Serratia marcescens WF01 for degrading pesticide and application of serratia marcescens WF01

Abstract

The invention relates to the technical field of agricultural microorganisms, in particular to serratia marcescens WF01 for degrading pesticides and application of the serratia marcescens WF01. The serratia marcescens WF01 is preserved in China General Microbiological Culture Collection Center (CGMCC) on April 17, 2024, and the preservation number is CGMCC NO.30368. The serratia marcescens WF01 is induced by beta-cypermethrin to obtain a high-yield prodigiosin strain, and the high-yield prodigiosin strain can be used for degrading pesticides. The strain has relatively strong IAA and siderophore production and nitrogen fixation activity, and growth promoting properties of decomposing organic phosphorus, decomposing inorganic phosphorus and the like, has wide pyrethroid pesticide tolerance, and particularly has a very high degradation rate on beta-cypermethrin remained in pepper leaves and soil; the strain can be rapidly and effectively colonized in crop root systems and enter plant bodies, and has very wide application prospects in degradation of pyrethroid pesticides and prevention and control of tomato brown crinkled fruit viruses.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural microorganisms, and specifically relates to Serratia marcescens WF01 for degrading pesticides and its application. Background Art

[0002] With the banning of traditional pesticides such as organochlorines and organophosphates, which are highly toxic and have slow degradation, pyrethroid insecticides are used to control agricultural and forest pests and sanitary pests due to their broad-spectrum insecticidal activity, low residue, high efficiency (fast knockdown speed), and strong activity. They have become one of the most widely used pesticides in China today. With the increase in their usage, the residues of pyrethroid pesticides in the environment are continuously accumulating, causing pollution to the ecological environment and directly affecting the quality of agricultural products and food safety.

[0003] Pyrethroid insecticides are a class of insecticides artificially synthesized by mimicking the chemical structure of natural pyrethrins, mainly composed of cypermethrin, beta-cypermethrin, deltamethrin, bifenthrin, cyfluthrin, lambda-cyhalothrin, fenpropathrin, fenvalerate, etc. As of November 19, 2024, there are a total of 6,709 pyrethroid insecticide products with valid registration in China, involving 42 common varieties, among which lambda-cyhalothrin products account for 13.54% of the total number of pyrethroid insecticides.

[0004] After the use of pyrethroid insecticides, they will remain in the soil, water, and air, causing long-term effects on the environment and ecosystem. These chemicals may enter other organisms through the food chain, leading to bioaccumulation and ultimately disrupting the ecological balance. In addition, they may also contaminate groundwater and have toxic effects on aquatic organisms. Therefore, it is urgent to eliminate the impact on the ecological environment caused by the residues. For example, cypermethrin has stomach poisoning and contact killing effects. Although it is safe for crops, it is moderately toxic to humans and livestock and highly toxic to aquatic organisms, bees, and silkworms.

[0005] Currently, the main methods for solving pesticide residues in the ecological environment include banning, physical and chemical methods, and bioremediation methods, etc. Among them, physical and chemical methods are costly, have large side effects, are prone to secondary pollution, and the elimination is not thorough; bioremediation methods have the advantages of high efficiency, safety, low cost, no secondary pollution, and wide application range, mainly including plant and animal remediation, microbial remediation, etc. Microbial degradation is an important means to eliminate pesticide pollution. It has the advantages of low cost, high efficiency, and no secondary pollution, and is generally considered the most effective and feasible method. However, the current microbial strain resources for degrading pyrethroid insecticides are insufficient, which restricts the practical application of this remediation technology.

[0006] Tomato brown rugose fruit virus (ToBRFV), a newly discovered RNA virus, is extremely harmful and highly transmissible. It mainly infects crops such as tomatoes, peppers, and tobacco, and can be transmitted through seeds and fruits. In severe cases of disease, the economic loss can reach up to 100%. Since its discovery in 2014, it has rapidly spread to more than 30 countries in Europe, the Americas, and Asia. In China, ToBRFV was first detected infecting tomatoes in Shandong in 2019. Subsequently, the virus was successively discovered in Shaanxi, Jiangsu, Yunnan, Hebei, Henan, Anhui, Guangdong, Liaoning and other places, causing extremely serious harm. In April 2021, ToBRFV was listed in the Catalogue of Quarantine Pests of Imported Plants of the People's Republic of China. Due to the short research time on ToBRFV, current prevention and control technology development involves aspects such as the development of detection methods, the excavation of resistance genes, and the breeding of resistant varieties, while the prevention and control technology using microbial induction of ToBRFV resistance has not been reported.

[0007] Therefore, it is of great significance to breed a microorganism that can not only degrade pyrethroid insecticides but also control tomato brown rugose fruit virus, and it has broad application prospects. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide Serratia marcescens WF01 for degrading pesticides, which can not only degrade pyrethroid insecticides but also control tomato brown rugose fruit virus, and its application.

[0009] To solve the above technical problems, the technical solution of the present invention is: Provide Serratia marcescens WF01 for degrading pesticides. The Serratia marcescens WF01 was deposited at the General Microbiological Center of the China Committee for Culture Collection of Microorganisms on April 17, 2024, with the deposit number CGMCC NO.30368 and the deposit address at Beichen West Road, Chaoyang District, Beijing, and the taxonomic name is Serratia marcescens Serratia marcescens .

[0010] Provide an antibacterial agent induced by tomato brown rugose fruit virus, which contains the Serratia marcescens WF01 for degrading pesticides.

[0011] As a preferred technical solution, the antibacterial agent induced by tomato brown rugose fruit virus has the effect of degrading pyrethroid insecticides.

[0012] As a preferred technical solution, the active ingredient of the pyrethroid insecticide is beta-cypermethrin or lambda-cyhalothrin or cypermethrin.

[0013] As a preferred technical solution, the beta-cypermethrin is the beta-cypermethrin remaining in the pepper planting soil and / or in the pepper plant.

[0014] As a preferred technical solution, the tomato brown rugose fruit virus inducing antibacterial agent is used during the growth period of pepper and is applied by root irrigation.

[0015] Provided is a method for preparing the tomato brown rugose fruit virus inducing antibacterial agent. Streak the Serratia marcescens WF01 onto a solid medium with beta-cypermethrin as the sole carbon source, and culture it in an inverted position at 32 °C for 36 - 40 h; pick a bright red single colony and inoculate it into a liquid medium with beta-cypermethrin as the sole carbon source, and culture it with shaking at 32 °C and 185 r / min for 48 h to obtain the seed liquid of Serratia marcescens WF01; inoculate the seed liquid into a liquid medium without any carbon source at a volume ratio of 10%, culture it with shaking at 28 °C and 185 r / min for 3 - 5 h, then add yeast extract, and continue to culture it with shaking at 28 °C and 200 r / min for 48 h to obtain the tomato brown rugose fruit virus inducing antibacterial agent, and the tomato brown rugose fruit virus inducing antibacterial agent is a deep red fermentation broth of Serratia marcescens WF01.

