A strain of Kunming Stuttgart's bacteria and its application in water denitrification

Abstract

The present invention discloses a strain of Stutzerimonas kunmingensis and its application in water denitrification, relating to the field of biotechnology. The Stutzerimonas kunmingensis was deposited in the General Microbiology Center (CGMCC) of the China Culture Collection of Microorganisms on April 24, 2024, with a deposit address of No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, and a deposit number of CGMCCNO.30427. The present invention isolated and obtained Stutzerimonas kunmingensis 9‑4 from a water sample of a crucian carp recirculating aquaculture system. The strain has a good removal effect on nitrate nitrogen, nitrite nitrogen and ammonia nitrogen in the water environment. At the same time, adding hematite under light conditions can significantly improve the removal rate of nitrate nitrogen, nitrite nitrogen and ammonia nitrogen by the Stutzerimonas kunmingensis, which can be applied to the removal of nitrate nitrogen, nitrite nitrogen and ammonia nitrogen in aquaculture water environment and aquaculture tail water.

Description

Technical Field

[0001] The present invention relates to the field of biotechnology, in particular to a strain of Kunming Stuttgart's bacteria and its application in water denitrification. Background Art

[0002] China's aquaculture plays a vital role in the global supply of aquatic products, accounting for over 60% of the world's total aquaculture output. According to the "2024 China Fisheries Statistical Yearbook," China's total aquatic product output in 2023 reached 71.1617 million tons, of which 58.0961 million tons, or 81.6%, came from aquaculture. Currently, aquaculture primarily employs high-density, high-nutrient-input farming methods, which inevitably lead to significant nitrogen accumulation, which can pose a serious threat to aquatic life. Furthermore, this excessive nitrogen accumulation can enter oceans, rivers, and lakes through aquaculture tailwater discharge, causing eutrophication of receiving waters and impacting the aquatic ecosystem.

[0003] Therefore, how to efficiently treat nitrogen-containing compounds in water is an important issue that needs to be solved urgently. Summary of the Invention

[0004] The present invention aims to provide a strain of Kunming Stuttgart's bacteria and its application in water denitrification to address the aforementioned problems of the prior art. This strain has excellent removal effects on nitrate, nitrite, and ammoniacal nitrogen in aquatic environments. Furthermore, the addition of hematite under light conditions significantly increases the removal rates of nitrate, nitrite, and ammoniacal nitrogen by this strain. The strain can be applied to remove nitrate, nitrite, and ammoniacal nitrogen from aquaculture water environments and aquaculture tailwater.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a strain of Stutzerimonas kunmingensis, which was deposited in the General Microbiology Center of the China Culture Collection Administration of Microorganisms (CGMCC) on April 24, 2024, with the deposit address being No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, and the deposit number being CGMCC NO.30427.

[0007] The present invention also provides the use of the above-mentioned Kunming Stuttgart bacteria in removing nitrate nitrogen, nitrite nitrogen and / or ammonia nitrogen in a water environment.

[0008] The present invention also provides a method for removing nitrate nitrogen, nitrite nitrogen and / or ammonia nitrogen in a water environment, comprising the steps of inoculating the above-mentioned Kunming Stuttgart bacteria into the water environment and removing nitrate nitrogen, nitrite nitrogen and / or ammonia nitrogen.

[0009] The present invention also provides the use of the above-mentioned Kunming Stuttgart bacteria in the preparation of a biological preparation for removing nitrate nitrogen, nitrite nitrogen and / or ammonia nitrogen in a water environment.

[0010] The present invention also provides a biological preparation for removing nitrate nitrogen, nitrite nitrogen and / or ammonia nitrogen in a water environment, wherein the active ingredient includes the above-mentioned Kunming Stuttgart bacteria.

[0011] Furthermore, the biological agent also includes hematite.

[0012] Furthermore, the biological agent is Kunming Stuttgart / hematite composite system I;

[0013] The preparation method of the Kunming Stuttgart bacteria / hematite composite system comprises the following steps:

[0014] The Kunming Stuttgart bacteria were inoculated into the culture medium and cultured until the fermentation liquid OD 600 The pH value is 0.3, 0.05-0.3 g / 100 mL of hematite powder is added, and the culture is continued for 12 hours to obtain the Kunming Stellenomonas / hematite composite system.

