Strain Niabella pedocola R34 and application thereof

Abstract

The invention relates to the technical field of microorganisms, and provides a strain Niabella pedocola R34 and application thereof. The strain R34 has an obvious degradation effect on the nicosulfuron, can degrade high-concentration nicosulfuron, is high in degradation rate and degradation rate, and has a better degradation effect on the nicosulfuron in soil and water.

Description

Technical Field

[0001] The present invention relates to the field of microbial technology, and in particular to strains Niabella pedocola R34 and its applications. Background Art

[0002] In agricultural production, the increase in crop yields is closely related to the contribution of pesticides, with herbicides accounting for about 47% of the total pesticide use. Nicosulfuron, as one of the sulfonylurea herbicides, plays a key role in corn cultivation.

[0003] Nicosulfuron is also known as corn music, and its chemical name is [2-(4, 6-dimethoxypyrimidine-2-pyrimidinylcarbamidesulfonyl)-N, N-dimethylnicotinamide], and its structural formula is as follows Figure 8 shown.

[0004] Nicosulfuron mainly inhibits the activity of acetolactate synthase, thereby preventing weed cells from synthesizing some essential amino acids and failing to complete mitosis normally, thereby achieving the purpose of killing weeds. It is widely favored by farmers for its high selectivity and good safety.

[0005] Although Nicosulfuron can effectively remove weeds and increase the yield of crops such as corn, in recent years, people have found that although Nicosulfuron has no direct toxic effect on farmland soil, due to long-term use, Nicosulfuron will accumulate in the soil, which will lead to a reduction in the yield of subsequent crops and endanger my country's food security. In addition, Nicosulfuron is soluble in water, so it may flow into groundwater and surface water with rainfall, pollute water sources and endanger the health of aquatic animals and people.

[0006] Under natural conditions, nicosulfuron has three main degradation modes. Photodegradation generally only occurs in the surface layer of the soil, which has great limitations, while chemical hydrolysis mainly occurs under acidic and neutral conditions and cannot work under alkaline conditions. Microbial degradation has a fast rate, multiple degradation pathways, and high degradation efficiency, and has gradually become the main direction of pesticide degradation research in recent years. Summary of the invention

[0007] The present invention aims to provide a strain Niabella pedocola R34 and its applications.

[0008] In order to achieve the purpose of the present invention, in the first aspect, the present invention provides a strain R34 isolated and screened from a black soil sample in Siping, Jilin Province, which is classified and named Niabella pedocola The strain has been deposited in the General Microbiology Center of China Microbiological Culture Collection Administration, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, Postal Code 100101, with the deposit number CGMCC No. 31997 and the deposit date September 19, 2024.

[0009] In a second aspect, the present invention provides a microbial preparation comprising one or more selected from the bacterial bodies, bacterial powders, bacterial suspensions, fermentation products, fermentation broths, fermentation broth extracts, etc. of the strain R34.

[0010] In a third aspect, the present invention provides a method for preparing the microbial preparation, which comprises the step of culturing the strain R34.

[0011] Furthermore, the strain R34 is cultured at 28-32°C and pH 7.0-7.5, preferably at 29-31°C and pH 7.2-7.4, and more preferably at 30°C and pH 7.3.

[0012] Furthermore, the strain R34 was cultured using R2A medium.

[0013] Preferably, 1L R2A medium contains 0.4-0.6g yeast powder, 0.4-0.6g peptone, 0.4-0.6g acid hydrolyzed casein, 0.4-0.6g glucose, 0.4-0.6g soluble starch, 0.2-0.4g dipotassium hydrogen phosphate, 0.04-0.06g magnesium sulfate heptahydrate and 0.28-0.32g sodium pyruvate, and the balance is water (such as distilled water), pH 7.0-7.5; More preferably, 1 L of R2A medium contains 0.5 g of yeast powder, 0.5 g of peptone, 0.5 g of acid-hydrolyzed casein, 0.5 g of glucose, 0.5 g of soluble starch, 0.3 g of dipotassium hydrogen phosphate, 0.05 g of magnesium sulfate heptahydrate and 0.3 g of sodium pyruvate, with the balance being water, and the pH value is 7.2.

