Niabella pedocola R34 and its applications

Abstract

This invention relates to the field of microbial technology and provides strains. Niabella pedocola R34 and its applications. Strain R34 has a significant degradation effect on nicosulfuron, and can degrade high concentrations of nicosulfuron with a fast degradation rate and high degradation rate. It has a good degradation effect on nicosulfuron in soil and water.

Description

Technical Field

[0001] This invention relates to the field of microbial technology, and more specifically, to strains. Niabella pedocola R34 and its applications. Background Technology

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

[0003] Nicosulfuron, also known as zearalenone, has the chemical name [2-(4,6-dimethoxypyrimidin-2-pyrimidinylaminocarbamoylsulfonyl)-N,N-dimethylnicotinamide], and its structural formula is as follows: Figure 8 As shown.

[0004] Nicosulfuron primarily kills weeds by inhibiting the activity of acetolactate synthase, thus preventing weed cells from synthesizing certain essential amino acids and hindering normal mitosis. Its high selectivity and good safety profile make it popular among farmers.

[0005] While nicosulfuron can effectively control weeds and increase the yield of crops such as corn, recent studies have revealed that although it does not directly harm farmland soil, long-term use leads to its accumulation in the soil. This can result in reduced yields of subsequent crops, thus jeopardizing my country's food security. Furthermore, nicosulfuron is water-soluble, meaning it may seep into groundwater and surface water with rainfall, polluting water sources and potentially harming aquatic animals and human health.

[0006] Under natural conditions, nicosulfuron mainly degrades through three pathways. Photodegradation generally only occurs in the surface layer of soil, which is quite limited. Chemical hydrolysis mainly occurs under acidic and neutral conditions, and it cannot function under alkaline conditions. In contrast, 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 purpose of this invention is to provide strains Niabella pedocola R34 and its applications.

[0008] To achieve the objectives of this invention, in a first aspect, this invention provides strain R34, isolated and screened from black soil samples from Siping, Jilin Province, and classified as... Niabella pedocola The strain is now deposited at the China General Microbiological Culture Collection Center, No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, 100101, China, accession number CGMCC No. 31997, deposit date September 19, 2024.

[0009] Secondly, the present invention provides a microbial preparation comprising one or more of the following: bacterial cells, bacterial powder, bacterial suspension, fermentation products, fermentation broth, fermentation broth extract, etc., selected from the strain R34.

[0010] Thirdly, the present invention provides a method for preparing the microbial preparation, the method comprising 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, strain R34 was cultured using R2A medium.

[0013] Preferably, 1L of R2A medium contains 0.4-0.6g of yeast extract, 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, with the remainder being water (such as distilled water), and a pH of 7.0-7.5.

[0014] More preferably, 1L of R2A medium contains 0.5g yeast extract, 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, and 0.3g sodium pyruvate, with the balance being water, and pH 7.2.

[0015] Fourthly, the present invention provides the application of the strain R34 or the microbial preparation in any of the following:

[0016] (1) Used in the preparation of degradable sulfonylurea herbicides;

[0017] (2) Used to degrade sulfonylurea herbicides.

[0018] Preferably, it is used to degrade sulfonylurea herbicides in soil and water.

[0019] Preferably, the sulfonylurea herbicide of the present invention is selected from one or more of nicosulfuron, methasulfuron, monosulfuron, bensulfuron, thifensulfuron, bensulfuron, methasulfuron, chlorsulfuron or mesosulfuron, and more preferably nicosulfuron.

[0020] Fifthly, the present invention provides a method for degrading sulfonylurea herbicides, using the strain R34 or the microbial preparation to degrade sulfonylurea herbicides.

[0021] Furthermore, it is used to degrade sulfonylurea herbicides added to MSG culture medium.

[0022] MSG basal medium without added sulfonylurea herbicides contains, per 1L: 0.4-0.6g potassium dihydrogen phosphate, 0.9-1.1g disodium hydrogen phosphate dodecahydrate, 0.18-0.22g magnesium sulfate heptahydrate, 1.0-1.3g ammonium chloride, 0.9-1.1g glucose, 1.8-2.2mL trace elements, and 1.8-2.2mL vitamins, with the remainder being water (such as distilled water), pH 7.2-7.5.

