Pseudomonas aeruginosa and application thereof in denitrification of river sewage

Abstract

The invention belongs to the field of microbiology, and relates to pseudomonas aeruginosa, which is named as Pseudomonas aeruginosa in taxonomy, and has a preservation number of CCTCC M 2026385. The invention also provides a river sewage treatment method. According to the method, the pseudomonas aeruginosa is added into a river for denitrification. The pseudomonas aeruginosa provided by the invention has denitrification performance under the condition of low carbon nitrogen ratio, and has relatively high denitrification capacity under the environment of 20-30 DEG C and the carbon nitrogen ratio of 4-20, so that the pseudomonas aeruginosa provided by the invention can be used for improving the water quality in river water with low carbon nitrogen ratio.

Description

Technical Field

[0001] This invention belongs to the field of microbiology and relates to a strain and its application, specifically a strain of Pseudomonas aeruginosa and its application. Background Technology

[0002] Rivers, as important collection areas for urban surface runoff and pollutants, are susceptible to various pollution sources, including domestic sewage, industrial wastewater, and effluent from wastewater treatment plants. This has led to increasingly prominent water pollution problems, seriously threatening the aquatic ecological environment and the safety of residents' lives and production. Therefore, carrying out river pollution control is of great significance for improving river water quality, restoring aquatic ecological functions, and enhancing the quality of the urban ecological environment.

[0003] Polluted urban rivers are typically characterized by high ammonia nitrogen concentrations and low carbon-to-nitrogen ratios (C / N). Ammonia nitrogen is a key indicator of river pollution; its excessive accumulation not only causes blackening and odor of the water and eutrophication but also severely impacts the survival of aquatic organisms and the stability of the aquatic ecosystem. Therefore, reducing ammonia nitrogen levels in river water has become a crucial research direction in current river management.

[0004] Currently, biological denitrification technology is widely used in China for ammonia nitrogen treatment in river wastewater. This involves adding microbial strains with denitrification capabilities to the water body to achieve the biological transformation and removal of ammonia nitrogen. However, under the low carbon-to-nitrogen ratio conditions commonly found in urban river water bodies, the growth activity and denitrification efficiency of microbial strains are often significantly limited, thus affecting the actual treatment effect. Therefore, screening for functional microbial strains that can still maintain high denitrification capacity under low carbon-to-nitrogen ratio and low-temperature conditions is of great significance for improving the efficiency of biological denitrification in river water bodies and promoting the ecological restoration of urban rivers.

[0005] Currently, ammonia nitrogen treatment in river wastewater remains inefficient even under conditions of low carbon-to-nitrogen ratios. Summary of the Invention

[0006] To address the aforementioned technical problems in the prior art, this invention provides a method using Pseudomonas aeruginosa and its applications, which aims to solve the problem of low efficiency in the treatment of ammonia nitrogen in river sewage in the prior art.

[0007] This invention provides a strain of Pseudomonas aeruginosa, taxonomically named Pseudomonas aeruginosa Its accession number is CCTCC M 2026385.

[0008] The present invention also provides a microbial preparation containing the above-mentioned Pseudomonas aeruginosa.

[0009] Furthermore, the content of *Pseudomonas aeruginosa* in the microbial preparation is greater than or equal to 1 × 10⁻⁶. 6 CFU / mL or 1×10 6 CFU / g.

[0010] The present invention also provides a composition containing the above-mentioned Pseudomonas aeruginosa or the above-mentioned microbial preparation.

[0011] The present invention also provides a river sewage treatment agent, wherein the river sewage treatment agent contains the above-mentioned Pseudomonas aeruginosa, the above-mentioned microbial preparation, or the above-mentioned combination.

[0012] The present invention also provides the application of the above-mentioned Pseudomonas aeruginosa, the above-mentioned microbial preparation, the above-mentioned composition, or the above-mentioned river sewage treatment agent in improving river water quality.

[0013] Furthermore, the river water contains water with a dissolved oxygen concentration of less than 1 mg / L.

[0014] Furthermore, the improvement of river water quality includes at least one of the following effects: (1) Reduce the chemical oxygen demand (COD) of river water; (2) Reduce the ammonia nitrogen content in river water (NH4) + -N); (3) Reduce the total nitrogen (TN) in the river water.

[0015] The present invention also provides a method for treating river sewage, wherein the method comprises adding the above-mentioned Pseudomonas aeruginosa, the above-mentioned microbial preparation, the above-mentioned composition, or the above-mentioned river sewage treatment agent into the river for denitrification.

[0016] In one implementation, the application is to culture to OD 600 Inoculate the river sewage with a bacterial solution of 0.5~1.5.

[0017] In one embodiment, the bacterial solution is inoculated into river sewage and reacted for at least 24 hours.

[0018] In one embodiment, the inoculation amount of the bacterial solution is 0.1-10%.

[0019] In one implementation, the application includes water quality improvement.

[0020] In one embodiment, the wastewater includes river sewage, aquaculture wastewater, and livestock farming wastewater.