[0015] Furthermore, the biological agent is Kunming Stuttgart / hematite complex system II;

[0016] The Kunming Stuttgart / hematite composite system II is prepared by cross-linking the fermentation liquid of the Kunming Stuttgart and the hematite through a sodium alginate-calcium chloride cross-linking method.

[0017] The present invention also provides the use of the above biological preparation in removing nitrate nitrogen, nitrite nitrogen and / or ammonia nitrogen in a water environment.

[0018] The present invention also provides a method for removing nitrate nitrogen, nitrite nitrogen and / or ammonia nitrogen in a water environment using the above-mentioned biological agent, comprising the steps of adding the biological agent into the water environment and removing nitrate nitrogen, nitrite nitrogen and / or ammonia nitrogen.

[0019] The present invention discloses the following technical effects:

[0020] The present invention isolated Stutzerimonas kunmingensis 9-4 from water samples in a crucian carp recirculating aquaculture system. This strain has an excellent removal effect on nitrate nitrogen, nitrite nitrogen, and ammonia nitrogen in the water environment. Furthermore, the addition of hematite under light conditions significantly increases the removal rate of nitrate nitrogen, nitrite nitrogen, and ammonia nitrogen by Stutzerimonas kunmingensis 9-4. The strain can be applied to remove nitrate nitrogen, nitrite nitrogen, and ammonia nitrogen from aquaculture water environments and aquaculture tailwater. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 This is a statistical graph showing the removal rate of nitrate nitrogen by Kunming Stuttgart's bacteria 9-4 after 8 hours of treatment under different carbon source conditions;

[0023] Figure 2 This is a statistical graph of the nitrate nitrogen removal rate after 8 hours of treatment with Kunming Stuttgart's bacteria 9-4 under different carbon-nitrogen ratios (A), treatment time (B), rotation speed (C), temperature (D), pH (E) and NaCl concentration (F);

[0024] Figure 3 This is a statistical graph of the removal rate of nitrite nitrogen by Kunming Stuttgart's bacteria 9-4 after 8 hours of treatment under different carbon-nitrogen ratios (A), treatment time (B), rotation speed (C), temperature (D), pH (E) and NaCl concentration (F);

[0025] Figure 4 This is a statistical graph of the removal rate of ammonium nitrogen after 8 hours of treatment with Kunming Stuttgart's bacteria 9-4 under different carbon-nitrogen ratios (A), treatment time (B), rotation speed (C), temperature (D), pH (E) and NaCl concentration (F);

[0026] Figure 5 Graphs showing the removal of nitrate nitrogen by the Kunming Stuttgart bacteria 9-4 / hematite composite system, the Kunming Stuttgart bacteria 9-4, and hematite under light and light-protection conditions provided by the present invention;

[0027] Figure 6 Statistical graphs showing changes in nitrite nitrogen content during the removal of nitrate nitrogen by the Kunming Stuttgart bacteria 9-4 / hematite composite system and the Kunming Stuttgart bacteria 9-4 and hematite under the conditions of illumination and light avoidance provided by the present invention;

[0028] Figure 7 Statistical graphs showing changes in ammonium nitrogen content during the removal of nitrate nitrogen by the Kunming Stuttgart bacteria 9-4 / hematite composite system and the Kunming Stuttgart bacteria 9-4 and hematite under the conditions of illumination and darkness provided by the present invention;

[0029] Figure 8 Graphs showing the removal of nitrite nitrogen by the Kunming Stuttgart bacteria 9-4 / hematite composite system, the Kunming Stuttgart bacteria 9-4, and hematite under light and light-protection conditions provided by the present invention;

[0030] Figure 9 Statistical graphs showing changes in nitrate nitrogen content during the removal of nitrite nitrogen by the Kunming Stuttgart bacteria 9-4 / hematite composite system and the Kunming Stuttgart bacteria 9-4 and hematite under the conditions of illumination and light avoidance provided by the present invention;

