New Burkholderia cepacia HSP-21 for dissolving phosphorus and solidifying heavy metals and application of new Burkholderia cepacia HSP-21

Abstract

The invention belongs to the technical field of microorganisms, and discloses a novel Burkholderia cepacia HSP-21 capable of dissolving phosphorus and solidifying heavy metals and an application of the novel Burkholderia cepacia HSP-21. The novel burkholderia cepacia disclosed by the invention is Burkholderia cepacia HSP-21, and the preservation number of the novel burkholderia cepacia is CCTCC (China Center for Type Culture Collection) NO: M 20251344; the strain is preserved in China Center for Type Culture Collection on June 12, 2025, and the preservation address is Wuhan University, Wuhan, Hubei, China. The strain disclosed by the invention has relatively strong phosphorus dissolving activity, heavy metal removal capacity and curing effect, and can effectively inhibit migration and transformation of heavy metals, so that long-term stabilization of the heavy metals is realized. The strain can be applied to environmental remediation and heavy metal pollution treatment.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of microbial technology, and in particular to a new Burkholderia cenocepacia HSP-21 for dephosphorization and heavy metal solidification and its application. BACKGROUND

[0002] Heavy metal pollution is a major challenge in global environmental governance, mainly from industrial emissions, wastewater discharge and agricultural activities. Heavy metals such as lead (Pb), mercury (Hg) and cadmium (Cd) not only pollute soil and water, but also affect human health through the food chain, and long-term exposure can cause central nervous system damage, cancer and reproductive problems. Heavy metals are cumulative, toxic and difficult to degrade, and can exist in soil for a long time, hindering the absorption of essential nutrients by plants and threatening crop growth. At the same time, heavy metals damage the soil ecosystem, inhibit microbial activity, affect organic matter decomposition, and further exacerbate soil degradation.

[0003] In recent years, soil microbial remediation technology has gradually become the main pollution control method due to its environmental protection, low cost and significant effect. Microorganisms effectively reduce the bioavailability of heavy metals through mechanisms such as biosorption, bioreduction, bioaccumulation and biomineralization, reducing their toxicity. In particular, the microbial-induced biomineralization process promotes the reaction of metals with inorganic compounds (such as phosphates, sulfides, carbonates) to form insoluble minerals, stabilizing heavy metals and reducing their migration and bioavailability, with strong environmental persistence. Among them, the microbial-induced phosphate precipitation (MIPP) technology has significant advantages. Phosphate minerals have low solubility and can effectively immobilize lead and cadmium, preventing their migration. However, MIPP technology still faces limitations in microbial growth and removal capacity in high metal concentration environments. SUMMARY

[0004] The present application aims to overcome the shortcomings of the prior art and provide a new Burkholderia cenocepacia HSP-21 for dephosphorization and heavy metal solidification and its application. This strain has high heavy metal tolerance and strong heavy metal mineralization ability, can reduce the mobility and bioavailability of heavy metal ions, and has important significance for restoring the soil ecological environment.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows: In a first aspect, the present application provides a new Burkholderia cenocepacia, which is Burkholderia cenocepacia HSP-21, has a preservation number of CCTCC NO: M20251344, and was preserved in the China Center for Type Culture Collection on June 12, 2025, at an address of Wuhan University, Wuhan, Hubei, China.

[0006] The present application screens and isolates the Burkholderia cenocepacia HSP-21 strain from collected mine soil, has strong phosphorus solubilization activity, heavy metal removal capacity and solidification effect. The strain has excellent removal and solidification effects on heavy metal ions such as Pb 2+ and Cd 2+ , respectively promotes Pb and Cd to form minerals such as Pb5(PO4)3Cl (Ksp=-76.8), Cd-Ca5(PO4)3OH, Cd5(PO4)3OH (Ksp=-42.49), and Cd5(PO4)3Cl (Ksp=-49.66), effectively inhibits the migration and transformation of heavy metals, and further realizes the long-term stabilization of heavy metals.

[0007] In a second aspect, the present application provides the cell body, fermentation broth, supernatant and / or intracellular substance of the new Burkholderia cenocepacia of the first aspect.