[0021] The *Pseudomonas aeruginosa* JSUTYLT001 provided by this invention exhibits denitrification capabilities under low carbon-to-nitrogen ratio conditions. Specifically, the *Pseudomonas aeruginosa* JSUTYLT001 provided by this invention demonstrates high denitrification capacity at 20-30 °C and a carbon-to-nitrogen ratio of 4-20. Therefore, the *Pseudomonas aeruginosa* JSUTYLT001 provided by this invention can improve water quality in river water with a low carbon-to-nitrogen ratio.

[0022] Compared with existing technologies, the technical effects of this invention are positive and significant. This invention isolates a strain of *Pseudomonas aeruginosa* from sediments in Changzhou river channels. This *Pseudomonas aeruginosa* possesses denitrification capabilities, exhibiting a high ammonia nitrogen removal rate in river water under a carbon-to-nitrogen ratio of 4. The *Pseudomonas aeruginosa* provided by this invention maintains high denitrification capacity at temperatures ranging from 20-40 °C and carbon-to-nitrogen ratios between 4 and 20. Attached Figure Description

[0023] Figure 1 The image shows a growth plate diagram of Pseudomonas aeruginosa.

[0024] Figure 2 An evolutionary relationship diagram of Pseudomonas aeruginosa is shown. Detailed Implementation

[0025] EM medium: ammonium sulfate 0.5 g / L, potassium nitrate 0.36 g / L, sodium citrate 4.0 g / L, dipotassium hydrogen phosphate·3H₂O 6.5 g / L, magnesium sulfate·7H₂O 2.5 g / L, sodium chloride 2.5 g / L, ferrous sulfate·7H₂O 0.05 g / L, manganese sulfate 0.04 g / L. All components were dissolved in distilled water, the pH was adjusted to 7.0, and the medium was autoclaved at 121 °C for 20 min, then cooled for later use.

[0026] DM medium: Potassium nitrate 0.36 g / L, disodium hydrogen phosphate·12H2O 10.55 g / L, potassium dihydrogen phosphate 1.5 g / L, magnesium sulfate·7H2O 0.1 g / L, sodium citrate 4.0 g / L. Additionally, 0.2% (v / v) of trace element stock solution was added. The trace element stock solution consisted of: EDTA-Na25 0.0 g / L, zinc sulfate 2.2 g / L, calcium chloride 5.5 g / L, manganese chloride·4H2O 5.06 g / L, ferrous sulfate·7H2O 5.0 g / L, copper sulfate·5H2O 1.57 g / L, cobalt chloride·6H2O 1.61 g / L. All components were dissolved in distilled water, the pH was adjusted to 7.0, and the solution was autoclaved at 121 °C for 20 min before use.

[0027] GN solid medium: potassium nitrate 1.0 g / L, sodium citrate 8.5 g / L, L-asparagine 1.0 g / L, potassium dihydrogen phosphate 1.0 g / L, magnesium sulfate·7H2O 1.0 g / L, calcium chloride·6H2O 0.2 g / L, ferric chloride·6H2O 0.05 g / L. Add bromothymol blue (BTB) indicator solution to the medium to a final concentration of 0.1% (v / v). To prepare GN solid medium, add 2% (w / v) agar powder to the above liquid medium, autoclave at 121 °C for 20 min, cool to approximately 50 °C, and pour into plates for later use.

[0028] LY liquid culture medium: sodium citrate 1.0 g / L, ammonium sulfate 1.0 g / L; dipotassium hydrogen phosphate 1.0 g / L, magnesium sulfate heptahydrate 1.0 g / L, calcium chloride hexahydrate 0.2 g / L, ferrous chloride 0.05 g / L. All components were dissolved in distilled water and autoclaved at 121 °C for 20 min, then cooled for later use.

[0029] Example 1: Screening and Identification of Strains (1) Sample collection Take 2 g of sediment samples from the Changzhou river channel, inoculate them into a sterile container containing 1000 mL of liquid enrichment medium (EM), mix well, and use them as the initial samples for strain screening.

[0030] (2) Enrichment culture The inoculation system obtained in step (1) was placed in a shaker and enriched at 25 ℃ and 150 rpm. A semi-continuous culture method was adopted during the enrichment culture process. Every 48 h, 50 mL of old culture medium was aseptically extracted and 50 mL of fresh sterile liquid enrichment medium (EM) was added. The culture was carried out continuously for 20 days to gradually enrich the target bacterial population that has a growth advantage under the culture conditions and obtain the enriched bacterial solution.

[0031] (3) Screening and cultivation Take the enriched bacterial solution obtained in step (2) and inoculate it into liquid selection medium (DM). Perform selection culture at 25 ℃ and 150 rpm. During the selection culture process, a semi-continuous culture method is also adopted. Every 24 h, 50 mL of old medium is aseptically extracted and 50 mL of fresh sterilized liquid selection medium (DM) is added at the same time. The selection culture is continued until the growth of the bacterial community in the culture system tends to be stable, thereby obtaining the selected dominant bacterial solution.