[0016] As a preferred technical solution, the content of prodigiosin in the fermentation broth of Serratia marcescens WF01 reaches 13.5 - 17.2 g / L, and the effective viable count is 0.5×10 9 cfu / mL - 1.0×10 9 cfu / mL.

[0017] As a preferred technical solution, the tomato brown rugose fruit virus inducing antibacterial agent can improve the ability of Serratia marcescens WF01 in preventing and controlling tomato brown rugose fruit virus disease.

[0018] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows: (1) The Serratia marcescens WF01 of the present invention is a high-yield prodigiosin strain obtained by induction with beta-cypermethrin from an initial strain, and the initial strain is isolated from the wheat leaves in an environment where beta-cypermethrin pesticide has been used for a long time. After induction, the prodigiosin yield reaches 17.2 g / L from the initial 9.5 g / L, and the yield increases by 81.1%; (2) Among the KEGG functional classifications of the whole genome of this strain, there are 16 related to xenobiotic metabolism and degradation, and 41 genes regulating xenobiotic biological metabolism and degradation; (3) This strain has a strong IAA-producing ability, and the IAA production can reach 56.18 mg / L; (4) This strain has a strong ability to produce siderophores; (5)This strain has strong abilities such as nitrogen fixation, decomposition of organic phosphorus, and decomposition of inorganic phosphorus; (6)This strain has a wide tolerance to pyrethroid pesticides. In particular, it has a good degradation effect on beta-cypermethrin. Under the condition of indoor soil cultivation, the degradation rate of beta-cypermethrin can reach 75.28%; this strain can quickly colonize on the crop roots and enter the plant body. The degradation rate of residual beta-cypermethrin in pepper leaves can reach 76.80%, and the degradation rate of residual beta-cypermethrin in pepper rhizosphere soil can reach 78.95%. It has broad application prospects in the degradation of residual pyrethroid pesticides; (7)This strain has a relatively significant control effect on tomato brown rugose fruit virus on field pepper crops. Description of the Drawings

[0019] The following drawings are only intended to illustrate and explain the present invention schematically and do not limit the scope of the present invention. Among them: Figure 1 is the colony morphology diagram of Serratia marcescens WF01 for degrading pesticides of the present invention on NA solid medium; Figure 2 is the phylogenetic tree of Serratia marcescens WF01 for degrading pesticides of the present invention; Figure 3 is the effect diagram of Serratia marcescens WF01 for degrading pesticides of the present invention in decomposing organic phosphorus; Figure 4 is the effect diagram of Serratia marcescens WF01 for degrading pesticides of the present invention in producing siderophores; Figure 5 is the diagram of the residual amount of beta-cypermethrin of Serratia marcescens WF01 for degrading pesticides of the present invention at different times; Figure 6 is the genome circle diagram of Serratia marcescens WF01 for degrading pesticides of the present invention; Figure 7 is the annotation diagram of the KEGG function analysis result of Serratia marcescens WF01 for degrading pesticides of the present invention. Detailed Embodiments

[0020] In order to make the objectives and technical solutions of the present invention clearer and easier to understand, the present invention will be further described in detail below. The experimental methods described in the following embodiments are all conventional methods unless otherwise specified; for those not specifying specific techniques or conditions in the embodiments, they shall be carried out according to the techniques or conditions described in the literature in this field or according to the product specifications; the reagents and materials, unless otherwise specified, can be obtained from commercial channels.

[0021] The experimental methods used in the following embodiments are all conventional methods unless otherwise specified.

[0022] Materials, reagents, etc. used in the following examples can be obtained from commercial sources without special instructions.

[0023] All kinds of culture media involved in the following examples are standard culture media commonly used in the art.

[0024] Example 1: Obtaining Serratia marcescens WF01 with High Yield of Prodigiosin Induced by Beta-cypermethrin 1. Screening of the Initial Strain of Serratia marcescens WF01 The initial strain of Serratia marcescens WF01 in this example was isolated from the leaves of wheat plants in saline-alkali land in Weifang, Shandong, where beta-cypermethrin has been used for a long time. The screening method is as follows: Select healthy and robust wheat plants, cut off the above-ground parts of the wheat plants with scissors, first rinse with tap water to remove surface attachments such as soil, soak the wheat plant leaves in 3% sodium hypochlorite in a laminar flow bench for 8 - 10 min, rinse with sterile water 4 - 5 times, then soak in 75% alcohol for 4 - 5 min, after rinsing with sterile water 4 - 5 times, dry the surface moisture of the leaves with sterile filter paper, put the leaves into a sterilized mortar, add 5 - 10 ml of 1×PBS buffer (sterile) and grind to obtain the sample stock solution. Pipette 100 μL of the sample stock solution into a 250 mL Erlenmeyer flask containing 50 mL of culture medium (beta-cypermethrin 0.1 g / L, dipotassium hydrogen phosphate 5.8 g / L, ammonium sulfate 2.0 g / L, potassium dihydrogen phosphate 1.5 g / L, magnesium sulfate heptahydrate 0.2 g / L, sodium chloride 1.0 g / L, distilled water 1 L, pH 7.0 - 7.2), shake and culture at 30 °C and 185 r / min for 48 h to obtain an enriched culture solution. Perform gradient dilution on the enriched culture solution, and spread 100 μL of the dilution solutions with dilution factors of 10 -5 、10 -6 、10 -7 evenly on NA solid medium (beef extract 5 g / L, peptone 10 g / L, sodium chloride 5 g / L, agar 20 g / L, pH 7.0 - 7.2) and incubate in an inverted position at 28 °C for 48 h, then pick out the grown red or pink single colonies (dominant colonies) for purification.

[0025] 2. Identification of the Initial Strain of Serratia marcescens WF01 Perform morphological identification on the isolated strain. The results show that after culturing the strain on NA solid medium at 28 °C for 24 h, dark red colonies (as Figure 1 shown) are formed, with a diameter of 2 - 4 mm. The colony surface is smooth and moist, the edge is neat, protruding and opaque. The bacteria are Gram-negative, with a morphology close to spherical or short rod-shaped, 0.4 - 0.5 μm wide and 0.4 - 0.8 μm long.

[0026] The isolated strain was identified by molecular biology, and the results were as follows: Figure 2 As shown, the universal bacterial primers 27f and 1492r were used for PCR amplification of the 16S rDNA gene. The amplification product was sent to Beijing New Era Zhonghe Technology Co., Ltd. for sequencing, and then the sequencing results were compared and analyzed on the NCBI and EzBio Cloud websites. After identification, the strain was Serratia marcescens, which was the initial strain of Serratia marcescens WF01.