[0008] In a third aspect, the present application provides a heavy metal solidification agent or removal agent, which comprises the new Burkholderia cenocepacia of the first aspect or the cell body, fermentation broth, supernatant and / or intracellular substance of the second aspect.

[0009] As a preferred embodiment of the heavy metal solidification agent or removal agent of the present application, the heavy metal is at least one of copper, cadmium, lead, zinc, nickel, arsenic, chromium, and molybdenum.

[0010] As a preferred embodiment of the heavy metal solidification agent or removal agent of the present application, the concentration of the heavy metal is 0-40 g / L.

[0011] In a fourth aspect, the present application provides a phosphorus solubilization active agent for insoluble phosphorus, which comprises the new Burkholderia cenocepacia of the first aspect or the cell body, fermentation broth, supernatant and / or intracellular substance of the second aspect.

[0012] As a preferred embodiment of the phosphorus solubilization active agent for insoluble phosphorus of the present application, the insoluble phosphorus is at least one of magnesium phosphate, aluminum phosphate, iron phosphate, and ferrous phosphate.

[0013] As a preferred embodiment of the phosphorus solubilization active agent for insoluble phosphorus of the present application, the concentration of the insoluble phosphorus is 0-10 g / L.

[0014] In a fifth aspect, the application provides application of the Burkholderia cenocepacia of the first aspect, the cell mass, the fermentation broth, the supernatant and / or intracellular substance of the second aspect, the heavy metal solidifying agent or removal agent of the third aspect, or the phosphorus-dissolving active agent of the insoluble phosphorus of the fourth aspect in heavy metal pollution treatment.

[0015] In a sixth aspect, the application provides application of the Burkholderia cenocepacia of the first aspect, the cell mass, the fermentation broth, the supernatant and / or intracellular substance of the second aspect, the heavy metal solidifying agent or removal agent of the third aspect, or the phosphorus-dissolving active agent of the insoluble phosphorus of the fourth aspect in wastewater and / or soil heavy metal remediation.

[0016] Compared with the prior art, the application has the following beneficial effects: (1) The Burkholderia cenocepacia HSP-21 strain of the application can tolerate high concentrations of heavy metals such as lead and cadmium and has high phosphorus-dissolving capacity, and exhibits excellent removal capacity in heavy metal pollution remediation. The strain can convert heavy metals into stable mineral forms such as Pb5(PO4)3Cl, Cd5(PO4)3OH, Cd5(PO4)3Cl and Cd-Ca5(PO4)3OH through biomineralization, effectively reducing the bioavailability and toxicity of heavy metals, and realizing long-term stabilization, so as to achieve the goal of environmental remediation and heavy metal pollution treatment.

[0017] (2) The Burkholderia cenocepacia HSP-21 strain of the application has high tolerance to heavy metals, so that it can continuously and effectively remove and solidify heavy metals throughout the growth process.

[0018] (3) The Burkholderia cenocepacia HSP-21 strain of the application has strong heavy metal mineralization capacity, can effectively convert heavy metals into insoluble minerals, and reduce the bioavailability thereof; the strain has strong soluble phosphorus release capacity, which helps to improve the immobilization effect of heavy metals; the strain has significant advantages in enhancing heavy metal tolerance and soluble phosphorus release capacity; and the strain has stronger stability and efficiency in heavy metal remediation.