[0023] Each 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, with the remainder being water (such as distilled water).

[0024] Preferably, the MSG basal medium without added sulfonylurea herbicides contains, per 1L, 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, with the remainder being water, and pH 7.3.

[0025] One liter 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, with the remainder being water.

[0026] 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.

[0027] 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.

[0028] Furthermore, the concentration of the sulfonylurea herbicide is below 500 mg / L; preferably below 350 mg / L; more preferably below 250 mg / L.

[0029] By employing the above technical solution, the present invention has at least the following advantages and beneficial effects:

[0030] The strain provided by this invention Niabella pedocola R34 has a significant degradation effect on nicosulfuron, and can degrade high concentrations of nicosulfuron. It has a fast degradation rate and a high degradation rate, and has a good degradation effect on nicosulfuron in soil and water. Attached Figure Description

[0031] Figure 1 For the present invention Niabella Colony morphology of strain R34.

[0032] Figure 2 For the present invention Niabella Electron micrograph of bacterial cell morphology of strain R34.

[0033] Figure 3 For the present invention Niabella Phylogenetic tree of strain R34 and similar type strains.

[0034] Figure 4 The degradation curve of R34 nicosulfuron provided in Example 3 of the present invention.

[0035] Figure 5 The effect of temperature on the degradation of nicosulfuron by R34 is shown in Example 4 of this invention.

[0036] Figure 6 The effect of pH on the degradation of nicosulfuron by R34 is provided in Example 4 of this invention.

[0037] Figure 7 The effect of substrate concentration on the degradation of nicosulfuron by R34, as provided in Example 4 of this invention.

[0038] Figure 8 This is the structural formula of nicosulfuron in this invention.

[0039] Figure 9 In Embodiment 5 of the present invention Niabella Remediation experiment of strain R34 on nicosulfuron-contaminated sites. Detailed Implementation

[0040] This invention provides a method for degrading nicosulfuron. Niabella sp. Strain R34 of the genus *Bacillus* and its applications: This bacterium has a significant degradation effect on nicosulfuron, and by exploring the changes in its degradation rate under different conditions, it provides a material basis for future applications in the degradation of nicosulfuron in soil and water.

[0041] The present invention adopts the following technical solution:

[0042] This invention provides a nicosulfuron-degrading bacterium. Niabella pedocola R34 and its application in soil and water remediation. The strain was isolated and screened from black soil samples in the Lishu-Maize-Soybean Black Soil Demonstration Area of ​​Siping City, Jilin Province. Strain R34 exhibits significant degradation activity against nicosulfuron, providing a material basis for the remediation of nicosulfuron pollution in soil.

[0043] strain Niabella pedocolaR34 is deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 31997.

[0044] The Niabella The 16S rRNA gene sequence of strain R34 is shown in SEQ ID NO:1.

[0045] The Niabella After being cultured on R2A solid medium for 1 day, strain R34 exhibited the following phenotypic characteristics: orange, round colonies with smooth surfaces. The optimal growth temperature was 20-40℃, and the pH ranged from 6-8. Under transmission electron microscopy, the cells appeared elliptical, with a size of (0.3-0.5) µm × (1.8-2.7) µm.

[0046] The type strain most similar in sequence to the nicosulfuron-degrading strain is Niabella pedocola R384T The full-length similarity of the 16S rRNA sequence was 99.93%. Similar sequences were selected. Niabella A phylogenetic tree was constructed from the 16S rRNA gene sequence of the bacterial model strain. See the phylogenetic tree below. Figure 3 Sequence similarity and evolutionary relationships prove that it is... Niabella A member of the genus *Bacteria*.

[0047] 1L of 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 remainder is distilled water; pH 7.3. 1L of trace elements contains: 5g dipotassium hydrogen phosphate, 2.5g magnesium sulfate, 2.5g sodium chloride, 0.05g ferrous sulfate, 0.05g manganese sulfate, and the remainder is distilled water.