[0031] Figure 10 Statistical graphs showing changes in ammonium nitrogen content during the removal of nitrite nitrogen by the Kunming Stuttgart bacteria 9-4 / hematite composite system and the Kunming Stuttgart bacteria 9-4 and hematite under the conditions of illumination and light avoidance provided by the present invention;

[0032] Figure 11 Graphs showing the removal of ammonium nitrogen by the Kunming Stuttgart bacteria 9-4 / hematite composite system, the Kunming Stuttgart bacteria 9-4, and hematite under light and light-protection conditions provided by the present invention;

[0033] Figure 12 Statistical graphs showing changes in nitrate nitrogen content during the removal of ammonium nitrogen by the Kunming Stuttgart bacteria 9-4 / hematite composite system and the Kunming Stuttgart bacteria 9-4 and hematite under the conditions of illumination and darkness provided by the present invention;

[0034] Figure 13 Statistical graphs showing changes in nitrite nitrogen content during the removal of ammonium nitrogen by the Kunming Stuttgart bacteria 9-4 / hematite composite system and the Kunming Stuttgart bacteria 9-4 and hematite under the conditions of illumination and darkness provided by the present invention;

[0035] Figure 14 This is a statistical graph showing the removal rates of nitrate nitrogen, nitrite nitrogen and ammonium nitrogen by the Kunming Stuttgart bacteria 9-4 / hematite composite system and the Kunming Stuttgart bacteria 9-4 after treatment for 18 hours under the conditions of light and light avoidance provided by the present invention. DETAILED DESCRIPTION

[0036] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0037] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value within any stated value or stated range, and each smaller range between any other stated value or intermediate value within the stated range, is also encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0038] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0039] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be illustrative only.

[0040] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0041] The composition of the denitrification medium used in the following examples is (per liter): carbon source added as needed, MgSO4·7H2O 0.1 g, 1 mol / L K2HPO4 stock solution 8.96 mL, 1 mol / L KH2PO4 stock solution 1.04 mL, trace element stock solution 2 mL, KNO3, KNO2, or NH4Cl added as needed. The trace element stock solution in the culture medium is composed of the following: Na2EDTA·2H2O 0.2 g / L, CaCl2 0.2 g / L, MnCl2·7H2O 0.8 g / L, CoCl2·6H2O 0.35 g / L, ZnSO4 0.4 g / L, CuSO4 0.4 g / L, FeSO4 1 g / L, (NH4)6Mo7O 24 4H2O 0.65g / L.

[0042] Example 1 Strain Isolation, Screening, Identification and Preservation

[0043] 1. Separation and screening

[0044] Water samples from a crucian carp recirculating aquaculture system were inoculated into enrichment medium for expansion and culture at 28°C for 48 hours. Subsequently, the samples were serially diluted with sterile saline and plated onto BTB plates for initial screening. Bacteria that appeared blue around the colonies were isolated and purified. The isolated bacteria were then inoculated into LB liquid medium containing sodium nitrate in a Büchner tube for secondary screening and incubated at 16°C for 7 days. Bacteria that appeared bubbles in the Büchner tube were inoculated into denitrification medium containing sodium nitrate and cultured at 28°C for 24 hours. The fermentation broth was centrifuged at 12,000 rpm for 1 minute, and the supernatant was assayed for nitrate nitrogen content. Uninoculated denitrification medium containing sodium nitrate was used as a control. The target strains were selected for those with significantly lower nitrate nitrogen content compared to the control. After primary and secondary screening, a single bacterial strain, 9-4, capable of removing nitrate nitrogen, was identified from the target strains.

[0045] 2. Identification

[0046] Strain 9-4 has the following physiological and biochemical characteristics:

[0047] (1) Strain 9-4 is a Gram-negative bacterium;

[0048] (2) The colonies of strain 9-4 were pale yellow, moist, translucent, with irregular edges and a smooth surface;

[0049] (3) Strain 9-4 can be cultured in LB medium.

[0050] (4) Other physiological and biochemical characteristics of strain 9-4 are shown in Table 1.

[0051] Table 1 Physiological and biochemical characteristics of Kunming Stuttgart's 9-4 strain

[0052]

[0053] Note: “+”: positive; “-”: negative.