[0019] (4) The Burkholderia cenocepacia HSP-21 strain of the application is applied in wastewater and soil heavy metal remediation, which is simple to operate, low in cost, and widely applicable, and does not cause secondary pollution or damage to plants and the environment, thereby providing an environmentally friendly and efficient solution for heavy metal pollution treatment and soil reclamation. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 Figure 1 is a diagram showing the phosphorus-dissolving effect of the Burkholderia cenocepacia HSP-21 strain; Figure 2Phylogenetic tree of Burkholderia glumae HSP-21 strain Figure 3 Tolerance of Burkholderia glumae HSP-21 strain to heavy metal Pb Figure 4 Tolerance of Burkholderia glumae HSP-21 strain to heavy metal Cd Figure 5 Soluble phosphorus release capacity of Burkholderia glumae HSP-21 strain Figure 6 Removal rate of heavy metal Pb in simulated wastewater by fermentation broth of Burkholderia glumae HSP-21 strain Figure 7 Removal rate of heavy metal Cd in simulated wastewater by fermentation broth of Burkholderia glumae HSP-21 strain Figure 8 Solidification effect of supernatant of Burkholderia glumae HSP-21 strain on heavy metal Pb Figure 9 Removal capacity of supernatant of Burkholderia glumae HSP-21 strain on heavy metal Pb Figure 10 Solidification capacity (a) and effect (b) of fermentation broth of Burkholderia glumae HSP-21 strain on heavy metal Cd under different Cd concentrations Figure 11 Solidification capacity and removal rate of fermentation broth of Burkholderia glumae HSP-21 strain on heavy metal Cd when Mg3(PO4)2 is used as phosphorus source Figure 12 Solidification effect of fermentation broth of Burkholderia glumae HSP-21 strain on heavy metal Cd when Mg3(PO4)2 is used as phosphorus source Figure 13 Removal rate of fermentation broth of Burkholderia glumae HSP-21 strain on heavy metal in actual wastewater Figure 14 Removal rate of fermentation broth of Burkholderia glumae HSP-21 strain on heavy metal in actual wastewater Figure 15 Removal rate of fermentation broth of Burkholderia glumae HSP-21 strain on heavy metal Cd in different growth periods DETAILED DESCRIPTION

[0021] In order to better illustrate the purposes, technical solutions and advantages of the present application, the present application will be further described below in combination with specific examples. Those skilled in the art should understand that the specific examples described herein are only used to explain the present application, and are not used to limit the present application.

[0022] Unless otherwise specified, the experimental methods used in the examples are conventional methods; the materials and reagents used are commercially available unless otherwise specified. The following formulation for tricalcium phosphate liquid culture medium is: 10.0g glucose, 0.3g sodium chloride, 0.3g magnesium sulfate, 0.03g manganese sulfate, 0.5g ammonium sulfate, 0.3g potassium chloride, 0.03g ferrous sulfate, 10.0g calcium phosphate, and 1000mL distilled water, pH 7.0-7.5. For tricalcium phosphate solid culture medium, 2.0% (m / v) agar powder needs to be added; all culture media are sterilized at 121℃ and 110kPa for 30 minutes before use.

[0023] Example 1: Screening and identification of Burkholderia cepacia HSP-21 (1) Screening Soil samples were collected from a mining area in Chenzhou, Hunan Province, with high levels of heavy metal contamination, using sterile sampling bags. The collected soil samples were stored at -20°C. Before the experiment, 5g of soil was thawed to room temperature and added to 45mL of sterile water. The mixture was shaken at 200rpm for 30 minutes to prepare a soil suspension. Based on a 2% addition rate, the soil suspension was inoculated into tricalcium phosphate liquid medium and cultured for 4 to 7 days. Colonies were then isolated using plate spreading and spot purification methods until pure single colonies were obtained.

[0024] Colonies with a clear zone were selected and purified through multiple three-zone streak purification processes to obtain bacteria capable of phosphate solubilization. When cultured on solid plates, these colonies formed round, well-defined colonies with smooth, regular edges. The colony surface was moist, glossy, and smooth, and the overall structure was opaque. Figure 1 As shown.

[0025] (2) Identification The selected strain was amplified by PCR using primers 27F and 1492R, and the amplification product was sequenced to obtain the 16S rDNA sequence of the strain. The sequence is as follows: .

[0026] Microbial phylogenetic trees were constructed using BLAST alignment and MEGA software (see [link to BLAST]). Figure 2 The strain was ultimately identified as *Burkholderia cenocepacia*. This strain was named *Burkholderia cenocepacia HSP-21* and deposited on June 12, 2025, at the China Center for Type Culture Collection (CCTCC), accession number CCTCC NO: M 20251344, located at Wuhan University, Wuhan, Hubei Province, China.

