Triazine herbicide prometryn-degrading bacterium and application thereof

Abstract

The application discloses a triazine herbicide propoxur degrading bacterial strain and application thereof, the bacterial strain is SWFU-DH02 strain which is negative in gram staining reaction and is identified as Microbacterium sp. Exiguobacteruim sp. ) on November 22, 2021, and is deposited in the China General Microbiological Culture Collection Center, and the strain preservation number is CGMCC No. 23948. The application discloses, for the first time, the degradation effect of Microbacterium sp. Exiguobacteruim sp. ) on triazine herbicide propoxur, and a Microbacterium sp. high-efficiency degrading bacterium SWFU-DH02 is screened, the degradation efficiency of the bacterium on propoxur can reach 75.08%, and the bacterium grows optimally under the conditions of pH 7.0, temperature 28 DEG C and salt concentration 1%. The degrading bacterial strain SWFU-DH02 has the characteristics of simple culture, rapid growth and high efficiency of degradation. The application can solve the pollution problem of triazine herbicide propoxur in soil or water, prevent the phytotoxicity of herbicide residues on subsequent crops, and produce non-toxic and non-polluting green agricultural products. The application provides a new biological approach for modern pesticide pollution control.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of microbial degradation, and particularly relates to a Microbacterium sp. and application thereof in degrading triazine herbicide prometryn. BACKGROUND

[0002] Triazine herbicides have a long persistence period in soil and a long half-life, are easy to remain in soil, are not easy to be degraded, and are easy to be washed into rivers and lakes by rainwater to pollute water bodies. Prometryn is a low-toxicity s-triazine herbicide, and is one of the most representative herbicides of this type. It is widely used in the removal of gramineous and broad-leaved green weeds in the fields of crops such as wheat, vegetables, rice, cotton and corn due to its high herbicidal effect. Prometryn is a non-ionic, weakly polar hydrophobic compound, and has an average solubility in water. It is stable in slightly acidic, slightly alkaline and neutral environments. The biological degradation half-life of prometryn in aerobic and anaerobic soil is 1-3 months, and it can stably exist in the field for 12-18 months after long-term application of prometryn. Its production and use as a herbicide are released into the environment, causing direct harm to humans through the food chain. Therefore, prometryn has been listed as a reproductive and developmental toxicant by the United States Environmental Protection Agency, and as an endocrine disruptor on the European Union priority list. However, due to its broad-spectrum and high efficiency in controlling weeds, prometryn is still widely used in rice, sugarcane and soybean producing areas in China. Therefore, degrading prometryn is an important aspect of ecological restoration.

[0003] Studies have shown that photodegradation, herbicide adjuvants, physical adsorbents and molecularly imprinted polymers can remove prometryn. Photodegradation can reduce the content of prometryn in soil, but this process takes a long time. The use of herbicide adjuvants may affect the biodegradation of recalcitrant compounds. Physical adsorbents can remove prometryn in water, and molecularly imprinted polymers have been used to analyze trace amounts of herbicides in culture media; however, these methods cannot solve the problem of prometryn residues in soil.

[0004] Microbial degradation is one of the key processes for the attenuation of herbicides in the environment. This process has gradually become a research hotspot due to its low cost, high efficiency and no secondary pollution. Although it has been banned in several countries, prometryn is still a widely used herbicide in China. Biodegradation may be an ideal method for degrading prometryn residues in soil. At present, there are few reports on the biodegradation pathway of prometryn. Therefore, screening of environmentally friendly strains that can effectively degrade prometryn residues and developing microecological preparations that can be applied to environmental remediation not only enriches the prometryn-degrading flora, but also provides a theoretical basis for the application of bioremediation in natural environments. SUMMARY

[0005] In order to solve the above problems existing in the prior art for degrading residual prometryn, the first object of the present application is to provide a microbacterium (Microbacterium sp.) Exiguobacteruim sp. ) for degrading the triazine herbicide prometryn.

[0006] The second object of the present application is to provide a microbacterium strain SWFU-DH02 capable of efficiently degrading the triazine herbicide prometryn.

[0007] Another object of the present application is to provide the application of the microbacterium strain SWFU-DH02 in degrading the triazine herbicide prometryn.

[0008] The above objects of the present application are achieved by the following technical solutions:

[0009] The present application is a prometryn-degrading bacterial strain isolated from a sugarcane farmland in Yingjiang County, Dehong Prefecture, Yunnan Province, which has been applying prometryn for a long time, and is named Microbacterium SWFU-DH02. It was preserved in the China General Microbiological Culture Collection Center on November 22, 2021, with the preservation number CGMCC NO. 23948 and the preservation address being No. 3, Beichen West Road, Chaoyang District, Beijing.