[0027] 3. Serratia marcescens WF01 with high production of prodigiosin induced by beta-cypermethrin The initial strain of Serratia marcescens WF01 was gradually induced with different concentrations of beta-cypermethrin to make the strain's tolerance to beta-cypermethrin reach 1.5 g / L.

[0028] The induction concentrations of beta-cypermethrin were 0.2 g / L, 0.4 g / L, 0.5 g / L, 0.8 g / L, 1.0 g / L, and 1.5 g / L respectively. The initial strain of Serratia marcescens WF01 was inoculated into a basal salt liquid medium (5.8 g / L dipotassium hydrogen phosphate, 2.0 g / L ammonium sulfate, 1.5 g / L potassium dihydrogen phosphate, 0.2 g / L magnesium sulfate heptahydrate, 1.0 g / L sodium chloride, 1 L distilled water, pH 7.0 - 7.2) with beta-cypermethrin as the sole carbon source, and cultured at 28 °C and 180 r / min for 3 d. Then, 100 μl was taken and evenly spread on a basal salt solid medium (5.8 g / L dipotassium hydrogen phosphate, 2.0 g / L ammonium sulfate, 1.5 g / L potassium dihydrogen phosphate, 0.2 g / L magnesium sulfate heptahydrate, 1.0 g / L sodium chloride, 20 g / L agar, 1 L distilled water, pH 7.0 - 7.2) containing the same concentration of beta-cypermethrin. After normal growth, it was transferred to the next lower concentration for induction until a strain that rapidly formed bright red colonies on a solid medium with a beta-cypermethrin concentration of 1.5 g / L was obtained. This strain was named Serratia marcescens WF01. At the same time, the initial strain and the strains obtained after each induction were inoculated into a liquid fermentation medium (5.5 g / L sucrose, 5 g / L sodium citrate, 8 g / L ammonium chloride, 0.5 g / L dipotassium hydrogen phosphate, 1 g / L magnesium sulfate heptahydrate, 0.04 g / L ferric chloride heptahydrate, 0.15 g / L calcium chloride anhydrous, pH 7.0 - 7.2) and cultured at 28 °C and 180 r / min for 2 d to obtain the liquid fermentation broths of the initial strain and the induced strains; referring to the literature "Optimization of Fermentation Conditions for the Production of Prodigiosin by a New Marine Serratia marcescens Strain", the prodigiosin in the liquid fermentation broths of the initial strain and the induced strains was extracted and detected by a normal-phase liquid chromatography-mass spectrometry (HPLC-APCI-MS; Agilent 1200 series).

[0029] After stepwise induction with beta-cypermethrin, the prodigiosin yield of Serratia marcescens WF01 increased from 9.5 g / L of the initial strain to 17.2 g / L.

[0030] The Serratia marcescens WF01 obtained by induction with beta-cypermethrin was deposited at the China General Microbiological Culture Collection Center (CGMCC) on April 17, 2024. The deposit number is CGMCC NO. 30368, and the deposit address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing.

[0031] Example 2: Determination of the growth-promoting performance of Serratia marcescens WF01 In this example, the growth-promoting performances of Serratia marcescens WF01, such as the secretion ability of auxin IAA, the ability to produce siderophores, and nitrogen fixation activity, were determined.

[0032] The test methods are as follows: 1. Determination of siderophore production: Inoculate Serratia marcescens WF01 onto the CAS detection solid medium (CAS detection medium: chrome azurol 60.5 mg, cetyltrimethylammonium bromide 72.9 mg, ferric chloride 2.645 mg, sodium dihydrogen phosphate 295.25 mg, disodium hydrogen phosphate dodecahydrate 1213.5 mg, ammonium chloride 125 mg, potassium dihydrogen phosphate 37.5 mg, sodium chloride 62.5 mg, agar 9 g, pH 6.8, made up to 1 L with distilled water, pH 6.8), and culture at 30 °C for 6 d. If a yellow-green halo appears, it indicates siderophore production, and the larger the halo, the stronger the siderophore production ability.

[0033] 2. Determination of nitrogen fixation activity: Inoculate Serratia marcescens WF01 onto the Ashby nitrogen-free solid medium (dipotassium hydrogen phosphate 0.2 g, magnesium sulfate heptahydrate 0.2 g, sodium chloride 0.2 g, calcium carbonate 5.0 g, mannitol 10.0 g, calcium sulfate 0.1 g, distilled water 1 L, agar 15 g, pH 7.0), and culture at 30 °C for 70 - 72 h, then observe the colony growth. If the strain can grow on the Ashby nitrogen-free solid medium, it represents that the strain has nitrogen fixation activity, and the nitrogen fixation activity size can be judged according to the colony growth diameter.

[0034] Determination of the ability to decompose organic phosphorus and inorganic phosphorus: Inoculate Serratia marcescens WF01 onto the Meng Jinna inorganic phosphorus solid medium ((NH 4 ) 2 SO 4 0.5 g, MgSO 4 ·7H2O 0.5 g, NaCl 50 g, Ca 3 (PO 4 ) 210.0 g, CaCO 3 2.5 g, 2.0 g of glucose, MnSO 4 0.02 g, FeSO 4 0.02 g, 20.0 g of agar, pH 7.2, 1000 mL of distilled water) and lecithin organic phosphorus solid medium (10.0 g of glucose, (NH 4 ) 2 SO 4 0.5 g, 0.3 g of NaCl, MgSO 4 ·7H 2 O 0.3 g, MnSO 4 0.02 g, 0.3 g of KCl, FeSO 4 0.03 g, 2.0 g of lecithin, 15.0 g of agar, pH 7.2, 1000 mL of distilled water), and cultured in an inverted position at 28 °C for 7 - 10 d. Observe whether a transparent phosphorus-dissolving circle appears in the strain, and measure the diameter D of the phosphorus-dissolving circle and the diameter d of the colony. Qualitatively judge the ability of the strain to decompose organic phosphorus and inorganic phosphorus by the ratio (D / d).

[0035] 4. Determination of the ability to secrete auxin IAA: Determine the ability to produce indole acetic acid IAA by the Salkowski method; specifically, inoculate Serratia marcescens WF01 into King's B liquid medium containing 500 mg / L tryptophan, shake culture at 28 °C and 180 r / min for 70 - 72 h, take 2 mL of the bacterial suspension, centrifuge at 10000 r / min for 15 min, take the supernatant and add Salkowski reagent (add 2 mL of Salkowski reagent to every 1 mL of supernatant), develop color in the dark at room temperature for 30 min, and measure the OD530 value. Use the blank medium as a control, and use the OD530 value corresponding to pure IAA as a standard curve to calculate the IAA content (mg / L) in the culture solution.

