Burkholderia strain and application thereof

Abstract

The invention belongs to the technical field of microorganisms, and particularly discloses a Burkholderia sp. Strain and application thereof, the classification name of the Burkholderia sp. Strain is Burkholderia sp. Strain is Burkholderia sp. B1, the Burkholderia sp. Strain is preserved in China Center for Type Culture Collection (CCTCC), the address is Wuhan University, Wuhan, China, the preservation number of the Burkholderia sp. Strain is CCTCC NO: M 20251553, and the preservation date is July 8, 2025. The Burkholderia B1 strain has a strong adsorption effect on lead and cadmium metal ions, has the functional characteristics of phosphorus-solubilizing plant growth promotion, soil microbial flora improvement and the like, can be used for heavy metal pollution fixed treatment, plant growth promotion, pathogenic bacteria inhibition and soil microenvironment improvement, is simple in culture condition, is easy to store, is easy for industrial production, and has a wide application prospect. Good development and application prospects are realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of microbial technology, and particularly relates to a Burkholderia strain and application thereof. BACKGROUND

[0002] Lead and zinc resources are extremely rich in southern China. In the process of exploiting and utilizing these resources, there is also a risk of heavy metal pollution of farmland, among which lead and cadmium pollution is the most common. Lead, cadmium and other heavy metals have the characteristics of high toxicity, non-degradability and bioaccumulation, and are long-term enriched in the soil ecosystem, which seriously threatens the sustainable development of agriculture. At present, phytoremediation technology has become an important means to control soil heavy metal pollution, mainly including plant extraction and plant stabilization. Plant extraction technology uses hyperaccumulator plants to continuously absorb and accumulate heavy metals in the soil, and by regularly harvesting the aboveground parts of plants, the soil heavy metal content is gradually reduced; while plant stabilization technology relies on high-tolerant plants to fix heavy metals in the soil or plant roots, significantly reducing their migration to the aboveground parts of plants, thereby effectively blocking the way for heavy metals to enter the food chain.

[0003] However, phytoremediation technology still faces many challenges in practical application. Plant extraction technology is limited by factors such as limited plant biomass, long growth cycle, and long remediation process, and is only suitable for lightly contaminated soil. In contrast, plant stabilization technology has unique value in the remediation of moderately to heavily contaminated soil due to its ability to fix pollutants for a long time, reducing their activity and mobility. There have been extensive research and reports on the use of microbial strains to assist plants in stabilizing heavy metals. CN200710132243.0 discloses a lead and cadmium resistant bacteria and its use in phytoremediation of soil heavy metal pollution, and discloses a Burkholderia strain that is resistant to multiple heavy metals, especially lead and cadmium, has nitrogen fixation and phosphorus solubilization properties, and promotes plant growth. CN200910070348.7 discloses an anti-heavy metal plant growth promoting bacteria preparation and its application method, and discloses a Burkholderia strain that has high resistance to multiple heavy metals, including Pb 2+ , Cd 2+ , Cu²+ and Zn²+, with resistances of 800 mg / L, 1500 mg / L, 150 mg / L and 2500 mg / L, respectively. In addition, strain D54 has plant growth promoting effects such as producing plant growth hormones (IAA), producing 1-amino-1-carboxyl cyclopropane (ACC) deaminase, secreting siderophores, dissolving inorganic phosphate, nitrogen fixation, and antagonizing plant pathogenic bacteria invasion, and other biological control functions. It can significantly increase the biomass of applied plants and improve their disease resistance and stress resistance. However, more microbial strains need to be further explored for heavy metal pollution remediation. SUMMARY

[0004] The technical problem solved by the present application is to provide a strain capable of strengthening plant stable repair technology, especially for plant stabilization of soil lead and cadmium, and the strain can effectively promote the growth and disease resistance of plants under stress environment.