[0014] In a fourth aspect, the present invention provides the strain R34 or the microbial preparation for any of the following applications: (1) Used to prepare products that degrade sulfonylurea herbicides; (2) Used to degrade sulfonylurea herbicides.

[0015] Preferably, it is used to degrade sulfonylurea herbicides in soil and water.

[0016] Preferably, the sulfonylurea herbicide of the present invention is selected from one or more of nicosulfuron-methyl, sulfosulfuron-methyl, monosulfuron-methyl, benzylsulfuron-methyl, thifensulfuron-methyl, bensulfuron-methyl, metsulfuron-methyl, chlorosulfuron-methyl or mesosulfuron-methyl, more preferably nicosulfuron-methyl.

[0017] In a fifth aspect, the present invention provides a method for degrading sulfonylurea herbicides, using the strain R34 or the microbial preparation to degrade sulfonylurea herbicides.

[0018] Furthermore, it is used to degrade the sulfonylurea herbicides added to the MSG culture medium.

[0019] The MSG basic culture medium without the addition of sulfonylurea herbicides contains, per liter, 0.4-0.6 g of potassium dihydrogen phosphate, 0.9-1.1 g of disodium hydrogen phosphate dodecahydrate, 0.18-0.22 g of magnesium sulfate heptahydrate, 1.0-1.3 g of ammonium chloride, 0.9-1.1 g of glucose, 1.8-2.2 mL of trace elements and 1.8-2.2 mL of vitamins, with the balance being water (such as distilled water), with a pH of 7.2-7.5.

[0020] Among them, 1L of trace elements contains 4.5-5.5g of dipotassium hydrogen phosphate, 2.3-2.7g of magnesium sulfate, 2.3-2.7g of sodium chloride, 0.04-0.06g of ferrous sulfate and 0.04-0.06g of manganese sulfate, and the remainder is water (such as distilled water).

[0021] Preferably, the MSG basal medium without adding sulfonylurea herbicides contains 0.5 g of potassium dihydrogen phosphate, 1 g of disodium hydrogen phosphate dodecahydrate, 0.2 g of magnesium sulfate heptahydrate, 1.1 g of ammonium chloride, 1 g of glucose, 2 mL of trace elements and 2 mL of vitamins, and the balance is water, pH 7.3. Among them, 1L of trace elements contains 5g of dipotassium hydrogen phosphate, 2.5g of magnesium sulfate, 2.5g of sodium chloride, 0.05g of ferrous sulfate and 0.05g of manganese sulfate, and the rest is water.

[0022] Furthermore, the temperature of the environment in which the strain R34 or the microbial preparation is used is 20-40°C; preferably 25-35°C; more preferably 30°C.

[0023] Furthermore, the pH value of the environment in which the strain R34 or the microbial preparation is used is 4.5-7.5; preferably 4-7; further preferably 6.9-7.1, and more preferably 7.

[0024] Furthermore, the concentration of the sulfonylurea herbicide is 500 mg / L or less; preferably 350 mg / L or less; more preferably 250 mg / L or less.

[0025] By means of the above technical solution, the present invention has at least the following advantages and beneficial effects: The strain provided by the present invention Niabella pedocola R34 has a significant degradation effect on Nicosulfuron and can degrade high-concentration Nicosulfuron with a fast degradation rate and high degradation rate. It has a good degradation effect on Nicosulfuron in soil and water. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 For the present invention Niabella Colony morphology of strain R34.

[0027] Figure 2 For the present invention Niabella Electron microscopic image of bacterial morphology of strain R34.

[0028] Figure 3 For the present invention Niabella Phylogenetic tree of strain R34 and similar model strains.

[0029] Figure 4 This is the degradation curve of R34 Nicosulfuron provided in Example 3 of the present invention.

[0030] Figure 5 The effect of temperature on the degradation of nicosulfuron by R34 provided in Example 4 of the present invention.

[0031] Figure 6 The effect of pH on the degradation of nicosulfuron by R34 provided in Example 4 of the present invention.