[0010] The strain can grow by utilizing prometryn as the sole carbon source, and can degrade 50 mg / L of prometryn in the inorganic salt medium within 24 hours. The degradation efficiency is determined by a gas chromatograph-mass spectrometer (GC-MS), and the degradation efficiency reaches 75.08%, with obvious degradation effect. By changing the temperature, pH and salt concentration of the single variable, and measuring the OD 600 value of the bacterial growth, it is determined that the optimal growth temperature of the microbacterium SWFU-DH02 is 28℃, the optimal pH is 7.0, and the optimal NaCl concentration is 1%.

[0011] The experimental results show that the microbacterium SWFU-DH02 has good degradation effect on prometryn, with a degradation rate of 75.08%, and can be effectively applied to the degradation of residual prometryn.

[0012] Therefore, the following applications should be within the protection scope of the present application:

[0013] Application of the microbacterium in degrading the triazine herbicide prometryn or preparing a degrading bacterial agent.

[0014] Application of the microbacterium SWFU-DH02 in degrading the triazine herbicide prometryn or preparing a degrading bacterial agent.

[0015] A bacterial agent containing the microbacterium for efficiently degrading the triazine herbicide prometryn should also be within the protection scope of the present application.

[0016] The present application has the following beneficial effects:

[0017] This invention discloses for the first time a microbacterium ( Exiguobacteruim sp. The degradation effect on the triazine herbicide prednisolone.

[0018] Meanwhile, this invention screened a highly efficient and rapid microbacterium SWFU-DH02 that degrades promethazine, enriching the germplasm resource bank of pesticide-degrading bacteria. It has significant application value in remediating water bodies and soils with triazine herbicide residues, providing a new approach for controlling triazine herbicide residues. Attached Figure Description

[0019] Figure 1 The colony morphology of the degrading bacterium SWFU-DH02.

[0020] Figure 2 Electrophoresis diagram of 16S rDNA amplification products of strain SWFU-DH02.

[0021] Figure 3 A phylogenetic tree of the degrading bacterium SWFU-DH02 was constructed based on the 16S rDNA sequence.

[0022] Figure 4 This is a scanning electron microscope image of SWFU-DH02.

[0023] Figure 5 This is the standard curve for chlorpyrifos.

[0024] Figure 6 The degradation curve of the bacterium SWFU-DH02 that degrades chlorpyrifos.

[0025] Figure 7 The growth curve of SWFU-DH02, a bacterium that degrades chlorpyrifos.

[0026] Figure 8 The effect of pH concentration on the growth of the degrading bacterium SWFU-DH02.

[0027] Figure 9 The effect of NaCl concentration on the growth of the degrading bacterium SWFU-DH02.

[0028] Figure 10 The effect of temperature on the growth of the degrading bacterium SWFU-DH02. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in this technical field.

[0030] The culture medium formulation used in this invention is as follows:

[0031] Basic salt medium (MSM): K2HPO4 1 g, KH2PO4 1 g, (NH4)2SO4 0.5 g, MgSO4·7H2O 0.3 g, NaCl 1 g, deionized water 1.0 L. PH is adjusted to 7.2, high-temperature and high-pressure sterilization 121℃, 20 min

[0032] LB solid medium: agar powder 13 g, sodium chloride 10 g, deionized water 1.0 L, yeast powder 5 g, tryptone 10 g. pH is adjusted to 7.0. High-temperature and high-pressure sterilization 121℃, 20 min

[0033] LB liquid medium: sodium chloride 10 g, deionized water 1.0 L, yeast powder 5 g, tryptone 10 g. PH is adjusted to 7.0, high-temperature and high-pressure sterilization 121℃, 20 min.

[0034] Example 1 Isolation, purification and identification of degrading bacteria

[0035] 1. Enrichment culture of diafenthiuron degrading bacteria

[0036] Take 5 g of active soil sample and add it to a conical flask containing 100 mL of sterilized basic salt medium with diafenthiuron 30 mg / L, and carry out enrichment culture in a constant temperature shaking incubator at 28℃ and 160 r / min in the dark. Take 5% of the culture liquid and inoculate it into the same newly prepared sterilized basic salt medium, and continuously increase the concentration of diafenthiuron until the concentration of diafenthiuron in the medium is 150 mg / L. The operation is carried out in a clean bench.