[0054] The nucleotide sequence of the 16S rDNA region obtained by PCR amplification of strain 9-4 using universal primers 27F and 1492R is shown in SEQ ID NO.1.

[0055] SEQ ID NO.1:

[0056]

[0057] Identification revealed that strain 9-4 belonged to Stutzerimonas kunmingensis.

[0058] 3. Biological Deposit

[0059] Stutzerimonas kunmingensis 9-4 was deposited in the General Microbiology Center of China Culture Collection Administration (CGMCC) on April 24, 2024. The deposit address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, and the deposit number is CGMCC NO.30427.

[0060] Example 2 Carbon source selection for the denitrification process of Kunming Stuttgart's 9-4

[0061] Kunming Stuttgart bacteria 9-4 were inoculated into LB medium and cultured at 28°C until OD 600 The nitrate removal efficiency was 0.8. The cells were collected by centrifuging 10 mL of fermentation broth at 12,000 rpm for 1 minute and washed three times with sterile saline. The cells were inoculated into denitrification medium containing different carbon sources and 1 mmol / L sodium nitrate to test the effects of sodium citrate, sucrose, glucose, soluble starch, and sodium succinate as carbon sources on nitrate removal.

[0062] The experimental results are shown in Figure 1 .

[0063] Result analysis: Sodium citrate and sodium succinate were the optimal carbon sources for the denitrification process of Kunming Stuttgart's 9-4. Sodium citrate was used as the carbon source in the subsequent examples.

[0064] Example 3: Removal of nitrate nitrogen from denitrification medium by Kunming Stuttgart's bacteria 9-4

[0065] Kunming Stuttgart bacteria 9-4 were inoculated into LB medium and cultured at 28°C until OD 600 The nitrate removal efficiency was tested by centrifuging 10 mL of fermentation broth at 12,000 rpm for 1 minute to collect the cells, which were then washed three times with sterile saline. The cells were then inoculated into a denitrification medium containing 1 mmol / L sodium nitrate and incubated for 8 hours. The effects of different carbon-nitrogen ratios (mass ratios), treatment time, rotation speed, temperature, pH, and salinity on nitrate removal were examined.

[0066] The experimental results are shown in Figure 2 .

[0067] Results: Kunming Stuttgart's 9-4 strain achieved a nitrate removal efficiency exceeding 50% when the C / N ratio was 10-25, the treatment time was greater than 5 hours, the rotation speed was 50-150 rpm, the temperature was 16-34°C, the pH was 7.5-9, and the NaCl concentration was 0-10 g / L. The optimal C / N ratio was 15, the rotation speed was 50-100, the temperature was 22-34°C, the pH was 7.5, and the NaCl concentration was 0 mg / L. After 7 hours of treatment, the nitrate removal efficiency reached over 95%. After 8 hours of treatment under these optimal conditions, the strain achieved 100% nitrate removal, with no accumulation of nitrite or ammonium.

[0068] Example 4: Removal of Nitrite Nitrogen from Denitrification Medium by Kunming Stuttgart's Bacteria 9-4

[0069] Kunming Stuttgart bacteria 9-4 were inoculated into LB medium and cultured at 28°C until OD 600 The nitrite removal efficiency was 0.8. The cells were collected by centrifuging 10 mL of fermentation broth at 12,000 rpm for 1 minute and washed three times with sterile saline. The cells were inoculated into a denitrification medium containing 1 mmol / L sodium nitrite and cultured for 8 hours. The effects of different carbon-nitrogen ratios, treatment time, rotation speed, temperature, pH, and salinity on nitrite removal were examined.

[0070] The experimental results are shown in Figure 3 .

[0071] Results: Kunming Stuttgart's 9-4 strain achieved a nitrite-nitrogen removal efficiency exceeding 50% when the C / N ratio was 10-25, the treatment time was greater than 4 hours, the rotation speed was 50-150 rpm, the temperature was 16-34°C, the pH was 6.5-9, and the NaCl concentration was 0-10 g / L. The optimal C / N ratio was 20-25, the optimal rotation speed was 50-100, the optimal temperature was 22-34°C, the optimal pH was 7.5-8, and the optimal NaCl concentration was 0 mg / L. After 7 hours of treatment, the nitrite-nitrogen removal efficiency reached over 95%. After 8 hours of treatment under these optimal conditions, Kunming Stuttgart's 9-4 strain achieved a 100% nitrite-nitrogen removal efficiency, with no accumulation of nitrate and ammonium nitrogen.