[0032] Figure 7 The effect of substrate concentration on the degradation of nicosulfuron by R34 provided in Example 4 of the present invention.

[0033] Figure 8 It is the structural formula of Nicosulfuron of the present invention.

[0034] Figure 9 In Example 5 of the present invention Niabella Remediation experiment of nicosulfuron-contaminated sites using strain R34. DETAILED DESCRIPTION

[0035] The present invention provides a method for degrading nicosulfuron Niabella sp. The strain R34 of the genus and its application, which has a significant degradation effect on Nicosulfuron, and by exploring the changes in its degradation rate under different conditions, provides a material basis for the degradation of Nicosulfuron in soil and water in the future.

[0036] The present invention adopts the following technical solution: The invention provides a nicosulfuron-degrading bacterium Niabella pedocola R34 and its application in soil and water restoration. The strain was isolated and screened from black soil samples in the Lishu corn and soybean black soil demonstration area in Siping, Jilin. The strain R34 has a significant degradation effect on Nicosulfuron, providing a material basis for repairing Nicosulfuron pollution in soil.

[0037] strain Niabella pedocola R34 is deposited in the General Microbiology Center of China Microorganism Culture Collection Administration with the deposit number CGMCC No. 31997.

[0038] Said NiabellaThe 16S rRNA gene sequence of strain R34 is shown in SEQ ID NO:1.

[0039] Said Niabella After one day of culture on R2A solid medium, strain R34 had the following phenotypic characteristics: orange, round, smooth colonies. The growth temperature was 20-40℃, pH 6-8. Under transmission electron microscopy, the cells were oval, with a cell size of (0.3-0.5)µm×(1.8-2.7)µm.

[0040] The model strain most similar to the nicosulfuron-degrading strain sequence is Niabella pedocola R384T , the full-length similarity of 16S rRNA sequence is 99.93%. Niabella The phylogenetic tree was constructed based on the 16S rRNA gene sequence of the model strain of the bacterium. Figure 3 . Sequence similarity and evolutionary relationship prove that it is Niabella A member of the genus Bacteria.

[0041] 1L enriched medium (MSG) contains: 0.5g potassium dihydrogen phosphate, 1g disodium hydrogen phosphate dodecahydrate, 0.2g magnesium sulfate heptahydrate, 1.1g ammonium chloride, 1g glucose, 200mg nicosulfuron, 2mL trace elements, 2mL vitamins, and the balance is distilled water; pH 7.3. 1L trace elements contain: 5g dipotassium hydrogen phosphate, 2.5g magnesium sulfate, 2.5g sodium chloride, 0.05g ferrous sulfate, 0.05 0g manganese sulfate, and the balance is distilled water.

[0042] 1L R2A solid culture medium contains: 0.5g yeast powder, 0.5g peptone, 0.5g acid hydrolyzed casein, 0.5g glucose, 0.5g soluble starch, 0.3g dipotassium hydrogen phosphate, 0.05g magnesium sulfate heptahydrate, 0.3g sodium pyruvate, 15g agar, and the balance is distilled water; pH 7.2.

[0043] The present invention also provides a microbial preparation comprising the Niabella One or more of the bacterial cells, bacterial powder, bacterial suspension, fermentation product, fermentation broth, and fermentation broth extract of strain R34.

[0044] The present invention also provides a method for preparing the microbial preparation, which comprises culturing the Niabella Steps for strain R34.

[0045] The preparation method of the microbial preparation comprises culturing the Niabella The strain R34 is cultured at 28-32°C and pH 7.0-7.5, preferably at 29-31°C and pH 7.2-7.4, and more preferably at 30°C and pH 7.3.

[0046] Preferably, the R2A medium is used to culture the Niabella strain R34.

[0047] Preferably, 1L R2A medium contains 0.4-0.6g of yeast powder, 0.4-0.6g of peptone, 0.4-0.6g of acid hydrolyzed casein, 0.4-0.6g of glucose, 0.4-0.6g of soluble starch, 0.2-0.4g of dipotassium hydrogen phosphate, 0.04-0.06g of magnesium sulfate heptahydrate and 0.28-0.32g of sodium pyruvate, and the balance is preferably water, more preferably distilled water, pH 7.0-7.5.