[0036] Table 1 Growth-promoting performance of Serratia marcescens WF01

[0037] Note: + indicates general performance; ++ indicates medium performance; +++ indicates strong performance.

[0038] As Figure 3 、 Figure 4 shown, Serratia marcescens WF01 has strong nitrogen-fixing, organic phosphorus-decomposing, inorganic phosphorus-decomposing, and siderophore-producing abilities, and its IAA production can reach 56.18 mg / L; thus indicating that: Serratia marcescens WF01 of the present invention has strong potential for promoting plant growth.

[0039] Example 3: Preparation of Sample 1 of Tomato Brown Rugose Fruit Virus Inducing Bacteriostatic Agent Streak Serratia marcescens WF01 onto a solid medium with beta-cypermethrin as the sole carbon source (beta-cypermethrin 1.5 g / L, dipotassium hydrogen phosphate 5.8 g / L, ammonium sulfate 2.0 g / L, potassium dihydrogen phosphate 1.5 g / L, magnesium sulfate heptahydrate 0.2 g / L, sodium chloride 1.0 g / L, agar 18 g / L, distilled water 1 L, pH 7.0 - 7.2), and incubate it in an inverted position at 32 °C for 36 h; pick a bright red single colony and inoculate it into a liquid fermentation medium with beta-cypermethrin as the sole carbon source (K 2 HPO 4 5.8 g / L, (NH 4 ) 2 SO 4 2.0 g / L, KH 2 PO 4 1.5 g / L, MgSO 4 ·7H 2 O 0.2 g / L, NaC1 1.0 g / L, distilled water 1 L, pH 7.0 - 7.2), and incubate it on a shaker at 32 °C and 185 r / min for 48 h to obtain a seed solution of Serratia marcescens WF01; inoculate the seed solution into a liquid fermentation medium without any carbon source at a volume ratio of 10% (NH 4 Cl 8 g / L, K 2 HPO 4 0.5 g / L, MgSO 4 ·7H 2 O 1 g / L, FeCl 3 ·7H 2 O0.04 g / L, anhydrous CaCl 2 0.15 g / L, pH 7.0 - 7.2), incubate it on a shaker at 28 °C and 185 r / min for 3 h, then add yeast extract (final concentration 3 g / L) to the fermentation broth, and continue to incubate it on a shaker at 28 °C and 200 r / min for 48 h to obtain Sample 1 of Tomato Brown Rugose Fruit Virus Inducing Bacteriostatic Agent. Sample 1 of Tomato Brown Rugose Fruit Virus Inducing Bacteriostatic Agent is a deep red fermentation broth of Serratia marcescens WF01.

[0040] Using the method for determining the effective viable count of agricultural microbial inoculants in GB20287-2006, the effective viable count of Serratia marcescens in Sample 1 of this Tomato Brown Rugose Fruit Virus Inducing Bacteriostatic Agent was measured to be 0.5×10 9cfu / mL; In the reference "Optimization of Fermentation Conditions for the Production of Prodigiosin by a New Marine Serratia marcescens Strain", prodigiosin in the tomato brown rugose fruit virus-induced antibacterial agent sample 1 was extracted and detected by a normal-phase liquid chromatography-mass spectrometry (HPLC-APCI-MS; Agilent 1200 series). The yield of prodigiosin in the tomato brown rugose fruit virus-induced antibacterial agent sample 1 was 13.5 g / L.

[0041] Example 4: Preparation of tomato brown rugose fruit virus-induced antibacterial agent sample 2 Streak Serratia marcescens WF01 onto a solid medium with beta-cypermethrin as the sole carbon source (beta-cypermethrin 1.5 g / L, dipotassium hydrogen phosphate 5.8 g / L, ammonium sulfate 2.0 g / L, potassium dihydrogen phosphate 1.5 g / L, magnesium sulfate heptahydrate 0.2 g / L, sodium chloride 1.0 g / L, agar 18 g / L, distilled water 1 L, pH 7.0 - 7.2), and incubate it inverted at 32 °C for 38 h; pick a bright red single colony and inoculate it into a liquid fermentation medium with beta-cypermethrin as the sole carbon source (K 2 HPO 4 5.8 g / L, (NH 4 ) 2 SO 4 2.0 g / L, KH 2 PO 4 1.5 g / L, MgSO 4 ·7H 2 O 0.2 g / L, NaC1 1.0 g / L, distilled water 1 L, pH 7.0 - 7.2), and incubate it with shaking at 32 °C and 185 r / min for 48 h to obtain the Serratia marcescens WF01 seed liquid; inoculate the seed liquid into a liquid fermentation medium without any carbon source at a volume ratio of 10% (NH 4 Cl 8 g / L, K 2 HPO 4 0.5 g / L, MgSO 4 ·7H 2 O 1 g / L, FeCl 3 ·7H 2 O 0.04 g / L, anhydrous CaCl 2 0.15 g / L, pH 7.0 - 7.2), incubate it with shaking at 28 °C and 185 r / min for 5 h, then add yeast extract (final concentration 3 g / L) to the fermentation broth, and continue to incubate it with shaking at 28 °C and 200 r / min for 48 h to obtain the tomato brown rugose fruit virus-induced antibacterial agent sample 2, which is a dark red fermentation broth of Serratia marcescens WF01.

[0042] Using the method for determining the effective viable count in GB 20287-2006 Agricultural microbial inoculum, the effective viable count of Serratia marcescens in the tomato brown rugose fruit virus-induced antibacterial agent sample two is 0.8×10 9 cfu / mL; referring to the reference "Optimization of the fermentation conditions for the production of prodigiosin by a new marine Serratia marcescens strain", the prodigiosin in the tomato brown rugose fruit virus-induced antibacterial agent sample two was extracted and detected by a normal-phase liquid chromatography-mass spectrometry (HPLC-APCI-MS; Agilent 1200 series). The yield of prodigiosin in the tomato brown rugose fruit virus-induced antibacterial agent sample two is 16.0 g / L.