[0005] To solve the above problems, the technical scheme adopted by the present application is as follows:

[0006] The Burkholderia sp. B1 strain of the present application is a soil bacterium isolated from the soil near the tailings of a tungsten-molybdenum mine in Jiujiang City, Jiangxi Province, and is preserved in the China Center for Type Culture Collection (CCTCC) with the preservation number CCTCC NO: M 20251553, the preservation date of July 8, 2025, and the preservation address of Wuhan, China, Wuhan University.

[0007] In the culture process of the above-mentioned Burkholderia sp., the optimal fermentation conditions are as follows: using LB medium for shaking culture, the shaking culture speed is 180 r / min to 220 r / min, the culture temperature is 28℃, and the initial pH is 6 to 7.

[0008] In one aspect of the present application, the present application provides the application of Burkholderia sp. B1 in resisting and stabilizing soil lead and cadmium.

[0009] In one embodiment, the soil includes farmland soil or construction land soil contaminated by lead and cadmium. The strain provided by the present application can strengthen the resistance and stabilization of plants to soil lead and cadmium. This strengthening ability can be measured by the minimum inhibitory concentration of lead and cadmium, the concentration of extractable lead and cadmium, the concentration of lead and cadmium in soil pore water, and the transport coefficient of lead and cadmium in plants.

[0010] In the present application, the minimum inhibitory concentration of heavy metal Pb 2+ of Burkholderia sp. B1 is 2000 mg / L; the minimum inhibitory concentration of heavy metal Cd 2+ of Burkholderia sp. B1 is 250 mg / L. The results of potting soil property determination show that inoculation of Burkholderia sp. B1 has a very good stabilizing and passivating effect on lead and cadmium in soil, and can significantly reduce the bioavailability and mobility of Pb 2+ and Cd 2+ . After 90 days of inoculation, compared with the control group (CK), the concentration of extractable lead and cadmium is reduced by 0.28 times and 0.35 times, respectively; after 90 days of inoculation, compared with the control group (CK), the concentration of lead and cadmium in soil pore water is reduced by 0.35 times and 0.40 times, respectively. The results of determination of lead and cadmium content in potted plants show that, after 90 days of inoculation, compared with the control group (CK), the content of Pb 2+More of it is fixed in the soil, while Cd 2+ It tends to be fixed at the plant roots; Pb 90 days after inoculation 2+ The translocation coefficient (TF, the ratio of heavy metal content in the aboveground parts of plants to that in the underground parts) decreased from 0.48 to 0.25, and Cd... 2+ The transfer coefficient decreased from 0.69 to 0.49.

[0011] In one aspect, the present invention provides the application of Burkholderia B1 in plant growth promotion and disease resistance.

[0012] In one embodiment, the plant is primarily black locust. In this invention, Burkholderia B1 promotes the growth of black locust, increasing seedling height, root length, biomass, and soil available phosphorus concentration.

[0013] In one embodiment, the plant disease resistance is the inhibition of the growth of pathogens, wherein the pathogens are one or more of Fusarium oxysporum, Fusarium graminearum, Fusarium pseudograminearum, Sclerotinia sclerotiorum, and Fusarium asiaticum. Inhibition includes: a) black locust canker caused by Fusarium oxysporum; b) wheat scab caused by Fusarium graminearum; c) wheat stem rot caused by Fusarium pseudograminearum; d) rapeseed sclerotinia rot caused by Sclerotinia sclerotiorum; e) rice bakanae disease caused by Fusarium asiaticum.

[0014] In this invention, compared with the control group (CK), the application of Burkholderia B1 significantly increased the seedling height, root length, and aboveground and underground biomass of plants by 55%, 39%, 67%, and 138%, respectively. Burkholderia B1 also exhibits phosphorus-solubilizing activity, with a D / d value (ratio of phosphorus-solubilizing zone diameter to colony diameter) of 3.17 for organic phosphorus and 1.50 for inorganic phosphorus. Compared with the control group (CK), the concentration of available phosphorus in the rhizosphere soil significantly increased by 171% after 90 days of inoculation. Furthermore, Burkholderia B1 showed a significant inhibitory effect on the pathogen causing black locust canker in plate confrontation tests, and also demonstrated significant antagonistic effects against pathogens causing major diseases in crops such as wheat, rapeseed, and rice.