[0048] Further preferably, 1 L of R2A medium contains 0.5 g of yeast powder, 0.5 g of peptone, 0.5 g of acid-hydrolyzed casein, 0.5 g of glucose, 0.5 g of soluble starch, 0.3 g of dipotassium hydrogen phosphate, 0.05 g of magnesium sulfate heptahydrate and 0.3 g of sodium pyruvate, with a pH of 7.2.

[0049] The present invention also provides the Niabella Use of strain R34 or the microbial preparation in any one or more of the following: (1) Preparation of products for degrading sulfonylurea herbicides; (2) Degradation of sulfonylurea herbicides.

[0050] Preferably, sulfonylurea herbicides are degraded in soil and water.

[0051] Preferably, the sulfonylurea herbicide is one or more of nicosulfuron-methyl, sulfosulfuron-methyl, monosulfuron-methyl, benzylsulfuron-methyl, thifensulfuron-methyl, bensulfuron-methyl, metsulfuron-methyl, chlorosulfuron-methyl or mesosulfuron-methyl.

[0052] More preferably, the sulfonylurea herbicide is nicosulfuron.

[0053] The present invention also provides a method for degrading sulfonylurea herbicides, using the Niabella The strain R34 or the microbial preparation degrades sulfonylurea herbicides.

[0054] Preferably, the sulfonylurea herbicide is one or more of nicosulfuron-methyl, sulfosulfuron-methyl, monosulfuron-methyl, benzylsulfuron-methyl, thifensulfuron-methyl, bensulfuron-methyl, metsulfuron-methyl, chlorosulfuron-methyl or mesosulfuron-methyl.

[0055] More preferably, the sulfonylurea herbicide is nicosulfuron.

[0056] The method for degrading sulfonylurea herbicides uses MSG culture medium, wherein 1L of MSG culture medium contains: 0.4-0.6g of potassium dihydrogen phosphate, 0.9-1.1g of disodium hydrogen phosphate dodecahydrate, 0.18-0.22g of magnesium sulfate heptahydrate, 1.0-1.3g of ammonium chloride, 0.9-1.1g of glucose, 1.8-2.2mL of trace elements and 1.8-2.2mL of vitamins, preferably the balance is water, more preferably distilled water, and the pH is 7.2-7.5; 1L of trace elements contains: 4.5-5.5g of dipotassium hydrogen phosphate, 2.3-2.7g of magnesium sulfate, 2.3-2.7g of sodium chloride, 0.04-0.06g of ferrous sulfate and 0.04-0.06g of manganese sulfate, and the balance is preferably water, more preferably distilled water.

[0057] Preferably, the 1L MSG medium formula contains: 0.5g potassium dihydrogen phosphate, 1g disodium hydrogen phosphate dodecahydrate, 0.2g magnesium sulfate heptahydrate, 1.1g ammonium chloride, 1g glucose, 2mL trace elements and 2mL vitamins, pH 7.3; 1L of trace elements contains: 5g of dipotassium hydrogen phosphate, 2.5g of magnesium sulfate, 2.5g of sodium chloride, 0.05g of ferrous sulfate and 0.05g of manganese sulfate.

[0058] According to the method for degrading sulfonylurea herbicides, the temperature of the use environment of the Niabella strain R34 or the microbial preparation is 20-40°C; preferably 25-35°C; more preferably 30°C; and / or, Said Niabella The pH value of the use environment of the strain R34 or the microbial preparation is 4.5-7.5; preferably 4-7; further preferably 6.9-7.1, and more preferably 7.

[0059] According to the method for degrading sulfonylurea herbicides, the concentration of the sulfonylurea herbicides is 500 mg / L or less, preferably 350 mg / L or less, and more preferably 250 mg / L or less.

[0060] The nicosulfuron-degrading bacteria R34 provided by the present invention can achieve a degradation rate of more than 85% in an MSG culture medium with a nicosulfuron concentration of 100 mg / L in 10 days, can greatly reduce the degree of enrichment of nicosulfuron in soil or water, has a fast growth rate, low use cost, can be put into use on a large scale and quickly, and is beneficial to protecting environmental safety.