[0072] Example 5: Removal of ammonium nitrogen from denitrification medium by Kunming Stuttgart's bacteria 9-4

[0073] Kunming Stuttgart bacteria 9-4 were inoculated into LB medium and cultured at 28°C until OD 600The cell culture was collected by centrifuging 10 mL of fermentation broth at 12,000 rpm for 1 minute and then washed three times with sterile saline. The cells were inoculated into a denitrification medium containing 1 mmol / L ammonium chloride and cultured for 8 hours. The effects of different carbon-nitrogen ratios, treatment time, rotation speed, temperature, pH, and salinity on the removal of ammonium nitrogen were examined.

[0074] The experimental results are shown in Figure 4 .

[0075] Results: Kunming Stuttgart 9-4 achieved an ammonium nitrogen removal efficiency exceeding 85% when the carbon-nitrogen ratio was 10-25, the treatment time was greater than 4 hours, the rotation speed was 50-150 rpm, the temperature was 16-34°C, the pH was 6.5-9, and the NaCl concentration was 0-10 g / L. The optimal carbon-nitrogen ratio was 15-25, the optimal rotation speed was 50-150, the optimal temperature was 22-34°C, the optimal pH was 6.5-7.5, and the optimal NaCl concentration was 0 mg / L. After 7 hours of treatment, the ammonium nitrogen removal efficiency reached over 95%. After 6 hours of treatment under these optimal conditions, Kunming Stuttgart 9-4 achieved a 100% ammonium nitrogen removal efficiency, with no accumulation of nitrate or nitrite nitrogen.

[0076] Example 6: Removal of nitrate, nitrite, and ammonium nitrogen from denitrification medium using a Kunming Stuttgart's 9-4 / hematite composite system

[0077] Kunming Stuttgart bacteria 9-4 were inoculated into LB medium and cultured at 28°C until OD 600 The pH value was 0.3, 0.2 g / 100 mL of hematite powder was added (the amount of hematite powder added can be 0.05-0.3 g / 100 mL), and the culture was continued for 12 h to prepare the Kunming Stuttgart bacteria 9-4 / hematite composite system.

[0078] Kunming Stuttgart bacteria 9-4, Kunming Stuttgart bacteria 9-4 / hematite composite system, and hematite were inoculated into denitrification medium containing sodium nitrate, sodium nitrite, or ammonium chloride, respectively. The culture was carried out under light conditions for several hours, and the concentration changes of nitrate nitrogen, nitrite nitrogen, and ammonium nitrogen in the culture medium were detected.

[0079] The experimental results are shown in Figure 5-Figure 13 .

[0080] Results: The removal rates of nitrate, nitrite, and ammonium nitrogen by the Kunming Stuttgart-9-4 / hematite complex under light conditions (9-4 / hematite-light) were significantly higher than those by the Kunming Stuttgart-9-4 / hematite complex under dark conditions (9-4 / hematite-dark) and by Stuttgart-9-4 (9-4-light, 9-4-dark). Furthermore, the addition of hematite alone had no effect on the removal of nitrate, nitrite, and ammonium. During the nitrate removal process, no accumulation of nitrite and ammonium nitrogen occurred at the endpoint of the treatments with the Kunming Stuttgart-9-4 / hematite complex and Stuttgart-9-4 under both light and dark conditions. During the removal of nitrite nitrogen, no accumulation of nitrate nitrogen and ammonium nitrogen was observed at the end of treatment with the Kunming Stuttgart-Baumans 9-4 / hematite composite system and the Kunming Stuttgart-Baumans 9-4 under both light and dark conditions. During the removal of ammonia nitrogen, no accumulation of nitrate nitrogen and nitrite nitrogen was observed at the end of treatment with the Kunming Stuttgart-Baumans 9-4 / hematite composite system and the Kunming Stuttgart-Baumans 9-4 under both light and dark conditions.