[0037] 2. Screening of diafenthiuron degrading bacteria

[0038] After 5 weeks of culture by the above method, gradient dilution and purification culture method is used, 1 mL of culture liquid is taken for gradient purification and dilution, and is diluted by 10 -1 , 10 -2 , 10 -3 , 10 -4 , 10 -5 , 10 -6 , 10 -7 times, respectively. Then 0.1 ml of bacterial liquid is taken from each gradient and spread on the medium added with diafenthiuron (150 mg / L), and the medium is placed in a constant temperature incubator at 28℃ and cultured for 2-3 days. The growth of bacteria is observed during the process, and the size, number and distribution of bacterial colonies at different dilution multiples have certain regularity. Single colonies with good growth and no contamination are selected, and plate streaking method is used for strain purification, and placed in a 28℃ incubator for culture for 2-3 days, and repeated for 3-4 times. (The operation method and matters needing attention during the experiment are adjusted according to the contamination, and strain contamination is reduced), and finally the purified diafenthiuron degrading strain is obtained, numbered as SWFU-DH02.

[0039] 3. Identification of strain SWFU-DH02

[0040] (1) Morphological identification

[0041] Strain SWFU-DH02 was inoculated on LB solid plate and cultured at 28°C for 3 days, and the colony morphology was observed. The purified strain was inoculated on LB solid medium by plate streaking method and cultured at 28°C for 2-3 days, and the colony morphology was observed, as shown in the following. Figure 1 Colony morphology of the degrading bacteria: the colony was light yellow round cake, smooth surface, regular edge, and slightly raised in the middle

[0042] (2) Physiological and biochemical identification

[0043] The physiological and biochemical characteristics of strain SWFU-DH02 were identified, and the results showed that the strain was a gram-negative bacterium, the gelatin liquefaction test was negative, and the nitrate reduction experiment was negative. The physiological and biochemical test results are shown in Table 1.

[0044] Table 1 Physiological and biochemical identification of degrading bacteria Y-1

[0045] Detection index Detection result Gram staining － Glucose fermentation detection － Lactose sugar fermentation detection － Sucrose sugar fermentation detection － Gelatin liquefaction detection － Nitrate reduction detection － Glucose gas production detection －

[0046] Note: "+" represents a positive reaction result; "-" represents a negative reaction result

[0047] (3) 16S rDNA molecular biology identification

[0048] Total DNA of degrading bacteria SWFU-DH02 was extracted according to the method in the Ezup column bacterial genome DNA extraction kit instruction, and then PCR amplification was performed using 16S rDNA bacterial universal primers (27F: 5'-AGAGTTTGATCCTGGCTCAG-3'; 1429R: 5'-GGTTACCTTGTTACGACTT-3') provided by Shuoqin Biotechnology Co., Ltd. The PCR amplification product was mixed with 10X loading buffer and then subjected to electrophoresis detection by 1% agarose gel, and the results are shown in the following. Figure 2 It can be seen that the amplification effect is good, and the PCR amplification product is sent to Shengong Biotechnology Co., Ltd. for sequencing. The sequencing results are submitted to GenBank database and registered, and the registration number is: OL588221. At the same time, the 16S rDNA sequence of the strain is compared and analyzed by BLAST in GenBank database, and the related sequences with higher homology are selected to construct a phylogenetic tree and analyze the evolutionary relationship by MAGE 7.0 software (the 16S rDNA phylogenetic tree is shown in the following). Figure 3

[0049] ​The strain SWFU-DH02 obtained by separation and purification is closest to the evolution distance of Parvibacter Exiguobacteruim sp. , the scanning electron microscope observation characteristics are as shown in Figure 4 , the culture characteristics are most similar to Parvibacter Exiguobacteruim sp. , and therefore, according to the identification results, the degradation strain SWFU-DH02 obtained by screening is identified as Parvibacter Exiguobacteruim sp. , which was preserved in the China General Microbiological Culture Collection Center on November 22, 2021, with a preservation number of CGMCC NO. 23948 and a preservation address of No. 3, Beichen West Road, Chaoyang District, Beijing.