[0043] Example 5: Preparation of tomato brown rugose fruit virus-induced antibacterial agent sample three Streak Serratia marcescens WF01 onto a solid medium with beta-cypermethrin as the sole carbon source (beta-cypermethrin 1.5 g / L, dipotassium hydrogen phosphate 5.8 g / L, ammonium sulfate 2.0 g / L, potassium dihydrogen phosphate 1.5 g / L, magnesium sulfate heptahydrate 0.2 g / L, sodium chloride 1.0 g / L, agar 18 g / L, distilled water 1 L, pH 7.0 - 7.2), and incubate it inverted at 32 °C for 40 h; pick a bright red single colony and inoculate it into a liquid fermentation medium with beta-cypermethrin as the sole carbon source (K 2 HPO 4 5.8 g / L, (NH 4 ) 2 SO 4 2.0 g / L, KH 2 PO 4 1.5 g / L, MgSO 4 ·7H 2 O 0.2 g / L, NaC1 1.0 g / L, distilled water 1 L, pH 7.0 - 7.2), and shake-culture it at 32 °C and 185 r / min for 48 h to obtain the Serratia marcescens WF01 seed liquid; inoculate the seed liquid into a liquid fermentation medium without any carbon source at a volume ratio of 10% (NH 4 Cl 8 g / L, K 2 HPO 4 0.5 g / L, MgSO 4 ·7H 2 O 1 g / L, FeCl 3 ·7H 2 O 0.04 g / L, anhydrous CaCl 2In (0.15 g / L, pH 7.0 - 7.2), after shaking cultivation at 28°C and 185 r / min for 4 h, yeast extract (final concentration 3 g / L) was added to the fermentation broth, and then continued to shake cultivate at 28°C and 200 r / min for 48 h to obtain the tomato brown rugose fruit virus-induced antibacterial agent sample three. The tomato brown rugose fruit virus-induced antibacterial agent sample three is the fermentation broth of Serratia marcescens WF01 which is dark red.

[0044] Using the method for determining the effective viable count of agricultural microbial inoculants in GB20287-2006, the effective viable count of Serratia marcescens in this tomato brown rugose fruit virus-induced antibacterial agent sample three is 1.0×10 9 cfu / mL; Referring to the reference "Optimization of Fermentation Conditions for the Production of Prodigiosin by a New Marine Serratia marcescens Strain", the prodigiosin in the tomato brown rugose fruit virus-induced antibacterial agent sample three was extracted. After detection by a normal-phase liquid chromatography-mass spectrometry (HPLC-APCI-MS; Agilent 1200 series), the prodigiosin yield in this tomato brown rugose fruit virus-induced antibacterial agent sample three is 17.2 g / L.

[0045] Example Six: Degradation Effect of Tomato Brown Rugose Fruit Virus-Induced Antibacterial Agent on Beta-Cypermethrin The high-performance liquid chromatography method was used to determine the degradation effect of the tomato brown rugose fruit virus-induced antibacterial agent on beta-cypermethrin. The method is as follows: Accurately weigh 0.05 g of beta-cypermethrin standard product, dissolve it with acetonitrile, and make up the volume to a 10 mL volumetric flask. The final concentration is 5 g / L. Use a high-performance liquid chromatograph (HPLC) to determine and make a standard curve. Add beta-cypermethrin emulsifiable concentrate to the inorganic salt medium (make the final concentration of beta-cypermethrin 0.8 g / L), inoculate 1 mL of the prepared tomato brown rugose fruit virus-induced antibacterial agent sample one, and shake cultivate at 28°C and 180 r / min. Samples were taken at 0, 12 h, and 24 h respectively to determine the content of beta-cypermethrin, with the one without inoculating the tomato brown rugose fruit virus-induced antibacterial agent sample one as the control. Add an equal amount of petroleum ether to 50 mL of the fermentation broth, shake and extract for 1.5 h, transfer it to a separatory funnel, take the lower organic phase, transfer the upper aqueous phase to an Erlenmeyer flask, and extract 3 times. Combine the organic phases, add anhydrous sodium sulfate to remove water, then transfer it to a 250 mL flask, and rotary evaporate to dryness under negative pressure at 56°C. Add petroleum ether to dissolve it in 3 times and make up the volume to 20 mL. HPLC detection: The chromatographic column is Elite C18 column, particle size 5 μm, mobile phase: water + acetonitrile (80:20), flow rate: 1 mL / min, detection wavelength: 235 nm, injection volume: 10 μl, column temperature: 35°C.

[0046] The results are as Figure 5As shown, the residual rate of beta-cypermethrin in the culture medium was 54.62% after 12 h of inoculating Sample 1, showing a significant difference compared with the control without inoculating Sample 1 (P < 0.05). The residual rate of beta-cypermethrin in the culture medium was 10.51% after 24 h of inoculating Sample 1, while the residual rate of the control without inoculating Sample 1 was 81.75%, showing an extremely significant difference (P < 0.01). Serratia marcescens WF01 can use beta-cypermethrin as a carbon source for degradation in the inorganic salt medium.

[0047] Example 7: Determination of the tolerance of Serratia marcescens WF01 to other pyrethroid pesticides The test method of this example is as follows: Determine the tolerance of Serratia marcescens WF01 to 5 pyrethroid pesticides (permethrin, deltamethrin, lambda-cyhalothrin, fenvalerate, bifenthrin) other than beta-cypermethrin: Add different concentrations of permethrin (25% powder), deltamethrin (2.5% powder), lambda-cyhalothrin (10% powder), fenvalerate (20% emulsifiable concentrate), and bifenthrin (5% emulsifiable concentrate) to 50 mL of inorganic salt culture (carbon source-free) medium respectively, and configure the final concentrations to be 50 mg / L, 100 mg / L, 150 mg / L, 200 mg / L, 250 mg / L, 300 mg / L, 350 mg / L, 400 mg / L, 500 mg / L. Then inoculate 1 mL of the prepared Sample 1 of the tomato brown rugose fruit virus inducer, and culture at 28 °C and 180 r / min for 48 h, and observe the tolerance of Serratia marcescens WF01 to 5 pesticides such as permethrin, deltamethrin, lambda-cyhalothrin, fenvalerate, and bifenthrin. Judgment method: Add different concentrations of permethrin, deltamethrin, lambda-cyhalothrin, fenvalerate, and bifenthrin to the inorganic salt medium for culture, and judge whether Serratia marcescens WF01 can tolerate the pyrethroid pesticides at this concentration by observing whether the inoculated Serratia marcescens WF01 grows in it, that is, whether the culture solution becomes turbid.

[0048] Table 2 Tolerance of Serratia marcescens WF01 to other pyrethroid pesticides

[0049] Pyrethroid pesticides at different concentrations were added to the MSM inorganic salt medium. By observing whether the Serratia marcescens WF01 inoculated therein grew, that is, whether the solution became turbid, it was determined whether Serratia marcescens WF01 could tolerate the pyrethroid pesticides at that concentration. The test results showed that Serratia marcescens WF01 could grow and reproduce using the 5 pyrethroid pesticides tested, and the highest tolerance concentration was in the range of 400 - 500 mg / L, having the potential to widely degrade other pyrethroid pesticides.