[0027] Example 2: Heavy metal tolerance test of Burkholderia neocarpa HSP-21 (1) 100 μL of sterile lead (Pb) gradient concentration solutions (concentrations of 0 mg / L, 500 mg / L, 1500 mg / L, 3000 mg / L, 6000 mg / L, 10000 mg / L, 20000 mg / L, and 40000 mg / L, respectively) were spread on the surface of tricalcium phosphate solid medium. Subsequently, Burkholderia neocarpa HSP-21 bacterial suspension in the logarithmic growth phase was simultaneously spread on the same plate. After incubation at 28℃ for 6 days, the growth status of the strain was observed and recorded.

[0028] The results of the experiment on the tolerance of Burkholderia cepacia HSP-21 strain to heavy metals Pb and Cd are as follows: Figure 3 As shown, when the concentration of sterile lead (Pb) is 40,000 mg / L, the growth of Burkholderia neonavixii HSP-21 strain is unrestricted, and it has strong tolerance to the heavy metal lead.

[0029] (2) 100 μL of sterile cadmium (Cd) solutions at gradient concentrations (0 mg / L, 1500 mg / L, 3000 mg / L, 6000 mg / L, 10000 mg / L, 20000 mg / L, and 40000 mg / L) were spread onto the surface of tricalcium phosphate solid medium. Subsequently, Burkholderia neonosae HSP-21 bacterial suspensions in the logarithmic growth phase were simultaneously spread onto the same plate. After incubation at 28°C for 6 days, the growth status of the strains was observed and recorded.

[0030] The results of the experiment on the tolerance of Burkholderia cepacia HSP-21 strain to heavy metal Cd are as follows: Figure 4 As shown, when the concentration of sterile cadmium (Cd) is 40,000 mg / L, the growth of Burkholderia neonavicularis HSP-21 strain is limited, indicating strong tolerance to the heavy metal cadmium.

[0031] Example 3: Phosphate-solubilizing performance test of Burkholderia neonata HSP-21 Take the activated Burkholderia cepacia HSP-21 bacterial culture and add it to tricalcium phosphate liquid medium at an inoculation rate of 2% (volume ratio). Incubate at 28℃ for 100 h and observe the changes in phosphorus content in the fermentation broth.

[0032] like Figure 5 As shown, the phosphorus content in the fermentation broth increased with increasing culture time from 0h to 80h, reaching its highest value at 80h. This indicates that the *Burkholderia cepacia* HSP-21 strain has a strong ability to dissolve insoluble phosphorus.

[0033] Example 4: Heavy Metal Removal Capacity Test of *Burkholderia neocarinatum* HSP-21. 1 mL of activated *Burkholderia neocarinatum* HSP-21 bacterial culture was inoculated into 50 mL of beef extract peptone liquid medium. After incubation at 28°C for 24 hours, it was transferred to tricalcium phosphate liquid medium at a 2% (v / v) inoculation rate. After incubation at 28°C for 6 days, the fermentation broth was transferred to sterile empty conical flasks. Subsequently, sterile heavy metal stock solutions were added to achieve lead concentrations of 1800 mg / L and cadmium concentrations of 500 mg / L. After incubation at 28°C for a period of time, the supernatant was centrifuged, filtered, and diluted. The changes in heavy metal content in the supernatant were determined using ICP-OES.

[0034] like Figure 6 As shown, the removal rate of lead by Burkholderia neonosa HSP-21 strain in simulated wastewater was 1800 mg / L. This strain can completely remove lead in the early stage of cultivation.

[0035] like Figure 7 As shown, the removal rate of 500 mg / L Cd by Burkholderia neonosae HSP-21 strain in simulated wastewater is shown. With the increase of culture time, the removal of lead metal by this strain increases, and it can eventually remove about 90% of the cadmium metal.

[0036] Example 5: Immobilization ability and effect of supernatant of *Burkholderia neocarpinus* HSP-21 on heavy metal Pb. 1 mL of activated *Burkholderia neocarpinus* HSP-21 culture was inoculated into 50 mL of beef extract peptone liquid medium. After incubation at 28°C for 24 hours, it was transferred to tricalcium phosphate liquid medium at a 2% (v / v) inoculation rate. After incubation at 28°C for 6 days, the supernatant (0.22 μm filtered fermentation broth) was transferred to a sterile empty conical flask; subsequently, sterile heavy metal mother liquor was added to achieve a lead concentration of 1500 mg / L. After incubation at 28°C until heavy metal removal equilibrium was reached (the heavy metal concentration in the supernatant no longer changed), the sample was freeze-dried and ground, and then tested using an X-ray diffractometer (XRD).

