for at least 4 hours, and separating the bacteria; and / or The pesticide is an organophosphorus pesticide; and / or The concentration of the live bacteria or inactivated bacteria in the liquid to be treated is 10 7 cfu / mL~10 9 cfu / mL.

5. The use according to claim 3 or 4, characterized in that: The pesticide includes at least one of dimethoate, chlorpyrifos and glufosinate-ammonium.

6. Application of the described Lactobacillus paracasei YM2024 bacterial strain of claim 1 in degrading pesticides.

7. The use according to claim 6, characterized in that: The application is the application of degrading pesticide residues in the intestine; and / or The pesticide is an organophosphorus pesticide.

8. The use according to claim 6 or 7, characterized in that: The pesticide includes at least one of dimethoate, chlorpyrifos and glufosinate-ammonium.

9. A probiotic powder, characterized in that: The method is prepared from the Lactobacillus paracasei YM2024 strain according to claim 1.

10. A bacterial community YM-Clean capable of degrading pesticide residues, characterized in that: The method comprises the Lactobacillus paracasei YM2024 described in claim 1 and at least one other strain capable of degrading pesticide residues.

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