[0015] Furthermore, this invention has also found that Burkholderia B1 of this invention promotes the relative abundance of beneficial microorganisms in rhizosphere soil. After inoculation with Burkholderia B1, the relative abundance of beneficial microorganisms in rhizosphere soil, including Bacillus sp. and Paenibacillus sp., was significantly increased. Beneficial effects

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] (1) Burkholderia sp. B1 is a type of multifunctional beneficial soil bacteria. This strain has a high tolerance to lead and cadmium. This bacterium is tolerant to multiple heavy metals including lead and cadmium. This invention is applicable to the remediation of soils contaminated with medium to high concentrations of heavy metals. It enhances plant stability and ensures plant survival and growth. This bacterium has a significant antagonistic effect on the main pathogens of various plants (wheat, rapeseed, rice), including black locust. It plays a very important role in improving the soil microenvironment, especially in assisting protective trees and shrubs such as black locust.

[0018] (2) The Burkholderia sp. B1 of the present invention can be artificially cultured, the culture conditions are simple, it is easy to preserve, and it is easy to industrialize and produce, and has good development and application prospects. Attached Figure Description

[0019] Figure 1 The diagram shows the morphological characteristics and phylogenetic tree of the strain in Example 2. In the diagram: a: ​​morphology of the strain; b: phylogenetic tree of the strain.

[0020] Figure 2 The diagram shows the properties of lead and cadmium in the soil in Example 3. In the diagram: a and b: the concentration ratio of extractable lead and cadmium in the soil, representing the bioavailability of lead and cadmium; c and d: the concentration of lead and cadmium in the pore water of the soil, representing the mobility of lead and cadmium in the soil.

[0021] Figure 3 The graph shows the absorption and translocation coefficients of lead and cadmium in plants in Example 3. In the graph: a: the amount of lead in the plants after 30, 60 and 90 days after inoculation; b: the amount of cadmium in the plants after 30, 60 and 90 days after inoculation.

[0022] Figure 4 The figure shows the growth results of the plant in Example 4. In the figure: a: seedling height and root length of the plant; b: biomass of the above-ground and underground parts of the plant.

[0023] Figure 5 This is a plate confrontation diagram of strain B1 inhibiting plant pathogens in Example 5. In the diagram: a: ​​Fusarium oxysporum (black locust canker); b: Fusarium graminearum (wheat scab); c: Fusarium pseudograminearum (wheat stem base rot); d: Sclerotinia sclerotiorum (rapeseed sclerotinia); e: Fusarium alpha-Asianis (rice bakanae disease).

[0024] Figure 6 The diagram shows the soil physicochemical properties and soil microbial community structure in Example 4. In the diagram: a: ​​available phosphorus, available nitrogen, and available potassium; b: relative abundance of dominant microbial species in the rhizosphere soil 30, 60, and 90 days after inoculation.

[0025] In this invention, "Burkholderia sp. B1", "strain B1", and "Burkholderia sp. B1" all refer to the Burkholderia strain with accession number CCTCC NO: M 20251553 in this invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. Unless otherwise specified, the equipment and reagents used in the embodiments and experimental examples are commercially available. Unless otherwise stated, all reagents used in this invention are analytical grade reagents. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0027] The main test materials involved in this invention are as follows:

[0028] (1) Main reagents

[0029] Lead nitrate, cadmium chloride, calcium chloride, agar, yeast extract, tryptone, sodium chloride, 95% ethanol.

[0030] (2) Culture medium

[0031] NA medium, LB medium, Monkina organic phosphorus medium, inorganic phosphorus medium, PDA medium.

[0032] All of the above materials are from suppliers in the market and can be purchased through commercial channels.