[0048] 1L of R2A solid medium contains: 0.5g yeast extract, 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, with the remainder being distilled water; pH 7.2.

[0049] The present invention also provides a microbial preparation comprising the above-mentioned... Niabella One or more of the following: bacterial cells, bacterial powder, bacterial suspension, fermentation products, fermentation broth, and fermentation broth extract of strain R34.

[0050] This invention also provides a method for preparing the aforementioned microbial preparation, the method comprising culturing the preparation. Niabella Steps for strain R34.

[0051] The method for preparing the microbial agent includes culturing the...Niabella The strain R34 was subjected to experiments at 28-32°C and pH 7.0-7.5, preferably at 29-31°C and pH 7.2-7.4, and even more preferably at 30°C and pH 7.3.

[0052] Preferably, the culture is carried out using R2A medium. Niabella strain R34.

[0053] Preferably, 1L of R2A medium contains 0.4-0.6g of yeast extract, 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, with the remainder preferably being water, more preferably distilled water, and a pH of 7.0-7.5.

[0054] More preferably, 1L of R2A medium contains 0.5g yeast extract, 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, and 0.3g sodium pyruvate, with a pH of 7.2.

[0055] The present invention also provides the following Niabella The use of strain R34 or the aforementioned microbial preparation in any one or more of the following:

[0056] (1) Preparation of degradable sulfonylurea herbicides;

[0057] (2) Degradation of sulfonylurea herbicides.

[0058] Preferably, it degrades sulfonylurea herbicides in soil and water.

[0059] Preferably, the sulfonylurea herbicide is one or more of nicosulfuron, methasulfuron, succinylsulfuron, bensulfuron, thifensulfuron, bensulfuron, methasulfuron, chlorsulfuron, or mesosulfuron.

[0060] More preferably, the sulfonylurea herbicide is nicosulfuron.

[0061] The present invention also provides a method for degrading sulfonylurea herbicides, utilizing the aforementioned Niabella Strain R34 or the aforementioned microbial preparations degrade sulfonylurea herbicides.

[0062] Preferably, the sulfonylurea herbicide is one or more of nicosulfuron, methasulfuron, succinylsulfuron, bensulfuron, thifensulfuron, bensulfuron, methasulfuron, chlorsulfuron, or mesosulfuron.

[0063] More preferably, the sulfonylurea herbicide is nicosulfuron.

[0064] The method for degrading sulfonylurea herbicides utilizes MSG medium. 1L of MSG medium contains: 0.4-0.6g potassium dihydrogen phosphate, 0.9-1.1g disodium hydrogen phosphate dodecahydrate, 0.18-0.22g magnesium sulfate heptahydrate, 1.0-1.3g ammonium chloride, 0.9-1.1g glucose, 1.8-2.2mL trace elements, and 1.8-2.2mL vitamins, preferably with the remainder being water, more preferably distilled water, with a pH of 7.2-7.5.

[0065] 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, with the remainder preferably being water, and more preferably distilled water.

[0066] Preferably, the 1L MSG culture medium 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;

[0067] 1L of trace elements contains: 5g dipotassium hydrogen phosphate, 2.5g magnesium sulfate, 2.5g sodium chloride, 0.05g ferrous sulfate, and 0.05g manganese sulfate.

[0068] According to the method for degrading sulfonylurea herbicides, the temperature of the environment in which the Niabella strain R34 or the microbial preparation is used is 20-40°C; preferably 25-35°C; more preferably 30°C; and / or

[0069] The Niabella The pH value of the environment in which strain R34 or the microbial preparation is used is 4.5-7.5; preferably 4-7; more preferably 6.9-7.1, and even more preferably 7.

[0070] According to the method for degrading sulfonylurea herbicides, the concentration of the sulfonylurea herbicide is less than 500 mg / L; preferably less than 350 mg / L; and more preferably less than 250 mg / L.