[0037] like Figure 8 and 9 As shown, the supernatant of *Burkholderia neonavi* strain HSP-21 can efficiently remove lead at 1500 mg / L Pb. Furthermore, the supernatant of this bacterium reacts with Pb to form Pb5(PO4)3Cl minerals with a low solubility product constant (Ksp). This result confirms that this strain has strong solidification and removal capabilities for lead.

[0038] Example 6: Effect of Burkholderia neocarpinus HSP-21 fermentation broth on the immobilization of different concentrations of heavy metal Cd. 1 mL of activated Burkholderia neocarpinus HSP-21 bacterial culture was inoculated into 50 mL of beef extract peptone liquid medium. After incubation at 28°C for 24 hours, it was transferred to tricalcium phosphate liquid medium at a 2% (v / v) inoculation rate. After incubation at 28°C for 6 days, sterile heavy metal stock solution was added to achieve cadmium concentrations of 800 and 1200 mg / L, respectively. After incubation at 28°C until heavy metal removal equilibrium was reached (the heavy metal concentration in the fermentation broth no longer changed), the samples were freeze-dried and ground, and then tested using X-ray diffraction (XRD).

[0039] like Figure 10 As shown in (a), the fermentation broth of Burkholderia cepacia HSP-21 strain can solidify Cd of different concentrations, indicating that this strain can achieve efficient removal of Cd.

[0040] like Figure 10 As shown in (b), the fermentation broth of Burkholderia cepacia HSP-21 strain solidifies Cd of different concentrations, indicating that the strain can generate Cd-Ca5(PO4)3OH mineral with a low solubility product constant (Ksp) after reacting with Cd.

[0041] Example 7: Test on the removal and solidification capacity of heavy metals by fermentation broth of *Burkholderia neonavi* HSP-21 using Mg3(PO4)2 as a phosphorus source. 1 mL of activated *Burkholderia neonavi* HSP-21 bacterial culture was inoculated into 50 mL of beef extract peptone liquid medium. After incubation at 28°C for 24 hours, it was transferred to Mg3(PO4)2 liquid medium (formulation: 10.0 g glucose, 0.3 g sodium chloride, 0.3 g magnesium sulfate, 0.03 g manganese sulfate, 0.5 g ammonium sulfate, 0.3 g potassium chloride, 0.03 g ferric sulfate, 10.0 g magnesium phosphate, 1000 mL distilled water, pH 7.0-7.5) at a 2% (v / v) inoculation rate. After incubation at 28°C for 6 days, the fermentation broth was transferred to sterile empty conical flasks; subsequently, sterile heavy metal mother liquor was added to achieve a cadmium concentration of 500 mg / L. After incubation at 28°C for a period of time, the supernatant was centrifuged and diluted by filtration, and the changes in heavy metal content were determined by ICP-OES.

[0042] Once the culture reaches the heavy metal removal equilibrium (the concentration of heavy metals in the fermentation broth no longer changes), the bacterial culture is centrifuged, the supernatant is discarded, the culture is freeze-dried and ground, and then the sample is placed in an X-ray diffractometer (XRD) for testing.

[0043] When Mg3(PO4)2 is used as the phosphorus source, the removal efficiency of Burkholderia neonsis HSP-21 strain of Cd from the fermentation broth is as follows:Figure 11 As shown, this indicates that the strain can achieve a timely removal effect at 0h and remains stable at 72 and 120h.

[0044] When Mg3(PO4)2 is used as the phosphorus source, the immobilization effect of Burkholderia neonsis HSP-21 strain on Cd heavy metal in fermentation broth is as follows: Figure 12 As shown, this indicates that the strain can generate Cd5(PO4)3OH and Cd5(PO4)3Cl minerals with low solubility product constants (Ksp) after reacting with Cd.