[0033] Example 1: Screening of bacterial strains

[0034] (1) Tolerance to heavy metals

[0035] Freshly collected soil samples were continuously diluted with sterile water to a concentration of 10. -4 10 -5 10 -6 Soil suspensions were prepared at different concentrations; after standing, 100 μL of each concentration dilution was spread onto LB solid medium (tryptone 10 g / L; yeast extract 5 g / L; sodium chloride 10 g / L); strains with different appearances were selected and continuously passaged on LB medium (at least three generations) to obtain pure microbial cultures.

[0036] Pb was prepared using Pb(NO3)2 and CdCl2·5H2O reagents. 2+ The concentration was 800 mg / L, and Cd 2+A 100 mg / L heavy metal aqueous solution was used to prepare NA solid medium, which was used for preliminary screening of soil microbial strains tolerant to heavy metals lead and cadmium. The isolated bacterial pure cultures were inoculated onto NA solid medium containing lead and cadmium and cultured overnight at 30°C in a constant temperature incubator. The colony growth on the blank medium was used as a control, and bacteria that could grow on heavy metal medium plates and had observable colony size were selected as candidate strains tolerant to heavy metals.

[0037] (2) Phosphorus solubility

[0038] Pure cultures of lead- and cadmium-tolerant bacteria described in (1) were inoculated onto the Mongkina organic (inorganic) phosphorus medium. Three inoculation sites were arranged on the same plate for each strain, which served as three replicates. After culturing in an incubator for 5-7 days, the microorganisms that showed a clear zone on the plate were those with phosphorus-solubilizing ability. The diameter (d) of the strain and the diameter (D) of the clear zone were measured, and D / d was calculated as the basis for judging the phosphorus-solubilizing ability of different microbial strains. Finally, the lead- and cadmium-tolerant phosphorus-solubilizing strain B1 was obtained through screening, and its phosphorus-solubilizing ability is shown in Table 1.

[0039] (3) Minimum inhibitory concentration of lead and cadmium to which strain B1 is tolerant

[0040] Microbial agar plates were prepared on LB solid medium supplemented with different concentrations of Pb(NO3)2 and CdCl2·5H2O. The growth of the strain was significantly inhibited, and no visible strain could be formed. The minimum metal ion concentration (MIC) is the lowest concentration at which the strain can grow, and is therefore the minimum inhibitory concentration (MIC) for that metal. Testing showed that the MICs for lead and cadmium in strain B1 were Pb(NO3)2 and CdCl2·5H2O, respectively. 2+ 2000 mg / L; Cd 2+ 250 mg / L, see Table 1. In addition, this invention also compared the heavy metal lead and cadmium tolerance of two other Burkholderia strains (NL-3 and NL-7), with minimum inhibitory concentrations of Pb and Pc respectively. 2+ 1600 mg / L and 1650 mg / L; Cd 2+ 210 mg / L and 150 mg / L. Further results indicate that Burkholderia spp. possesses corresponding lead-cadmium tolerance, and the minimum inhibitory concentration range is approximately: Pb 2+ : Between 1500 mg / L and 2500 mg / L, and Cd 2+ The concentrations ranged from 150 mg / L to 300 mg / L, further demonstrating that strain B1 exhibits superior tolerance to heavy metals such as lead and cadmium.

[0041]

[0042] Example 2 Molecular biological identification of the strain

[0043] (1) Morphological characteristics of the strain

[0044] Single colonies of strain B1 were streaked onto LB agar plates. The plates were inverted and incubated overnight at 30°C until opaque, moist, raised, pale yellow colonies formed. Figure 1 .