[0071] The nicosulfuron-degrading bacterium R34 provided by this invention can achieve a degradation rate of over 85% in 10 days in MSG medium with a nicosulfuron concentration of 100 mg / L. This can greatly reduce the enrichment of nicosulfuron in soil or water, and it has a fast growth rate and low cost, which can be put into large-scale and rapid use, thus contributing to environmental protection.

[0072] The following examples are used to illustrate the present invention, but are not intended to limit the scope of the 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.

[0073] Example 1: Isolation and screening of nicosulfuron-degrading bacteria R34

[0074] Five g of black soil samples were collected from the corn and soybean growing area of ​​Lishu County, Siping City. These samples were added to 100 mL of nicosulfuron enrichment medium at a concentration of 30 mg / L and cultured at 30℃ and 150 rpm. Every two weeks, the samples were transferred at a 10% (v / v) transfer rate to fresh basal inorganic salt medium (BSM) supplemented with nicosulfuron for continuous enrichment. The nicosulfuron concentrations were successively 50 mg / L, 80 mg / L, and 100 mg / L. After serial dilution, appropriate gradients were selected and plated onto solid media such as R2A, BSM, and MSG supplemented with nicosulfuron. Single colonies with uniform morphology on the plates were selected for further purification and culture.

[0075] 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 remainder 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 remainder is distilled water.

[0076] The above 1L R2A solid culture medium contains: 0.5g yeast extract, 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 being water; pH 7.2.

[0077] The above 1L basal inorganic salt solid culture 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 remainder is distilled water; pH 7.3. 1L trace element medium contains: 5g dipotassium hydrogen phosphate, 2.5g magnesium sulfate, 2.5g sodium chloride, 0.05g ferrous sulfate, 0.05g manganese sulfate, 15g agar, and the remainder is distilled water.

[0078] The above 1L microbial enrichment solid culture 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 remainder 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 remainder is distilled water.

[0079] The isolated and purified single colonies were inoculated into 5 mL of R2A medium and cultured for 48 hours. After centrifugation at 6000 r / min for 3 minutes, the supernatant was discarded, and the colonies were resuspended in 2 mL of sterile PBS. After centrifugation at 6000 r / min for 3 minutes, the colonies were washed twice in this manner. The colonies were then resuspended in 2 mL of MSG medium, and 1 mL of the resuspended colonies were added to MSG medium with a nicosulfuron concentration of 100 mg / L. The colonies were cultured at 30 °C and 150 rpm for 7 days with shaking. The degradation effect was determined by high performance liquid chromatography, and it was found that strain R34 had the function of degrading nicosulfuron.

[0080] The specific conditions for liquid chromatography were as follows: Agilent 1200 high-performance liquid chromatography; SPC18 reversed-phase column (5μm × 4.6mm × 150mm); mobile phase: acetonitrile: 0.2% acetic acid gradient, program shown in Table 1; flow rate: 1mL / min; detection wavelength: 254nm.

[0081] Table 1

[0082]

[0083] Example 2 Identification of nicosulfuron-degrading bacterium R34

[0084] Phenotypic characteristics: When strain R34 was inoculated onto R2A plates and grown at 30°C for 1 day, the colonies were orange, round, and smooth. Figure 1 The growth temperature is 20-40℃, and the pH is 6-8. Under transmission electron microscopy, the cells are oval-shaped, with a size of (0.3-0.5) µm × (1.8-2.7) µm. Figure 2 ).

[0085] Phylogenetic identification based on 16S rRNA sequence: Strain R34 was inoculated into R2A medium and cultured in a shaker at 30℃ for 1 day. 2 μl of bacterial culture was used as a template for PCR amplification using universal bacterial primers 27F and 1492R. 2×Es Taq Master Mix premixed solution from Kangwei Century Biotechnology Co., Ltd. was used. The PCR reaction volume was 30 μl, specifically: 2 μl bacterial culture, 1 μl 27F primer, 1 μl 1492R primer, 15 μl 2×Es Taq Master Mix, and ddH2O was added to bring the volume to 30 μl. The reaction program was: 94℃ for 5 min, 94℃ for 30 s, 55℃ for 30 s, 72℃ for 60 s, 30 cycles, 72℃ for 5 min. The purified PCR product was sent to Tianyi Huiyuan Biotechnology Co., Ltd. for sequencing. The obtained DNA sequence was uploaded to the EZBioCloud database for sequence alignment, obtaining the known sequence with the highest similarity to the aligned sequence and the standard strain sequence. Analysis revealed that the sequence with the highest similarity to the compared sequence was... Niabella bacteria( Niabella pedocola The similarity was 99.93%. This indicates that the degrading bacteria isolated in this invention belong to... Niabella Fungi.