[0045] Example 8: Test on the removal capacity of Burkholderia neonetti HSP-21 for heavy metals in actual wastewater. Groundwater wastewater samples were taken from a rare earth mining area in Longnan City, Jiangxi Province, and the initial concentrations of lead (Pb) and cadmium (Cd) pollutants in the water samples were detected. The results showed that the initial concentrations of Pb and Cd were 1.66 mg / L and 0.461 mg / L, respectively.

[0046] Burkholderia neonsis HSP-21 strain was activated and cultured in LB medium until OD200. 600 The sample was inoculated into tricalcium phosphate liquid medium at a concentration of approximately 1.0 and cultured at 28°C until the logarithmic phase. Then, it was inoculated into 500 mL of the above wastewater sample at a volume ratio of 15% and cultured at 28°C for a period of time. The concentration of heavy metals in the supernatant was analyzed by inductively coupled plasma optical emission spectrometry (ICP-OES) to evaluate the heavy metal removal efficiency during the microbial remediation process.

[0047] like Figure 13 As shown, the removal rate of heavy metal Pb from wastewater samples by the new Burkholderia cepacia HSP-21 strain reached 100% after about 15 hours of incubation, and the removal rate of heavy metal Cd from wastewater samples reached 100% after about 60 hours of incubation.

[0048] As can be seen from Table 1, the treated wastewater samples can meet the groundwater standards, and the Burkholderia cepacia HSP-21 strain showed excellent heavy metal removal effect.

[0049] Table 1. Removal effect of HSP-21 on heavy metals in groundwater wastewater samples from mining areas. Heavy metal Pb Cd Original concentration (mg / L) 1.66 0.461 Final concentration (mg / L) 0.005 0.004 Groundwater standard I III Example 9: Test on the removal capacity of Burkholderia cepacia HSP-21 for heavy metals in actual wastewater Groundwater wastewater samples were taken from a rare earth mining area in Longnan City, Jiangxi Province, and the initial concentrations of lead (Pb) and cadmium (Cd) pollutants in the water samples were tested. The test results showed that the initial concentrations of Pb and Cd were 5.223 mg / L and 1.294 mg / L, respectively.

[0050] Burkholderia neonsis HSP-21 strain was activated and cultured in LB medium until OD200. 600 The sample was inoculated into tricalcium phosphate liquid medium at a concentration of approximately 1.0 and cultured at 28°C until the logarithmic phase. Then, it was inoculated into 500 mL of the above wastewater sample at a volume ratio of 15% and cultured at 28°C for a period of time. The concentration of heavy metals in the supernatant was analyzed by inductively coupled plasma optical emission spectrometry (ICP-OES) to evaluate the heavy metal removal efficiency during the microbial remediation process.

[0051] like Figure 14 As shown, the removal rate of heavy metals Pb and Cd in wastewater samples by the new Burkholderia cepacia HSP-21 strain reached 100% after about 130 hours of cultivation.

[0052] As can be seen from Table 2, the treated wastewater samples can meet the groundwater standards, and the Burkholderia cepacia HSP-21 strain showed excellent heavy metal removal effect.

[0053] Table 2. Removal effect of HSP-21 on heavy metals in groundwater wastewater samples from mining areas. Heavy metal Pb Cd Original concentration (mg / L) 5.223 1.294 Final concentration (mg / L) 0.001 0.0019 Groundwater standard I III Example 10: Test of heavy metal removal capacity of Burkholderia neonavicularis HSP-21 at different growth stages. According to the growth cycle of Burkholderia neonavicularis HSP-21 strain, Cd stock solution was added at the initial stage (0h), logarithmic phase (12h), and stationary phase (48h) to make the Cd concentration range around 1000mg / L. The strain was cultured at 28℃ and 200rpm. The concentration of heavy metal Cd in the fermentation broth was detected by inductively coupled plasma optical emission spectrometry (ICP-OES).

[0054] like Figure 15 As shown, Cd was added during the initial stage of culture of *Burkholderia cepacia* HSP-21, and the heavy metal Cd was completely removed after about 120 hours of culture; Cd was added during the logarithmic phase of culture of *Burkholderia cepacia* HSP-21, and the heavy metal Cd was completely removed after about 120 hours of culture; Cd was added during the stationary phase of culture of *Burkholderia cepacia* HSP-21, and the heavy metal Cd was completely removed after about 48 hours of culture.