[0050] Example 2: Growth and degradation curve determination of the strain SWFU-DH02 in the basic salt medium with prometryn as the only carbon source

[0051] 1. Implementation method

[0052] (1) Preparation of bacterial suspension

[0053] The purified strain was inoculated into 100 mL of LB liquid medium with a prometryn concentration of 50 mg / L, and was cultured in the dark on a shaking table at 28°C and 150 r / min for 24 h, then was centrifuged at 4000 r / min for 10 min, after centrifugation, the supernatant was removed, and the bacterial suspension was prepared by washing and resuspending with sterilized water, centrifuging again, and continuously washing for 2 times, and finally adding sterilized water to make the concentration of the bacterial solution reach OD 600 =1.0, for standby use

[0054] (2) Liquid degradation experiment of prometryn

[0055] 1 mL of bacterial suspension was taken by a pipette, inoculated into 99 mL of basic salt medium containing prometryn with a concentration of 50 mg / L and sterilized, and a control treatment (1 mL of sterile water) was set, and was cultured in the dark at 28°C and 150 r / min for 5 d, and 5 mL was sampled at the same time point on the 1st day, 3rd day and 5th day, and three repeats were set for each group, then the content of residual prometryn in the culture medium was determined

[0056] (3) Extraction of prometryn

[0057] Take 5 mL of the above culture solution in a centrifuge tube, add 5 mL of ethyl acetate, shake vigorously for 5 min, then centrifuge at 4000 r / min for 10 min, and then stand at room temperature for 10 min. Slowly pour it into a separatory funnel, add 10 mL of ethyl acetate, shake thoroughly. After separation, the organic phase is absorbed by anhydrous sodium sulfate at the bottom of the filter paper and filtered. The filtered organic phase is evaporated to dryness by rotary evaporation at 50°C with a water bath at 80 r / min. Finally, 3.0 mL of n-hexane (chromatographically pure) is added to dissolve prometryn, then n-hexane (chromatographically pure) is sucked by a syringe, and then filtered through a 0.45 μm organic phase filter membrane. The organic phase is transferred into a 2.0 mL Agilent sample bottle for detection

[0058] (4) GC-MS detection

[0059] The sample bottle is loaded, and prometryn is detected by GC-MS. The detection conditions are shown in Table 2.

[0060] Table 2 GC-MS detection conditions

[0061] Item Condition Chromatographic column HP-5MS (30 m x 0.32 mm i.d x 0.25 μm) Injection port temperature 260℃ Column temperature Programmed to 280 degrees Celsius Flow rate 0.8 mL / min Split ratio 2∶1 Injection volume 1 μL

[0062] (5) Draw the standard curve of prometryn

[0063] Standard prometryn solution (10.0 mg / L): accurately weigh 1 mg of dried and constant weight prometryn on an electronic balance in a volumetric flask, then add n-hexane (chromatographically pure) to shake thoroughly and make up to 100 mL, then store in a refrigerator at 4°C for standby. Take 7 15 mL test tubes, add 10.0 mg / mL prometryn standard solution and n-hexane (chromatographically pure) according to Table 3, mix well. Take each concentration of prometryn solution and transfer it into an Agilent sample bottle for detection. Finally, draw the prometryn (GC-MS) standard curve with prometryn concentration as the abscissa and the corresponding peak area as the ordinate.

[0064] Table 3 Prometryn standard solution and n-hexane ratio

[0065] Standard curve sample liquid number 1 2 3 4 5 6 7 Standard propoxur solution (ml) 0 1 2 4 6 8 10 n-Hexane (ml) 10 9 8 6 4 2 0

[0066] (6) Draw the degradation curve of the degrading bacteria

[0067] The bacterial suspension was cultured in the dark on a shaker at 28°C and 150 r / min for 5 days. On the 1st, 3rd, and 5th days, 5 ml of the culture was sampled at the same time point, and the methoxychlor was extracted according to the above method. A sterile blank culture medium was set as a control. The peak area of the methoxychlor in the culture at different time periods was measured by GC-MS, the content of the methoxychlor was calculated, and the degradation efficiency was calculated according to the change of the methoxychlor. Finally, the degradation curve of the degradation bacteria was plotted with time as the horizontal coordinate and the degradation efficiency as the vertical coordinate

[0068] (7) Preparation of the growth curve of the degradation bacteria

[0069] The degradation bacteria SWFU-DH02 were inoculated on LB solid medium and cultured at 28°C for 3 days. Single colonies were picked from the plate and inoculated in 50 ml of LB liquid medium, and cultured for 24 h. 10 ml of the culture was inoculated into 200 ml of LB liquid medium containing 50 mg / L of methoxychlor and LB liquid medium without methoxychlor, respectively. After mixing, 5 ml of the mixture was dispensed into a sterilized test tube, and cultured at 30°C and 150 r / min for 0 h, 2 h, 4 h, 6 h, 8 h, 10 h, 12 h, 14 h, 16 h, 18 h, 20 h, 24 h, 26 h, and 28 h, respectively. Each group had three parallel samples, and a blank control without inoculation was set. The OD 600 value of the blank control was determined by using the LB liquid medium without inoculation as the zero point, and the growth curve of the degradation bacteria was plotted with time as the horizontal coordinate and the OD 600 as the vertical coordinate.