[0081] Example 7: Removal of nitrate, nitrite and ammonium nitrogen from denitrification medium by the Kunming Stuttgart's 9-4-hematite composite system

[0082] Kunming Stuttgart bacteria 9-4 were inoculated into LB medium and cultured at 28°C until OD 600 0.8. Take 100mL of the fermentation broth of Kunming Stuttgart 9-4 after culture, centrifuge to remove the supernatant and wash twice with sterile ultrapure water. The bacteria and 0.1g of hematite powder were mixed evenly in 10mL of 2% sterile sodium alginate solution. The mixture was added dropwise to a 2% CaCl2 solution via a syringe and then placed at 4°C for 2h to prepare the Kunming Stuttgart 9-4 / hematite composite system. Kunming Stuttgart 9-4, the Kunming Stuttgart 9-4 / hematite composite system, and hematite were inoculated into denitrified culture medium containing sodium nitrate, sodium nitrite, or ammonium chloride, respectively, and cultured under light conditions for 18h. The changes in the concentrations of nitrate nitrogen, nitrite nitrogen, and ammonium nitrogen in the culture medium were detected.

[0083] The experimental results are shown in Figure 14 .

[0084] Analysis of results: The removal rates of nitrate nitrogen, nitrite nitrogen and ammonium nitrogen by the Kunming Stuttgart bacteria 9-4 / hematite composite system under light conditions were significantly higher than those of the Kunming Stuttgart bacteria 9-4 / hematite composite system under dark conditions (9-4 / hematite-darkness) and Kunming Stuttgart bacteria 9-4 (9-4-light, 9-4-darkness).

[0085] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A strain of Stutzerimonas kunmingensis, characterized in that: The Kunming Sterlingella was deposited in the General Microbiology Center of the China Culture Collection Administration (CGMCC) on April 24, 2024. The deposit address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, and the deposit number is CGMCC NO. 30427.

2. Use of the Kunming Stuttgart bacteria according to claim 1 in removing nitrate nitrogen, nitrite nitrogen and / or ammonia nitrogen in a water environment.

3. A method for removing nitrate nitrogen, nitrite nitrogen and / or ammonia nitrogen in an aqueous environment, characterized in that: The method comprises the steps of inoculating the Kunming Stuttgart bacteria according to claim 1 into a water environment and removing nitrate nitrogen, nitrite nitrogen and / or ammonia nitrogen.

4. Use of the Kunming Stuttgart bacteria according to claim 1 in preparing a biological agent for removing nitrate nitrogen, nitrite nitrogen and / or ammonia nitrogen in an aquatic environment.

5. A biological agent for removing nitrate nitrogen, nitrite nitrogen and / or ammonia nitrogen in an aquatic environment, characterized in that: The active ingredient comprises the Kunming Stuttgart bacteria according to claim 1.

6. The biological preparation according to claim 5, characterized in that The biological agent also includes hematite.

7. The biological preparation according to claim 6, characterized in that The biological agent is a Kunming Stuttgart bacteria / hematite composite system ; The Kunming Stuttgart bacteria / hematite composite system The preparation method comprises the following steps: The Kunming Stuttgart bacteria were inoculated into the culture medium and cultured until the fermentation liquid OD 600 The concentration of hematite powder was 0.3, 0.05-0.3 g / 100 mL was added, and the culture was continued for 12 h to obtain the Kunming Sterlingella / hematite composite system. .

8. The biological preparation according to claim 6, characterized in that The biological agent is a Kunming Stuttgart bacteria / hematite composite system ; The Kunming Stuttgart bacteria / hematite composite system The invention is prepared by cross-linking the fermentation liquid of Kunming Stuttgart's bacteria and the hematite through a sodium alginate-calcium chloride cross-linking method.

9. Use of the biological agent according to any one of claims 5 to 8 for removing nitrate nitrogen, nitrite nitrogen and / or ammonia nitrogen in an aqueous environment.

10. A method for removing nitrate nitrogen, nitrite nitrogen and / or ammonia nitrogen in an aqueous environment using the biological agent according to any one of claims 5 to 8, characterized in that: The method comprises the steps of adding the biological agent into a water environment to remove nitrate nitrogen, nitrite nitrogen and / or ammonia nitrogen.

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