[0086] Example 3 The present invention Niabella Degradation efficiency of bacteria on nicosulfuron in liquid culture medium

[0087] The isolated and purified strain R34 was inoculated into 5 mL of R2A medium and cultured for 48 hours. After centrifugation at 6000 rpm for 3 minutes, the supernatant was discarded, and the culture was resuspended in 2 mL of sterile PBS. This was followed by centrifugation at 6000 rpm for 3 minutes, and the culture was repeated twice. The culture was then resuspended in 2 mL of MSG medium, and 1 mL of the suspension was added to MSG medium containing 100 mg / L nicosulfuron. The culture was incubated at 30°C and 150 rpm for 10 days. The degradation rate was then detected using high-performance liquid chromatography (HPLC), and it reached 85%. The specific degradation curve is shown below. Figure 4 As shown.

[0088] Example 4: Study on the optimal conditions for strain R34 to degrade nicosulfuron

[0089] To investigate the effect of strain R34 on the degradation rate of nicosulfuron under different conditions, and to find the optimal conditions for strain R34 to degrade nicosulfuron, the following method was used: MSG medium with a nicosulfuron concentration of 100 mg / L was prepared. 1L of medium contained the following: 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, pH 7.3, with the remainder being distilled water. The trace elements (1L) consisted of: 5 g dipotassium hydrogen phosphate, 2.5 g magnesium sulfate, 2.5 g sodium chloride, 0.05 g ferrous sulfate, 0.050 g manganese sulfate, with the remainder being distilled water. Strain R34 was inoculated into the medium at a 5% inoculum and cultured at 20℃, 25℃, 30℃, 35℃, and 40℃ on a shaker at 150 rpm for 10 days. The degradation rate was determined by high-performance liquid chromatography (HPLC). The results are as follows: Figure 5 As shown, the degradation efficiency of R34 increases with increasing temperature, reaching a maximum of 89.25% at 30℃, and then gradually decreases. At 40℃, this bacterium has no degradation effect on nicosulfuron.

[0090] In MSG medium with a nicosulfuron concentration of 100 mg / L, the medium formulation was as follows: 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 remainder being distilled water. The trace elements (1 L) consisted of: 5 g dipotassium hydrogen phosphate, 2.5 g magnesium sulfate, 2.5 g sodium chloride, 0.05 g ferrous sulfate, 0.050 g manganese sulfate, and the remainder being distilled water. Strain R34 was inoculated into the medium at a 5% inoculum, and the pH was adjusted to 5.0, 6.0, 7.0, 8.0, and 9.0, respectively. The medium was cultured at 30℃ and 150 rpm on a shaker. After 10 days, the degradation rate was determined by high-performance liquid chromatography (HPLC). The results are as follows: Figure 6 As shown, strain R34 exhibits higher degradation rates of nicosulfuron at pH 6.0 and 7.0, reaching a maximum degradation rate of 91.25% at pH 6.0; while the degradation rate of nicosulfuron is lower at pH < 6.0 and pH > 7.0.