[0070] 2. Experimental results

[0071] (1) The standard curve of the methoxychlor was plotted with the methoxychlor concentration as the horizontal coordinate and the corresponding peak area as the vertical coordinate, as shown in Figure 5 .

[0072] (2) The degradation curve of the methoxychlor is shown in Figure 6 . The degradation efficiency of SWFU-DH02 was the highest on the 3rd day, which was 75.08%, indicating that the strain SWFU-DH02 had a good degradation effect on the methoxychlor

[0073] (3) The growth curve of the degradation bacteria is shown in Figure 7 . As can be seen from the figure, when the LB liquid medium contains the methoxychlor, the OD 600 value of the degradation bacteria SWFU-DH02 is larger, and the growth of the degradation bacteria is faster, indicating that the degradation bacteria can use the methoxychlor as an energy source for growth, so the growth is faster.

[0074] Example 3: Determination of the optimal growth conditions of the degradation bacteria SWFU-DH02

[0075] 1. Experimental Methods

[0076] (1) Effect of pH on the growth of degrading bacteria

[0077] Liquid culture media with different pH values ​​(5.0, 6.0, 7.0, 8.0, 9.0, 10.0) were prepared at suitable salt concentrations. Tricine buffer (pH=7.0) was added to a final concentration of 25–50 mmol / L according to the pH requirements. Inoculation was performed at 1% of the culture medium volume, with three replicates per group, and a blank control without inoculation was included. The cultures were incubated on a shaker at 28°C. After 48 hours of incubation, the absorbance (OD) of the bacterial suspension was measured. 600 value

[0078] (2) Effect of NaCl concentration on the growth of degrading bacteria

[0079] Liquid culture media with different salt concentrations (0%, 1%, 3%, 5%, 7%, 10%) were prepared at pH 7. Inoculation was performed at 1% of the culture medium volume, with three replicates per group, and a blank control without inoculation was included. The cultures were incubated on a shaker at 28°C. After 48 hours of incubation, the absorbance (OD) of the bacterial suspension was measured, using the uninoculated medium as a control. 600 value

[0080] (3) Effect of temperature on the growth of degrading bacteria

[0081] A basal salt culture medium with a salt concentration of 1% and pH 7 was prepared and dispensed into test tubes (5 ml per tube). After sterilization, the culture was inoculated with 1% of the bacterial volume. Three replicates were set up for each group, with uninoculated tubes serving as a control. The culture was incubated with shaking for 48 hours at different temperatures (4℃ (refrigerator), 20℃, 28℃, 37℃, 45℃, 60℃), with the uninoculated culture medium serving as a control. The absorbance (OD) of the bacterial culture was measured. 600 value.

[0082] 2. Experimental Results

[0083] (1) Growth status of degrading bacteria SWFU-DH02 at different pH values Figure 8 As shown. OD values ​​were analyzed by culturing at different pH values ​​for 48 hours. 600 As can be seen from the plot, the OD values ​​of the degrading bacteria at pH=7 are... 600 The maximum value was 0.863, indicating that the optimal pH for the growth of Microbes SWFU-DH02 is 7.

[0084] (2) Growth of degrading bacteria at different salt concentrations, as follows Figure 9 As shown. The OD values ​​of the degrading bacteria after 48 hours of growth at different salt concentrations were compared. 600 The values ​​showed that cell growth was best when the NaCl concentration was 1%, with OD values ​​of [missing value].600 For 0.506, the OD value of the degradation bacteria SWFU-DH02 decreases with the increase of the concentration when the concentration is greater than 1%. Therefore, the optimal growth salt concentration of the degradation bacteria SWFU-DH02 is 1%. 600 600 The OD value of the degradation bacteria SWFU-DH02 decreases with the increase of the concentration when the concentration is greater than 1%. Therefore, the optimal growth salt concentration of the degradation bacteria SWFU-DH02 is 1%.