[0055] Example 11: Test on the removal capacity of Burkholderia cepacia HSP-21 for heavy metals in contaminated soil. Several soil samples were taken to simulate heavy metal Cd contamination, with initial Cd concentrations of 20 mg / L, 200 mg / L, and 1000 mg / L.

[0056] Burkholderia neonsis HSP-21 strain was activated and cultured in LB medium until OD200. 600The concentration was initially set at around 1.0, then resuspended in physiological saline to 1.0, and added at 5% (volume-to-mass ratio) to the aforementioned heavy metal contaminated soil samples. The soil sample moisture content was adjusted and maintained at 20%. Samples were taken at different time points, and the bioavailable Cd content in the soil was analyzed using the BCR method to assess the excellent Cd passivation effect of this bacterium.

[0057] In summary, the novel Burkholderia cepacia HSP-21 strain of this invention originates from soil in a mining area heavily contaminated with heavy metals. It exhibits high tolerance to heavy metals and demonstrates excellent removal and passivation capabilities. Specifically, this strain not only exhibits strong phosphorus-solubilizing activity, utilizing insoluble phosphorus compounds in the environment for growth and reproduction, but also demonstrates significant removal and immobilization capabilities for heavy metals lead (Pb) and cadmium (Cd). This strain can convert lead ions into Pb₅(PO₄)₃Cl and cadmium ions into insoluble minerals such as Cd-Ca₅(PO₄)₃OH, Cd₅(PO₄)₃OH, and Cd₅(PO₄)₃Cl, promoting the stabilization of heavy metals and effectively reducing their bioavailability and environmental toxicity, thereby enhancing the long-term passivation effect of heavy metal pollution. Furthermore, this strain shows excellent removal effects on heavy metals in contaminated wastewater and soil.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A Burkholderia cenocepacia, characterized in that, The new Burkholderia cenocepacia is Burkholderia cenocepacia HSP-21, the accession number of which is CCTCC NO: M 20251344, and it was preserved in China Center for Type Culture Collection on June 12, 2025, and the address of the preservation center is Wuhan University, Wuhan, Hubei, China.

2. The cell body, fermentation broth, supernatant and / or intracellular substance of the new Burkholderia cenocepacia according to claim 1.

3. A heavy metal solidifying or removing agent, characterized by, The new Burkholderia cenocepacia according to claim 1 or the cell body, fermentation broth, supernatant and / or intracellular substance according to claim 2.

4. The heavy metal solidification or removal reagent according to claim 3, characterized in that, The heavy metal is at least one of copper, cadmium, lead, zinc, nickel, arsenic, chromium, molybdenum.

5. The heavy metal solidification or removal reagent according to claim 3, characterized in that, The concentration of the heavy metal is 0-40 g / L.

6. A phosphorus solubilizing agent of sparingly soluble phosphorus, characterized by, The new Burkholderia cenocepacia according to claim 1 or the cell body, fermentation broth, supernatant and / or intracellular substance according to claim 2.

7. The poorly soluble phosphorus solubilizing bioactive agent of claim 5, wherein, The insoluble phosphorus is at least one of magnesium phosphate, aluminum phosphate, iron phosphate, ferrous phosphate.

8. The poorly soluble phosphorus solubilizing bioactive agent of claim 5, wherein, The concentration of the insoluble phosphorus is 0-10 g / L.

9. The application of the new Burkholderia cenocepacia according to claim 1, the cell body, fermentation broth, supernatant and / or intracellular substance according to claim 2, the heavy metal solidifying agent or removal agent according to any one of claims 3-5, or the insoluble phosphorus dissolving active agent according to any one of claims 6-8 in the treatment of heavy metal pollution.

10. The application of the new Burkholderia cenocepacia according to claim 1, the cell body, fermentation broth, supernatant and / or intracellular substance according to claim 2, the heavy metal solidifying agent or removal agent according to any one of claims 3-5, or the insoluble phosphorus dissolving active agent according to any one of claims 6-8 in the remediation of heavy metals in wastewater and / or soil.

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