[0091] Under conditions of 30℃ and pH 7, strain R34 was inoculated into MSG medium at a 5% inoculum concentration. 1L of MSG medium contained: 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 remainder being distilled water. The trace elements (1L) consisted of: 5g dipotassium hydrogen phosphate, 2.5g magnesium sulfate, 2.5g sodium chloride, 0.05g ferrous sulfate, 0.050g manganese sulfate, and the remainder being distilled water. Nicosulfuron concentrations of 50mg / L, 100mg / L, 150mg / L, 200mg / L, and 300mg / L were prepared in the medium. The culture was incubated on a shaker at 150rpm for 10 days. The degradation rate was determined by high-performance liquid chromatography (HPLC). The results are as follows: Figure 7 As shown, the degradation rate of R34 decreased with increasing initial substrate concentration, with the highest degradation rate of 99.75% at 50 mg / L.

[0092] Example 5: Remediation Experiment of Strain R34 on Nicosulfuron-Contaminated Sites

[0093] Four 2×2 m experimental plots were prepared for this experiment. 400 ml of nicosulfuron herbicide was purchased and dissolved in 20 L of water, then sprayed on both the experimental and control groups. OD... 600 The R34 bacterial solution with a concentration of 0.6 was applied to the experimental group in the same volume as the herbicide, while the control group was sprayed with the same volume of water.

[0094] Between 0 and 5 days after nicosulfuron spraying, 5 kg of soil samples were collected daily from both the experimental and control groups using a five-point method. The collected soil samples were immediately cryogenically preserved and promptly sent back to the Beijing laboratory for nicosulfuron determination. Results are as follows... Figure 9 As shown.

[0095] 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, demonstrating its potential in practical applications.

[0096] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. The strain Niabella pedocola R34, with accession number CGMCC No.31997.

2. A microbial preparation, characterized in that, It contains one or more of the following: bacterial cells, bacterial powder, and bacterial suspension selected from strain R34 of claim 1.

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

4. The preparation method according to claim 3, characterized in that, The strain R34 was cultured at 28-32℃ and pH 7.0-7.

5.

5. The preparation method according to claim 4, characterized in that, The strain R34 was cultured at 29-31℃ and pH 7.2-7.

4.

6. The preparation method according to claim 5, characterized in that, The strain R34 was cultured at 30°C and pH 7.

3.

7. The preparation method according to any one of claims 3-6, characterized in that, The strain R34 was cultured using R2A medium; One liter of R2A culture medium contains 0.4-0.6 g of yeast extract. 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, with the balance being water, pH 7.0-7.

5.

8. The preparation method according to claim 7, characterized in that, 1L of R2A medium contains 0.5g of yeast extract. 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, and 0.3g sodium pyruvate, with the balance being water, pH 7.

2.

9. The strain R34 of claim 1 or the microbial preparation of claim 2 may be used in any of the following applications: (1) Used in the preparation of degradable sulfonylurea herbicides; (2) Used to degrade sulfonylurea herbicides; The sulfonylurea herbicide mentioned is nicosulfuron.

10. A method for degrading sulfonylurea herbicides, characterized in that, The strain R34 of claim 1 or the microbial preparation of claim 2 is used to degrade sulfonylurea herbicides; The sulfonylurea herbicide mentioned is nicosulfuron.

11. The method according to claim 10, characterized in that, The ambient temperature for using strain R34 or the microbial preparation is 20-40℃; and / or, The pH value of the environment in which the strain R34 or the microbial preparation is used is 4.5-7.

5.

12. The method according to claim 11, characterized in that, The ambient temperature for using strain R34 or the microbial preparation is 25-35℃; and / or, The pH value of the environment in which the strain R34 or the microbial preparation is used is 4-7.

13. The method according to claim 12, characterized in that, The ambient temperature for using strain R34 or the microbial preparation is 30°C; and / or, The pH value of the environment in which the strain R34 or the microbial preparation is used is 6.9-7.

1.

14. The method according to claim 13, characterized in that, The pH value of the environment in which the strain R34 or the microbial preparation is used is 7.

15. The method according to any one of claims 10-14, characterized in that, The concentration of the sulfonylurea herbicide is below 500 mg / L.

16. The method according to claim 15, characterized in that, The concentration of the sulfonylurea herbicide is below 350 mg / L.

17. The method according to claim 16, characterized in that, The concentration of the sulfonylurea herbicide is below 250 mg / L.

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