[0050] Example 8: Gene cluster analysis of Serratia marcescens WF01 This example provides the whole genome sequencing results of Serratia marcescens WF01 and the analysis results of secondary metabolite gene clusters. The specific methods and results are as follows: The whole genome sequencing of this example was completed by Shanghai Bioengineering Co., Ltd. Using the combined sequencing technology of the second-generation Illumina and the third-generation PacBio, the sequencing results were subjected to functional analysis with the NR, Swiss-Prot, Pfam, EggNOG, GO, and KEGG databases.

[0051] As Figure 6 shown, analyzing the sequencing results found that the whole genome of Serratia marcescens WF01 is a circular DNA molecule, assembled into 1 scaffold in total, with a full length of 5089176 bp, a GC content of 59.67%, predicting 4879 coding genes, with a length of 4767972 bp and an average length of 937 bp; among them, the genes related to transcription are the most, and the genes related to amino acid transport and metabolism reach 416, and the genes related to carbohydrate transport and metabolism are 333; 468 genes are for general function prediction, related to the biosynthesis, transport, and catabolism of secondary metabolites, etc.

[0052] The abundances of each functional level of KEGG are as Figure 7 shown. The whole genome of Serratia marcescens WF01 has a total of 2424 genes, which are respectively annotated in five major categories in the KEGG database: cellular processes, metabolism, genetic information processing, organic systems, and environmental information processing; in the secondary functional classification, a total of 174 metabolic pathways are enriched to 29 KEGG functional classifications, and 16 of them are related to xenobiotic metabolism and degradation (see Table 3), including benzoic acid metabolism, aminobenzoate metabolism, dioxin metabolism, ethylbenzene metabolism, and the metabolism of the three-class carcinogen atrazine; among them, there are a total of 41 genes regulating xenobiotic metabolism and degradation in strain WF01. These results indicate that WF01 has strong potential for xenobiotic metabolism and degradation and has great application potential in degrading organic pollutants and other aspects.

[0053] Table 3 Pathways related to xenobiotic metabolism and degradation in Serratia marcescens WF01

[0054] The results of AntiSMASH analysis showed (Table 4) that there were 158 NRPS (non-ribosomal peptide synthetase) genes, indicating stronger stress resistance in harsh environments; there were 32 ribosomally synthesized peptide analog genes, 19 β-lactone genes, 26 prodigiosin genes, and 18 thiopeptide antibiotic genes, which might play a key role in the interaction between plants and microorganisms; there were 19 redox cofactor genes, which played a key role in maintaining intracellular redox homeostasis and had important effects on cell metabolism, growth performance, and biosynthesis ability.

[0055] Table 4 Identification results of secondary metabolite gene clusters of Serratia marcescens WF01

[0056] Experimental Example 1: Colonization performance of different Serratia marcescens strains in pepper plants This example provides a comparative test on the colonization performance of Serratia marcescens WF01 and other existing Serratia marcescens strains (i.e., control strain 1 and control strain 2) in pepper plants. The test method and each treatment are as follows: Control group: sterile water; Treatment 1: Sample 1 of the tomato brown rugose fruit virus-induced antibacterial agent prepared in Example 3 (0.5×10 9 cfu / mL); Treatment 2: A liquid bacterium agent (0.5×10 9 cfu / mL) prepared from control strain 1 (Serratia marcescens CGMCC1.4256, purchased from the China General Microbiological Culture Collection Center) using the liquid fermentation medium of Example 3; Treatment 3: A liquid bacterium agent (0.5×10 9 cfu / mL) prepared from control strain 2 (Serratia marcescens CICC 10370, purchased from the China Center for Industrial Culture Collection of Microorganisms) using the liquid fermentation medium of Example 3; Select plump and healthy pepper seeds (the variety is thread pepper) and soak them in cool water for 24 h; disinfect the pepper seeds under sterile conditions. First, treat them with 75% alcohol for 30 - 60 s, then wash them 3 times with sterile water, then treat them with 3% - 5% NaClO for 8 - 10 min, and finally wash them 8 - 10 times with sterile water; spread the disinfected pepper seeds evenly in a tissue culture bottle containing a basic medium (950 mg of potassium nitrate, 825 mg of ammonium nitrate, 85 mg of potassium dihydrogen phosphate, 185 mg of magnesium sulfate, 220 mg of calcium chloride, 0.83 mg of potassium iodide, 6.2 mg of boric acid, 22.30 mg of manganese sulfate, 8.6 mg of zinc sulfate, 0.25 mg of sodium molybdate, 0.025 mg of copper sulfate, 0.025 mg of cobalt chloride, 37.3 mg of disodium ethylenediaminetetraacetate, 27.8 mg of ferrous sulfate, 100 mg of inositol, 2 mg of glycine, 0.1 mg of thiamine hydrochloride, 0.5 mg of pyridoxine hydrochloride, 0.5 mg of nicotinic acid, 30 g of sucrose, 7 g of agar, made up to 1 L with distilled water), and wait for the seeds to germinate for 6 d to become pepper seedlings.

[0057] Respectively dilute treatment 1 (the effective viable count is 0.5×10 9 cfu / mL), treatment 2 (the effective viable count is 0.5×10 9 cfu / mL), and treatment 3 (the effective viable count is 0.5×10 9 cfu / mL) with sterile water to OD600 = 0.8; centrifuge at 10000 rpm at 4℃ for 10 min, discard the supernatant, collect the bacterial cells, and mix them well with 1 mL of sterile water to obtain a bacterial suspension; under sterile conditions, inoculate the bacterial suspension onto the roots of pepper seedlings respectively. At 12 h, 24 h, and 36 h after inoculation, cut the roots, stems, and leaves of the pepper seedlings treated with each inoculant and the non-inoculated (control group), weigh them and place them in 1.5 mL sterile centrifuge tubes. After surface disinfection in the same way as the pepper seeds; smash them with a sterile glass rod, dilute them to different multiples respectively and spread them evenly on NA solid medium, and count the total number of Serratia marcescens in different parts of the pepper. The colony counting method refers to the method for determining the effective viable count in the agricultural microbial inoculant GB20287 - 2006, and count the counting results of Serratia marcescens after culturing at 28℃ for 24 h.

[0058] Table 5 Colonization performance of different strains of Serratia marcescens in peppers

[0059] The results are shown in Table 5. Serratia marcescens was not detected in the roots, stems, and leaves of the pepper plants in the control group. Serratia marcescens was detected in the roots, stems, and leaves of the plants in Treatment 1 (inoculated with Serratia marcescens WF01). Serratia marcescens could be detected in the roots and stems of the pepper plants 12 h after inoculation, and in the leaves 24 h after inoculation, indicating that this strain could enter the root system in a short time and then colonize in the stems and leaves. Within 36 h after inoculation, Serratia marcescens was only detected in the roots of the plants in Treatment 2 (inoculated with control strain 1), and not in the stems and leaves. Within 36 h after inoculation, Serratia marcescens was not detected in the roots, stems, and leaves of the pepper plants in Treatment 3 (inoculated with control strain 2). The results show that after being inoculated into the pepper root system, Serratia marcescens WF01 can quickly colonize in the pepper root system and then quickly transfer and colonize in the pepper stems and leaves.