[0045] (2) Identification of 16S rRNA in strains

[0046] Genomic DNA was extracted from strain B1 using a bacterial genomic DNA extraction kit (Shanghai Jereh Biotechnology Co., Ltd.). Using this DNA as a template, the 16S rRNA fragment of the strain was amplified using universal primers for bacterial 16S rRNA (27F, 1492R). After sequencing, Blast homology was compared with the nucleic acid database in NCBI (www.ncbi.nlm.nih.gov / Blast). A phylogenetic tree of the strain was constructed using the proximity binding method in MEGA 5.0 software. Figure 1 As shown, this bacterium belongs to the genus *Burkholderia* and clusters similarly with many other bacteria within this genus. Therefore, this strain is tentatively named *Burkholderia sp.*, and laboratory-labeled as B1. The selected *Burkholderia sp.* B1 was deposited at the China Center for Type Culture Collection (CCTCC) with accession number CCTCC NO: M 20251553, deposit date July 8, 2025, and address Wuhan University, Wuhan, China.

[0047] Example 3: Application of strain B1 in resisting and stabilizing lead and cadmium in soil

[0048] (1) Effects of Burkholderia B1 on soil lead / cadmium bioavailability

[0049] The impact of inoculated strain B1 on the bioavailability of lead and cadmium was measured by the percentage of extractable lead and cadmium in the soil.

[0050] To determine the total and extractable contents of lead and cadmium in rhizosphere soil samples, the soil samples were mixed with CaCl2 solution and shaken or agitated. After extraction, the soil sample solution was separated by centrifugation or filtration, and the solution was analyzed using inductively coupled plasma atomic emission spectrometry (ICP-AES). The extractable lead / cadmium ratio was calculated using the following formula:

[0051] Extractable lead (or cadmium) content percentage = (Available lead (or cadmium) content in soil / Total lead (or cadmium) content in soil) × 100%

[0052] Ninety days after vaccination, compared with the control group, the proportions of extractable lead and cadmium concentrations decreased by 0.28 times (see...). Figure 2 a) and 0.35 times (see Figure 2 (b) The results showed that inoculation with strain B1 reduced the bioavailability of lead and cadmium in the soil.

[0053] (2) Effects of Burkholderia B1 on soil lead / cadmium mobility

[0054] The effect of inoculated strain B1 on lead and cadmium mobility was measured by the content of lead and cadmium in soil pore water.

[0055] Soil pore water sampling: Soil pore water samples were collected twice, one week before sampling at each plant growth stage. Each treatment group included three replicates. The corresponding samples from the two collections were combined to form the soil pore water sample for the current plant growth stage. Soil pore water was collected using a soil water sampler (Rhizon, 19.21.22F, MOM model, 5cm, Netherlands). The collected soil pore water was acidified and digested with 65% nitric acid solution (HNO3), and the digested solution was analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES). The measured results were used as the Pb content in the soil pore water. 2+ and Cd 2+ The concentration of lead and cadmium in the soil, i.e., the mobility of lead and cadmium in the soil.

[0056] Ninety days after inoculation, compared with the control group, Pb in soil pore water was... 2+ and Cd 2+ The concentrations decreased by 0.35 times ( Figure 2 c) and 0.40 times ( Figure 2 (d). The results indicate that inoculation with strain B1 reduced the mobility of lead and cadmium in the soil.

[0057] (3) Effect of strain B1 on lead / cadmium properties in Robinia pseudoacacia

[0058] To determine the lead and cadmium content in the aboveground and underground parts of plants, the plant tissues were pulverized, finely ground, and sieved (using a 100-mesh sieve). Three replicate samples with the same treatment were uniformly mixed to determine the lead and cadmium content in the plant tissues separately. 0.1 g of the treated plant tissue was digested in a sealed container with concentrated nitric acid (5 mL) and perchloric acid (1 mL) until a clear solution was obtained. The solution was analyzed using inductively coupled plasma atomic emission spectrometry (ICP-AES).

[0059] The formula for calculating the translocation coefficient of lead and cadmium in plants is as follows:

[0060] Translocation factor (TF) = Heavy metal content in aboveground parts of plant / Heavy metal content in underground parts of plant

[0061] The above test results were used to measure the stabilizing effect of plants on soil lead and cadmium. The results showed that 90 days after inoculation, compared with the control (CK), Pb... 2+ More of it is fixed in the soil, while Cd 2+ It is more likely to be fixed to the plant roots, and Pb 2+ The TF value decreased from 0.48 to 0.25, and Cd 2+ The TF value decreased from 0.69 to 0.49, see Figure 3 a and Figure 3 b.