[0061] The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art, and the raw materials used are all commercially available products.

[0062] Example 1 Isolation and Screening of Nicosulfuron-Degrading Bacteria R34 5g of black soil sample from corn and soybean planting area in Lishu County, Siping was collected, and 100mL of nicosulfuron enrichment medium with nicosulfuron concentration of 30mg / L was added, and enrichment culture was carried out at 30℃ and 150rpm. Every two weeks, the transfer volume was transferred to fresh basal inorganic salt medium (BSM) with nicosulfuron added at 10% (volume fraction) for continuous enrichment. The nicosulfuron concentration was 50mg / L, 80mg / L, and 100mg / L, respectively. After gradient dilution, the appropriate gradient was selected and coated on solid culture media such as R2A, BSM and MSG with nicosulfuron added, and single colonies with single morphology on the plate were selected for further purification and culture.

[0063] The above 1L microbial enrichment medium (MSG) contains: 0.5g potassium dihydrogen phosphate, 1g disodium hydrogen phosphate dodecahydrate, 0.2g magnesium sulfate heptahydrate, 1.1g ammonium chloride, 1g glucose, 200mg nicosulfuron, 2mL trace elements, 2mL vitamins, and the balance is distilled water; pH 7.3. Trace elements (1L): 5g dipotassium hydrogen phosphate, 2.5g magnesium sulfate, 2.5g sodium chloride, 0.05g ferrous sulfate, 0.050g manganese sulfate, and the balance is distilled water.

[0064] The above 1L R2A solid culture medium contains: 0.5g yeast powder, 0.5g peptone, 0.5g acid hydrolyzed casein, 0.5g glucose, 0.5g soluble starch, 0.3g dipotassium hydrogen phosphate, 0.05g magnesium sulfate heptahydrate, 0.3g sodium pyruvate, 15g agar, and the balance is water; pH 7.2.

[0065] The above 1L basic inorganic salt solid medium (BSM) contains: 0.5g potassium dihydrogen phosphate, 1g disodium hydrogen phosphate dodecahydrate, 0.2g magnesium sulfate heptahydrate, 1.1g ammonium chloride, 2mL trace elements, 2mL vitamins, 15g agar, and the balance is distilled water; pH 7.3. 1L trace elements contain: 5g dipotassium hydrogen phosphate, 2.5g magnesium sulfate, 2.5g sodium chloride, 0.05g ferrous sulfate, 0.05 0g manganese sulfate, 15g agar, and the balance is distilled water.

[0066] The above 1L microbial enrichment solid medium (MSG) contains: 0.5g potassium dihydrogen phosphate, 1g disodium hydrogen phosphate dodecahydrate, 0.2g magnesium sulfate heptahydrate, 1.1g ammonium chloride, 1g glucose, 200mg nicosulfuron, 2mL trace elements, 2mL vitamins, 15g agar, and the balance is distilled water; pH 7.3. Trace elements (1L): 5g dipotassium hydrogen phosphate, 2.5g magnesium sulfate, 2.5g sodium chloride, 0.05g ferrous sulfate, 0.050g manganese sulfate, and the balance is distilled water.

[0067] The single colony isolated and purified above was inoculated into 5 mL of R2A medium and cultured for 48 hours, then centrifuged at 6000 r / min for 3 minutes, the supernatant was discarded, the culture was resuspended with 2 mL of sterile PBS, and the culture was centrifuged at 6000 r / min for 3 minutes. After washing twice in this way, the culture was resuspended with 2 mL of MSG medium, and 1 mL was added to MSG medium with a nicosulfuron concentration of 100 mg / L. After shaking culture at 30°C and 150 rpm for 7 days, the degradation effect was determined by high performance liquid chromatography, and it was found that strain R34 has the function of degrading nicosulfuron.

[0068] The specific conditions of liquid chromatography are: Agilent 1200 high performance liquid chromatography; SPC18 reverse phase column (5μm ×4.6mm ×150mm); mobile phase: acetonitrile: 0.2% acetic acid gradient change, the program is shown in Table 1; flow rate: 1mL / min. Detection wavelength: 254nm.