[0060] Experimental Example 2: Degradation of beta-cypermethrin by different treatments under indoor soil culture conditions This example provides a comparative experiment on the degradation of beta-cypermethrin by Serratia marcescens WF01 and other existing Serratia marcescens strains (control strain 1, control strain 2) under indoor soil culture conditions. The experimental method and each treatment are as follows: Control group: sterile water; Treatment 1: Sample 1 of the tomato brown rugose fruit virus-induced antibacterial agent prepared in Example 3 (0.5×10 9 cfu / mL); Treatment 2: Liquid bacterium agent (0.5×10 9 cfu / mL) prepared from control strain 1 (Serratia marcescens CGMCC 1.4256, purchased from China General Microbiological Culture Collection Center) using the liquid fermentation medium of Example 3; Treatment 3: Liquid bacterium agent (0.5×10 9 cfu / mL) prepared from control strain 2 (Serratia marcescens CICC 10370, purchased from China National Center for Industrial Culture Collection) using the liquid fermentation medium of Example 3; Take the soil from the field vegetable plot (without baking and sterilization) for indoor simulation tests, with each pot weighing about 5 kg. First, add beta-cypermethrin artificially to the soil to make the beta-cypermethrin content reach 500 mg / kg; after standing for 48 h, take 50 mL of the prepared inoculants with different treatments, dilute them 100 times with water respectively, and spray them evenly onto the soil in the form of spraying, stirring evenly while spraying; use spraying the same amount of sterile water as the control, and set 3 replicates for each treatment. Detect the original deposition amount of beta-cypermethrin in the soil 2 h after the inoculant is applied, keep the indoor temperature at 20 - 34 °C, turn the soil gently regularly and spray to supplement water to keep the soil humidity at 40% - 60%. After 30 d, take the soil of each treatment according to the "five-point sampling method", analyze and detect the residual amount of beta-cypermethrin in the soil by the method of Example 5, and calculate the degradation rate (%).

[0061] Degradation rate = (1 - wT / w0) × 100%, where wT is the residual amount after 30 d of treatment, and w0 is the original deposition amount.

[0062] Table 6 Degradation rates of beta-cypermethrin under different treatments in indoor soil culture conditions

[0063] The results are shown in Table 6. After 30 d of inoculating the tomato brown rugose fruit virus-induced antibacterial agent sample 1, the residual amount of beta-cypermethrin in the soil of treatment 1 decreased from 500 mg / L to 124.381 mg / L, and the degradation rate reached 75.28%. While the degradation rates of beta-cypermethrin in the soils of treatment 2 (inoculating control strain 1) and treatment 3 (inoculating control strain 2) were 25.97% and 32.14% respectively, indicating that Serratia marcescens WF01 has a strong degradation effect on beta-cypermethrin.

[0064] Experimental Example 3: Degradation effect of different treatments on beta-cypermethrin under field test conditions This example provides a degradation test of different treatments on beta-cypermethrin under field test conditions. The test method and the settings of each treatment are as follows: Control group: sterile water; Treatment 1: Tomato brown rugose fruit virus-induced antibacterial agent sample 1 prepared in Example 3 (0.5×10 9 cfu / mL); Treatment 2: Liquid inoculant (0.5×10 9 cfu / mL) prepared from the control strain 1 (Serratia marcescens CGMCC 1.4256, purchased from China General Microbiological Culture Collection Center) using the liquid fermentation medium of Example 3; Treatment 3: The liquid bacterium agent (0.5×10 9 cfu / mL) prepared with the liquid fermentation medium of Example 3 was used for the control strain 2 (Serratia marcescens CICC 10370, purchased from China Center for Industrial Culture Collection).

[0065] The experiment was carried out in a pepper planting greenhouse in Shouguang City, Shandong Province. The pepper variety was thread pepper. Lambda-cyhalothrin was sprayed during the vigorous growth period of pepper to kill aphids. The recommended spraying amount was 30 mL / mu (the liquid medicine concentration was 450 mg / L). The experiment was divided into 5 plots, each plot was 20m 2 . After 2 h of spraying, pepper leaves and rhizosphere soil were collected in different plots to determine the initial deposition amount of lambda-cyhalothrin. For each treatment, 50-fold liquid bacterium agent (dosage 5 L / mu) was used for root irrigation 1 d after spraying. The control group was irrigated with sterile water. After 7 d of root irrigation with the bacterium agent, pepper leaves and rhizosphere soil were taken respectively to determine the residual amount of lambda-cyhalothrin. The pepper leaves were reduced by the quartering method, and 1 / 4 of the leaves were taken and put into a crusher to be broken into samples, which were then put into a self-sealing bag and stored in a -20°C refrigerator. Rhizosphere soil samples: They were reduced by the quartering method, weeds and stones were removed, and then they were sieved. Samples were made, put into a self-sealing bag, and stored in a -20°C refrigerator.

[0066] The determination method of lambda-cyhalothrin in leaves referred to GB / T 5009.110-2003 Determination of Residues of Cypermethrin, Fenvalerate and Deltamethrin in Vegetable Foods. The method of Example 2 was used to determine the content of lambda-cyhalothrin in soil. Degradation rate = (1−wT / w0)×100%, where wT is the residual amount after 7 d of treatment and w0 is the initial deposition amount.

[0067] Table 7 Degradation of Lambda-cyhalothrin by Different Treatments under Field Test Conditions

[0068] The experimental results showed that: after 7 d of spraying, the degradation rates of lambda-cyhalothrin in pepper leaves and soil in the control group were 22.09% and 14.58% respectively. The degradation rates of lambda-cyhalothrin in pepper leaves and soil after root irrigation with the tomato brown rugose fruit virus-induced antibacterial agent sample 1 (Treatment 1) prepared in Example 3 were 76.80% and 78.95% respectively. The degradation rates of lambda-cyhalothrin in pepper leaves and soil after root irrigation with the control bacterium agent 1 (Treatment 2) and the control bacterium agent 2 (Treatment 3) were 22.40% and 6.58%, 14.76% and 11.86% respectively, indicating that root irrigation of pepper with the Serratia marcescens WF01 of the present invention can achieve a large-scale degradation of the residual lambda-cyhalothrin in pepper planting soil and pepper plants.