[0085] (3) The growth of the degradation bacteria at different temperatures is shown in Table 3. By comparing the OD values of the bacteria cultured for 48 hours at different temperatures, it can be seen that the growth of the degradation bacteria SWFU-DH02 is better and better with the increase of the temperature, and the growth is the best at 28℃. When the temperature exceeds 28℃, the growth of the degradation bacteria SWFU-DH02 gradually decreases, and the bacteria basically do not grow when the temperature reaches 60℃. Therefore, the optimal growth temperature of the degradation bacteria SWFU-DH02 is 28℃. Figure 10

[0086] Example 4: Experiment of degradation of the degradation bacteria SWFU-DH02 to the soil of prometryn

[0087] 1. Experimental method

[0088] (1) Preparation of bacterial suspension:

[0089] The purified bacteria SWFU-DH02 were inoculated into 10 mL of LB liquid culture medium and cultured on a shaker at 200 rmp overnight to the logarithmic phase. After centrifugation at 4℃, the bacteria were washed with physiological saline (0.9% NaCl) twice, and the obtained bacteria were used as inoculum and resuspended in MSM liquid medium to make the OD values of all samples consistent (OD 600 =0.5)

[0090] (2) Preparation of prometryn contaminated soil

[0091] The soil sample was taken from the surface layer of soft and hard soil (0-10 cm) in the tree garden of Southwest Forestry University, which had not been applied with any pesticide for more than 5 years. After the soil sample was taken back, it was first placed in a cool and ventilated place for natural air drying, then ground, passed through a 2 mm sieve, and a certain amount of prometryn was dissolved in acetone, then soaked in diatomite to make the prometryn completely absorbed. The soaked diatomite was dried in a fume hood, and then mixed into the soil to make the final concentration of prometryn in the soil 50 mg / kg. 500 g of soil sample was taken, and 100 ml of bacterial suspension (OD 600 =0.5) was inoculated into the soil, stirred uniformly, and cultured in a constant temperature and humidity incubator at 28℃. The soil inoculated with the same amount of sterile water was used as a control, and the water content of the soil was maintained at about 20%. The soil was continuously cultured at 28℃ and in the dark for 15 days, and sampling was performed every 3 days. Three replicates were set for each treatment group

[0092] (3) Extraction of prometryn ​​

[0093] Take 5 g of soil sample, add 10 ml of n-hexane, ultrasonic extraction (90 KHz, 28℃) once, after 2 hours of extraction, centrifuge at 4000 rpm for 10 minutes, take the supernatant, and spin dry at 50℃, 80r / min water bath condition by rotary evaporator. Add 3.0 mL of n-hexane (chromatographic pure) to the rotary evaporator flask to dissolve prometryn, then use a syringe (10 ml) to suck the dissolved solution, filter with an organic phase filter membrane with a pore size of 0.45 μm, transfer the organic phase into a 2.0 mL Agilent sample bottle, and measure

[0094] (4) Degradation efficiency determination

[0095] The method is the same as described in Example 2.

[0096] 2. Experimental results

[0097] The experimental results are shown in Table 4. After 15 days of culture, the degradation efficiency of prometryn in the soil applied with strain SWFU-DH02 reached 78.18%, indicating that strain SWFU-DH02 has good repair effect on prometryn contaminated soil, which provides a theoretical basis for the repair of strain SWFU-DH02 on prometryn in soil.

[0098] Table 4 Degradation efficiency of strain SWFU-DH02 on prometryn in soil

[0099] Time (d) Propoxur degradation efficiency of strain SWFU-DH02 (%) 0 0.00 3 33.52 6 40.18 9 45.56 12 64.53 15 78.18

[0100] The above examples are the preferred embodiments of the present application, but the embodiments of the present application are not limited by the above examples, and the embodiments using the same principles but making some changes, combinations, etc. also belong to the protection scope of the present application.

Claims

1. A strain capable of efficiently degrading the triazine herbicide atrazine, characterized in that, It is Exiguobacterium sp. SWFU-DH02, and was deposited at the China General Microbiological Culture Collection Center (CGMCC) on November 22, 2021, with accession number CGMCC No. 23948.

2. The use of the strain according to claim 1 in the preparation of a bacterial agent for degrading the triazine herbicide pyrazinamide.

3. The use of the strain according to claim 1 in the remediation of natural environments contaminated by the triazine herbicide atrazine or in the preparation of microbial agents for remediation.

4. A highly efficient microbial agent for degrading the triazine herbicide propargite, characterized in that, Contains the microbacterium (Exiguobacterium sp.) SWFU-DH02 as described in claim 1.

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