[0069] Table 1

[0070] Example 2 Identification of Nicosulfuron-degrading Bacteria R34 Phenotypic characteristics: strain R34 was inoculated on R2A plate and grown at 30°C for 1 day. The colonies were orange, round, and smooth ( Figure 1 ). The growth temperature is 20-40℃, pH 6-8. Under transmission electron microscopy, the cells are oval in shape and the cell size is (0.3-0.5)µm×(1.8-2.7)µm ( Figure 2 ).

[0071] Phylogenetic identification based on 16S rRNA sequences: strain R34 was inoculated into R2A medium and cultured at 30°C for 1 day. 2 μl of bacterial solution was taken as template and PCR amplified with bacterial universal primers 27F and 1492R. The 2×Es Taq Master Mix premix from Kangwei Century Biotech Co., Ltd. was used. The PCR reaction system was 30 μl, specifically: 2 μl of bacterial solution, 1 μl of 27F primer, 1 μl of 1492R primer, 15 μl of 2×Es Taq Master Mix, and ddH 2 O was added to 30 μl. The reaction program was: 94℃5min, 94℃30s, 55℃30s, 72℃60s, 30 cycles, 72℃5min. The purified PCR product was sent to Tianyi Huiyuan Biotechnology Co., Ltd. for sequencing, and the obtained DNA sequence was uploaded to the EZBioCloud database for sequence comparison to obtain the known sequence and standard strain sequence with the highest similarity to the comparison sequence. After analysis, it was found that the sequence with the highest similarity to the comparison sequence was Niabella bacteria( Niabella pedocola), with a similarity of 99.93%. This indicates that the degradation bacteria isolated by the present invention belong to Niabella Bacteria.

[0072] Example 3 The present invention Niabella Degradation efficiency of nicosulfuron in liquid culture medium The isolated and purified strain R34 was inoculated into 5mL R2A medium and cultured for 48 hours, then centrifuged at 6000r / min for 3 minutes, the supernatant was discarded, and the suspension was resuspended with 2mL sterile PBS, and centrifuged at 6000r / min for 3 minutes. After washing twice in this way, the suspension was resuspended with 2mL MSG medium, and 1mL of the bacterial suspension was added to MSG medium with a nicosulfuron concentration of 100mg / L. After shaking culture at 30℃ and 150rpm for 10 days, the degradation rate was detected by high performance liquid chromatography, and the degradation rate can reach 85%. The specific degradation curve is shown in the figure below. Figure 4 shown.

[0073] Example 4 Study on the Optimal Conditions for Degrading Nicosulfuron by Strain R34 In order to explore the effect of strain R34 on the degradation rate of Nicosulfuron under different conditions, so as to find the optimal conditions for strain R34 to degrade Nicosulfuron. The specific method is: in MSG medium with a Nicosulfuron concentration of 100 mg / L, the formula of 1L culture medium is: 0.5g potassium dihydrogen phosphate, 1g disodium hydrogen phosphate dodecahydrate, 0.2g magnesium sulfate heptahydrate, 1.1g ammonium chloride, 1g glucose, 200mg Nicosulfuron, 2mL trace elements, 2mL vitamins, pH7.3, and the rest is distilled water. Trace elements (1L): 5g potassium dihydrogen phosphate, 2.5g magnesium sulfate, 2.5g sodium chloride, 0.05g ferrous sulfate, 0.050g manganese sulfate, and the rest is distilled water. Strain R34 was inoculated in the culture medium at a 5% inoculation rate, and the temperatures were 20℃, 25℃, 30℃, 35℃, and 40℃, respectively, and the shaking culture was 150rpm. After 10 days, its degradation rate was determined by high performance liquid chromatography. The results are as follows Figure 5 As shown in the figure, the degradation efficiency of R34 increased with the increase of temperature and reached a maximum of 89.25% at 30℃, and then began to decrease gradually. At 40℃, the bacteria had no degradation effect on nicosulfuron.