[0069] Test Example 4: This example provides the field control efficacy of different treatments against Tomato brown rugose fruit virus. The test method and each treatment are set as follows: Control group: blank control; Treatment 1: Sample 1 of the antibacterial agent against Tomato brown rugose fruit virus prepared in Example 3 (0.5×10 9 cfu / mL); Treatment 2: Sample 2 of the antibacterial agent against Tomato brown rugose fruit virus prepared in Example 4 (0.8×10 9 cfu / mL); Treatment 3: Sample 3 of the antibacterial agent against Tomato brown rugose fruit virus prepared in Example 5 (1.0×10 9 cfu / mL); Treatment 4: Liquid bacterium agent (0.5×10 9 cfu / mL) prepared from the control strain 1 (Serratia marcescens CGMCC 1.4256, purchased from China General Microbiological Culture Collection Center) using the liquid fermentation medium in Example 3; Treatment 5: Liquid bacterium agent (0.5×10 9 cfu / mL) prepared from the control strain 2 (Serratia marcescens CICC 10370, purchased from China National Center for Industrial Culture Collection) using the liquid fermentation medium in Example 3.

[0070] The test was carried out in Weifang City, Shandong Province. The test crop was pepper, and the variety was thread pepper. The test greenhouse was a pepper planting greenhouse where Tomato brown rugose fruit virus disease occurred and had not been disinfected. The plot area was 72m 2 , arranged in a randomized block design with 4 replicates. The fertility of the test field was uniform, the planting and management levels were the same, and the disease incidence and damage degree were severe. The pepper seeds were raised in seedlings, and when they grew to 2 true leaves, they were transplanted into the test greenhouse. The 50-fold liquid of each treatment bacterium agent (dosage 5L / acre) was irrigated at the transplanting stage and the early flowering stage respectively. Protection rows were set between each treatment and around the test area. When obvious symptoms appeared in the control group, the incidence rate was investigated. 50 plants were continuously investigated along the ridges in each plot, and the grading records were made in units of plants. The disease index was statistically calculated, and the control efficacy was calculated. The symptom grading standard of Tomato brown rugose fruit virus disease was used to investigate the disease occurrence of diseased plants, and the disease index and relative control effect of each treatment were calculated.

[0071] Symptom grading standard of Tomato brown rugose fruit virus disease: Grade 0: No symptoms; Grade 1: The veins of the young leaves are clear veins, and 1 - 2 true leaves show mosaic; Grade 3: The middle and upper leaves show mosaic; Grade 5: Most leaves show mosaic, and a few leaves are deformed; Grade 7: Most leaves show severe mosaic, deformation, and shrinkage; Grade 9: Almost all leaves show severe mosaic, deformation, and shrinkage, and the plant is significantly dwarfed. The calculation formulas for the disease index and relative control efficacy are as follows: Disease index = ∑(number of diseased plants at each level × value of that disease level) / (total number of plants surveyed × highest disease level value) × 100 Relative control efficacy = (disease index of control - disease index of treatment) / disease index of control × 100%.

[0072] Table 8 Field control efficacy of different treatments against tomato brown rugose fruit virus

[0073] As can be seen from Table 8, Treatment 1 (Sample 1 of tomato brown rugose fruit virus-induced antibacterial agent), Treatment 2 (Sample 2 of tomato brown rugose fruit virus-induced antibacterial agent), and Treatment 3 (Sample 3 of tomato brown rugose fruit virus-induced antibacterial agent) have good control efficacy against tomato brown rugose fruit virus occurring on field pepper crops, and the relative control efficacy can reach 71.26% - 76.92%, which is significantly better than Treatment 4 (control strain 1) and Treatment 5 (control strain 2); it shows that the Serratia marcescens WF01 of the present invention can effectively prevent and control tomato brown rugose fruit virus disease by root irrigation during the growth period of pepper.

[0074] Only some exemplary embodiments of the present invention have been described by way of illustration above. Undoubtedly, for those of ordinary skill in the art, various different ways can be used to modify the described embodiments without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. Serratia marcescens WF01 for degrading pesticides, characterized by: The Serratia marcescens WF01 was deposited in the General Microbiological Center of the China Microbiological Culture Collection Administration on April 17, 2024, with a deposit number of CGMCCNO.30368 and a deposit address of Beichen West Road, Chaoyang District, Beijing. It was classified and named Serratia marcescens Serratia marcescens .

2. Tomato brown wrinkled fruit virus induced antimicrobial agent, characterized in that: The tomato brown fruit virus-inducing antibacterial agent comprises the Serratia marcescens WF01 for degrading pesticides as claimed in claim 1.

3. The tomato brown wrinkled fruit virus antimicrobial agent as claimed in claim 2, characterized in that: The tomato brown wrinkled fruit virus induced antibacterial agent has the function of degrading pyrethroid insecticides.

4. The tomato brown wrinkle fruit virus inducing antibacterial agent as claimed in claim 3, characterized in that: The active ingredient of the pyrethroid insecticide is high-efficiency cypermethrin or high-efficiency cyhalothrin or cypermethrin.

5. The tomato brown wrinkled fruit virus inducing antibacterial agent as claimed in claim 4, characterized in that: The highly effective cypermethrin is the highly effective cypermethrin remaining in pepper planting soil and / or pepper body.

6. The tomato brown wrinkled fruit virus inducing antibacterial agent as claimed in claim 2, characterized in that: The tomato brown wrinkled fruit virus induced antibacterial agent is used during the growth period of peppers in a root irrigation treatment manner.

7. A method for preparing the tomato brown wrinkle fruit virus antimicrobial agent as claimed in claim 2, characterized in that: The Serratia marcescens WF01 is streaked onto a solid culture medium with highly effective cypermethrin as the sole carbon source, and inverted for 36 to 40 hours at 32° C.; a bright red single colony is picked and inoculated into a liquid culture medium with highly effective cypermethrin as the sole carbon source, and shake-cultured at 32° C. and 185 r / min for 48 hours to obtain a seed solution of the Serratia marcescens WF01; the seed solution is inoculated into a liquid culture medium without any carbon source at a volume ratio of 10%, and shake-cultured at 28° C. and 185 r / min for 3 to 5 hours, and then yeast extract is added, and shake-cultured at 28° C. and 200 r / min for 48 hours to obtain the tomato brown wrinkled fruit virus induced antibacterial agent, which is a dark red fermentation liquid of Serratia marcescens WF01.

8. The method according to claim 7, characterized in that: The content of prodigiosin in the tomato brown wrinkled fruit virus induced antibacterial agent is 13.5-17.2 g / L, and the effective viable bacteria count is 0.5×10 9 cfu / mL~1.0×10 9 cfu / mL.

9. The method according to claim 8, characterized in that: The tomato brown wrinkled fruit virus-inducing antibacterial agent can improve the ability of the Serratia marcescens WF01 in preventing and controlling tomato brown wrinkled fruit virus disease.

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