[0062] Example 4: Growth-promoting application of strain B1

[0063] (1) Material preparation

[0064] Black locust seeds were surface-sterilized and germination-treated before sowing (3 days, 20℃, 60% relative humidity). Pot experiments were conducted in a greenhouse, using topsoil (0-15cm) from farmland. The soil was sieved (5mm x 5mm) to remove impurities such as rocks and plant tissues, and then autoclaved to inactivate plant seeds, soil animals, and microorganisms. After sterilization, heavy metal soil preparation was performed. A mixed aqueous solution containing Pb(NO3)2 and CdCl2·5H2O was sprayed onto the soil. The initial and treated soils were aged in the dark for approximately three weeks; soil background values ​​are shown in Table 2. The Pb content of the treated soil... 2+ and Cd 2+ The final stable content was 268.84 ± 10.23 mg·kg. -1 and 63.06 ± 2.82 mg·kg -1 (The heavy metal content of the prepared soil is based on the Chinese Soil Pollution Risk Control Standard GB36600-2018). After the prepared soil has air-dried naturally, vermiculite and perlite are added in a ratio of 3:1:1. Each pot is filled with 2 kg of the mixed soil (pot size: 18 cm in diameter, 23 cm in depth).

[0065]

[0066] (2) Pot experiment design

[0067] The experiment included two treatment groups: Robinia pseudoacacia planted alone in heavy metal-contaminated soil (CK); and Robinia pseudoacacia planted in heavy metal-contaminated soil and inoculated with Burkholderia bacillus B1 (strain B1). Robinia pseudoacacia seeds were cultured in disposable plastic seedling cups, with 2-3 seeds placed in each cup. After approximately 15 days, a healthy seedling was selected for transplanting. Three replicates were collected for each treatment at three different stages of plant growth, for a total of 18 potted plants (n = 2 × 3 × 3 = 18). A liquid culture of strain B1 was prepared, and the optical density (OD) of the liquid culture at 600 nm was adjusted. 600 The concentration was 0.8-1.2 (UV spectrophotometer, UV2600). After transplanting the seedlings, inoculation was carried out by diluting the prepared bacterial fermentation broth 100 times and watering it around the plants in the B1 treatment group, using 60 mL per pot. To ensure successful inoculation, a second inoculation with the same dosage was performed 3 days after the first inoculation.

[0068] (3) Growth-promoting effects

[0069] Plant samples were collected at 30, 60, and 90 days after emergence. Plant height and diameter at ground level were measured before each sample collection. All plants were divided into aboveground parts (stems and leaves) and underground parts (roots). Plant tissues were dried at 110℃ and blanched for 30 minutes. After ensuring constant weight, the tissues were weighed as indicators of plant biomass. See [link to relevant documentation] Figure 4 Ninety days after inoculation, compared with the control group, the seedling height, root length, aboveground and belowground biomass of Robinia pseudoacacia in polluted soil were significantly increased by 55%, 39%, 67% and 138%, respectively.

[0070] Example 5: Antagonistic effect of strain B1 against pathogens

[0071] Strain B1 was inoculated into LB liquid medium and fermented at 30℃ and 180 rpm for 48 h to obtain a pure liquid culture of strain B1. A plate confrontation test of the strain's disease resistance was conducted using solid potato juice (PDA) medium. Plant pathogens were inoculated in the center of the plate, and sterilized filter paper discs were placed at four positions. 2.5 μL of the prepared liquid culture of strain B1 was then inoculated onto each disc and incubated at 25℃. The tested plant pathogens were: *Fusarium oxysporum* (black locust canker), *Fusarium graminearum* (wheat scab), *Fusarium pseudograminearum* (wheat stem rot), *Sclerotinia sclerotiorum* (rapeseed sclerotinia rot), and *Fusarium asiaticum* (rice bakanae disease). The results are as follows: Figure 5As shown, strain B1 not only exhibits significant antagonistic effects against the pathogens causing canker in black locust trees and shrubs, but also effectively antagonizes pathogens causing major diseases in crops such as wheat, rapeseed, and rice. The antagonistic rates against each pathogen are shown in Table 3.