[0074] In the MSG medium with a nicosulfuron concentration of 100 mg / L, the medium formula is: 0.5 g potassium dihydrogen phosphate, 1 g disodium hydrogen phosphate dodecahydrate, 0.2 g magnesium sulfate heptahydrate, 1.1 g ammonium chloride, 1 g glucose, 200 mg nicosulfuron, 2 mL trace elements, 2 mL vitamins, and the balance is distilled water. Trace elements (1L): 5 g potassium dihydrogen phosphate, 2.5 g magnesium sulfate, 2.5 sodium chloride, 0.05 g ferrous sulfate, 0.050 g manganese sulfate, and the balance is distilled water. The strain R34 was inoculated into the culture medium at a 5% inoculation rate, and the pH was adjusted to 5.0, 6.0, 7.0, 8.0, and 9.0, respectively. It was cultured in a shaking incubator at 30°C and 150 rpm. After 10 days, its degradation rate was determined by high performance liquid chromatography. The results are as follows Figure 6 As shown, the degradation rate of nicosulfuron by strain R34 was higher at pH 6.0 and 7.0, and reached the highest degradation rate of 91.25% at pH 6.0; the degradation rate of nicosulfuron by the strain was lower at pH < 6.0 and pH > 7.0.

[0075] At 30°C and pH 7, strain R34 was inoculated in MSG medium at a 5% inoculation rate. The formula of 1L MSG medium contains: 0.5g potassium dihydrogen phosphate, 1g disodium hydrogen phosphate dodecahydrate, 0.2g magnesium sulfate heptahydrate, 1.1g ammonium chloride, 1g glucose, 200mg nicosulfuron, 2mL trace elements, 2mL vitamins, and the balance is distilled water. Trace elements (1L): 5g potassium dihydrogen phosphate, 2.5g magnesium sulfate, 2.5 sodium chloride, 0.05g ferrous sulfate, 0.050g manganese sulfate, and the balance is distilled water. The concentration of nicosulfuron in the culture medium was prepared to 50mg / L, 100mg / L, 150mg / L, 200mg / L, and 300mg / L, respectively, and cultured on a shaking table at 150rpm. After 10 days, the degradation rate was determined by high performance liquid chromatography. The results are as follows Figure 7 As shown, the degradation rate of R34 decreased with the increase of initial substrate concentration, and the highest degradation rate was 99.75% at 50 mg / L.

[0076] Example 5 Remediation experiment of nicosulfuron-contaminated sites with strain R34 Four groups of 2×2 m experimental plots were prepared for the experiment. 400 ml of nicosulfuron herbicide was purchased and dissolved in 20 L of water and sprayed on the experimental group and the control group. 600 = 0.6 of R34 bacterial solution was sprinkled into the experimental group with the same volume of herbicide, and the control group was sprayed with the same volume of water.

[0077] Between 0 and 5 days after spraying Nicosulfuron, 5 kg of soil samples were collected from the experimental group and the control group every day according to the five-point method. The collected soil samples were immediately stored at low temperature and sent back to the Beijing laboratory in time for Nicosulfuron determination. Figure 9 shown.

[0078] On the fifth day after spraying the bacterial solution, the degradation rate of Nicosulfuron in the soil was significantly higher than that of the control group, indicating that strain R34 can effectively promote the degradation of Nicosulfuron in the actual soil environment in the field, showing its potential in practical applications.

[0079] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. Strains Niabella pedocola R34, the deposit number is CGMCC No. 31997.

2. A microbial preparation, characterized in that: It comprises one or more selected from the bacterial bodies, bacterial powders, bacterial suspensions, fermentation products, fermentation broth, and fermentation broth extracts of the strain R34 according to claim 1.

3. The method for preparing the microbial preparation according to claim 2, characterized in that: The preparation method comprises the step of culturing the strain R34.

4. The preparation method according to claim 3, characterized in that: The strain R34 is cultured at 28-32°C and pH 7.0-7.5, preferably at 29-31°C and pH 7.2-7.4, and more preferably at 30°C and pH 7.

3.