[0072]

[0073] Example 6: Effects of strain B1 on soil nutrients and microbial community

[0074] In Example 3, while collecting plants at each growth stage, rhizosphere soil samples were also collected. The soil around the plant roots was carefully cleaned with a brush. One sample of soil was immediately frozen at -80°C for microbial sequencing analysis; another sample of soil was sieved through a 20-mesh sieve, air-dried, and used for soil property determination.

[0075] See Figure 6 Ninety days after inoculation, compared with the contaminated soil group (CK), the available phosphorus content in the soil was significantly increased by 171%; the relative abundance of Bacillus sp. and Paenibacillus sp. in the rhizosphere soil was also significantly increased. Furthermore, compared with the two groups of Burkholderia NL3 and NL7, strain B1 of this invention was more effective in increasing the abundance of beneficial microorganisms Bacillus sp. and Paenibacillus sp. (P<0.05), see [link to relevant documentation]. Figure 6 .

[0076] In summary, the Burkholderia strain involved in this invention not only tolerates and adsorbs high concentrations of heavy metals such as lead and cadmium, but also possesses characteristics such as phosphorus solubilization, plant growth promotion, and improvement of beneficial microbial communities in the soil. The application of this strain can not only enhance the remediation effect of phytostabilization technology, but also improve the survival rate of plants in extremely polluted environments, thus having significant practical application value for achieving long-term benefits in soil remediation.

[0077] The above description, in conjunction with specific embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all such deductions or substitutions should be considered to fall within the scope of protection defined by the claims submitted herein.

Claims

1. A Burkholderia strain, characterized in that, The strain is Burkholderia sp. B1, deposited on July 8, 2025 at the China Center for Type Culture Collection, Wuhan University, Wuhan, China, accession number CCTCC NO: M 20251553.

2. The Burkholderia strain according to claim 1, characterized in that, The strain is a soil bacterium tolerant to lead and cadmium, and its minimum Pb content is [not specified]. 2+ The antibacterial concentration is 2000 mg / L, and the minimum Cd is... 2+ The antibacterial concentration is 250 mg / L.

3. A Burkholderia inoculant, characterized in that, The bacterial agent contains Burkholderia B1 as described in claim 1.

4. The application of a strain according to claim 1, or a microbial agent according to claim 3, in resisting and stabilizing lead and cadmium in soil.

5. The application according to claim 4, characterized in that, The application is any one of the following ①②: ① Application of strain B1 to reduce the bioavailability and mobility of lead and cadmium in soil; ② Application of strain B1 in reducing the translocation coefficient of lead and cadmium in plants.

6. The application of the strain according to claim 1 or the microbial agent according to claim 3 in promoting plant growth in lead-cadmium contaminated soil.

7. The application according to claim 6, characterized in that, The promotion of plant growth is any one of the following ①②: ① Application of strain B1 in improving plant seedling height, root length and biomass; ② Application of strain B1 in increasing the concentration of available phosphorus in soil.

8. The application of a strain according to claim 1 or an inoculant according to claim 3 in improving soil by increasing the relative abundance of beneficial microbial genera.

9. The application according to claim 8, characterized in that, The beneficial soil microorganisms mentioned include Bacillus sp. and Paenibacillus sp.

10. The application of the strain according to claim 1 or the inoculant according to claim 3 in inhibiting plant pathogens, characterized in that, The pathogenic bacteria are one or more of the following: Fusarium oxysporum, Fusarium graminearum, Fusarium pseudograminearum, Sclerotinia sclerotiorum, and Fusarium asiaticum.

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