5. The preparation method according to claim 3 or 4, characterized in that: Cultivating the strain R34 using R2A medium; Preferably, 1L R2A medium contains 0.4-0.6g yeast powder, 0.4-0.6g peptone, 0.4-0.6g acid hydrolyzed casein, 0.4-0.6g glucose, 0.4-0.6g soluble starch, 0.2-0.4g dipotassium hydrogen phosphate, 0.04-0.06g magnesium sulfate heptahydrate and 0.28-0.32g sodium pyruvate, and the balance is water, pH 7.0-7.5; More preferably, 1 L of R2A medium contains 0.5 g of yeast powder, 0.5 g of peptone, 0.5 g of acid-hydrolyzed casein, 0.5 g of glucose, 0.5 g of soluble starch, 0.3 g of dipotassium hydrogen phosphate, 0.05 g of magnesium sulfate heptahydrate and 0.3 g of sodium pyruvate, with the balance being water, and the pH value is 7.

2.

6. The strain R34 according to claim 1 or the microbial preparation according to claim 2 is used in any of the following applications: (1) Used to prepare products that degrade sulfonylurea herbicides; (2) Used to degrade sulfonylurea herbicides; Preferably, it is used to degrade sulfonylurea herbicides in soil and water; Preferably, the sulfonylurea herbicide is selected from one or more of nicosulfuron-methyl, sulfosulfuron-methyl, monosulfuron-methyl, benzylsulfuron-methyl, thifensulfuron-methyl, bensulfuron-methyl, metsulfuron-methyl, chlorosulfuron-methyl or mesosulfuron-methyl; More preferably, the sulfonylurea herbicide is nicosulfuron.

7. A method for degrading sulfonylurea herbicides, characterized in that: Degrading sulfonylurea herbicides using the strain R34 of claim 1 or the microbial preparation of claim 2; Preferably, the sulfonylurea herbicide is selected from one or more of nicosulfuron-methyl, sulfosulfuron-methyl, monosulfuron-methyl, benzylsulfuron-methyl, thifensulfuron-methyl, bensulfuron-methyl, metsulfuron-methyl, chlorosulfuron-methyl or mesosulfuron-methyl; More preferably, the sulfonylurea herbicide is nicosulfuron.

8. The method according to claim 7, characterized in that Used to degrade sulfonylurea herbicides added to MSG culture medium; The MSG basal medium without adding sulfonylurea herbicides contains 0.4-0.6g of potassium dihydrogen phosphate, 0.9-1.1g of disodium hydrogen phosphate dodecahydrate, 0.18-0.22g of magnesium sulfate heptahydrate, 1.0-1.3g of ammonium chloride, 0.9-1.1g of glucose, 1.8-2.2mL of trace elements and 1.8-2.2mL of vitamins, and the balance is water, pH 7.2-7.5; Among them, 1L of trace elements contains 4.5-5.5g of dipotassium hydrogen phosphate, 2.3-2.7g of magnesium sulfate, 2.3-2.7g of sodium chloride, 0.04-0.06g of ferrous sulfate and 0.04-0.06g of manganese sulfate, and the balance is water; Preferably, the MSG basal medium without adding sulfonylurea herbicides contains 0.5 g of potassium dihydrogen phosphate, 1 g of disodium hydrogen phosphate dodecahydrate, 0.2 g of magnesium sulfate heptahydrate, 1.1 g of ammonium chloride, 1 g of glucose, 2 mL of trace elements and 2 mL of vitamins, and the balance is water, pH 7.

3. Among them, 1L of trace elements contains 5g of dipotassium hydrogen phosphate, 2.5g of magnesium sulfate, 2.5g of sodium chloride, 0.05g of ferrous sulfate and 0.05g of manganese sulfate, and the rest is water.

9. The method according to claim 7, characterized in that: The temperature of the environment in which the strain R34 or the microbial preparation is used is 20-40°C; preferably 25-35°C; more preferably 30°C; and / or, The pH value of the environment in which the strain R34 or the microbial preparation is used is 4.5-7.5; preferably 4-7; further preferably 6.9-7.1, and more preferably 7.

10. The method according to any one of claims 7 to 9, characterized in that: The concentration of the sulfonylurea herbicide is 500 mg / L or less, preferably 350 mg / L or less, and more preferably 250 mg / L or less.

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