[0032] (4) Coating separation Take the bacterial suspension obtained in step (3), perform serial dilutions, and then take 100 μL of the bacterial suspension at an appropriate dilution and spread it evenly on the surface of a GN solid medium plate. Invert the spread GN solid medium plate in a 25 ℃ incubator for 48 h. After the incubation, observe the morphological characteristics of the colonies on the plate, and pick single colonies with different morphologies or typical characteristics for streak purification.

[0033] (5) Purification culture The single colonies selected in step (5) were inoculated onto new GN solid medium plates and purified by streak plating. The culture was carried out at 25 °C for 48 h. The streak purification was repeated 3 to 5 times until a single pure strain with consistent colony morphology and no contamination was obtained.

[0034] (7) Expand cultivation Single colonies were picked from the purified plates and inoculated into liquid culture medium, and cultured at 25 °C and 150 rpm for 48 h. When the OD of the bacterial culture... 600 When the value reaches 0.8, stop the culture and obtain the experimental bacterial solution (strain P1).

[0035] 2. Strain identification: The strain was identified by 16S rDNA as Pseudomonas aeruginosa.

[0036] The phylogenetic tree constructed based on the 16S rRNA gene sequence showed that strain P1 is related to multiple strains... Pseudomonas aeruginosa The reference strains clustered within the same phylogenetic branch, indicating that the strain belongs to *Pseudomonas aeruginosa*. Meanwhile, strain P1 forms a relatively independent branch, differing from existing publicly available strains in its phylogenetic position, indicating that it possesses genetic characteristics distinct from existing strains and can be considered a novel functional strain (strain P1) provided by this invention.

[0037] This invention preserves the above-mentioned strain *Pseudomonas aeruginosa* JSUTYLT001 as biological material and names it taxonomically. Pseudomonas aeruginosa It was deposited on March 9, 2026 at the China Center for Type Culture Collection, with accession number CCTCC M 2026385, located at Luojia Mountain, Bayi Road, Wuchang District, Wuhan City, Hubei Province.

[0038] Example 2: Denitrification capacity of strains under different carbon-to-nitrogen ratios (1) The *Pseudomonas aeruginosa* strain JSUTYLT001 obtained in Example 1 was inoculated into 100 mL of LY liquid medium at a volume ratio of 1%, and cultured at 25 °C and pH 7.0. LY liquid medium with C / N ratios of 4:1, 7:1, 10:1, 15:1 and 20:1 was also prepared.

[0039] (2) After each group of reaction systems was cultured for 240 h, the OD of the bacterial culture was measured. 600 Value, ammonia nitrogen removal rate and COD removal rate.

[0040] (3) As shown in Table 1, different C / N ratios have a significant impact on the denitrification and carbon removal performance of the strains. In this experiment, the initial ammonia nitrogen concentration of each reaction system was 200 mg / L. Different C / N ratios were set by adjusting the carbon source dosage, corresponding to initial COD concentrations of 800 mg / L, 1400 mg / L, 2000 mg / L, 3000 mg / L, and 4000 mg / L, respectively. Under different C / N conditions, the strains all showed certain denitrification and carbon removal capabilities. Among them, the strains exhibited the best growth state and final OD when the C / N ratio was 15:1. 600 The C / N ratio was 0.9711, with an ammonia nitrogen removal rate of 82.14% and a COD removal rate of 65.1%. At a C / N ratio of 10:1, the ammonia nitrogen removal rate was 81.44% and the COD removal rate was 65.2%, also demonstrating good denitrification and decarbonization effects. Even at a C / N ratio of 4:1, the ammonia nitrogen removal rate still reached 55.19%, indicating that this strain still possesses a certain denitrification capacity under low carbon source conditions. Overall, this strain exhibits superior comprehensive denitrification and decarbonization performance at C / N ratios ranging from 10:1 to 15:1.

[0041] Table 1. Denitrification capacity of strains under different carbon-to-nitrogen ratios

[0043] Example 3: Denitrification and carbon removal capabilities of strains under different temperature conditions (1) The *Pseudomonas aeruginosa* strain JSUTYLT001 obtained in Example 1 was inoculated into 100 mL of LY liquid medium at a volume ratio of 1%. Under the condition that the shaking speed is 150 rpm / min, the culture temperature was set to 20 ℃, 25 ℃, 30 ℃, 35 ℃ and 40 ℃ respectively for culture.

[0044] (2) After 240 hours of incubation, the OD of the bacterial culture in each group of reaction systems was measured. 600 The values ​​of ammonia nitrogen degradation rate and COD degradation rate were used to evaluate the effects of different temperature conditions on the growth and denitrification and carbon removal capabilities of the strain.

[0045] (3) As can be seen from Table 2, different temperatures have a significant impact on the growth and denitrification / carbon removal performance of the strain. In this experiment, the initial ammonia nitrogen concentration of the reaction system was 2100 mg / L, and the initial COD concentration was 8650 mg / L. Under the condition of 150 rpm / min remaining constant, the strain showed a certain degradation ability for ammonia nitrogen and COD under different temperature conditions. Among them, at 20 ℃, after 240 h, the ammonia nitrogen concentration decreased to 1152 mg / L, with an ammonia nitrogen degradation rate of 45.14%, and the COD concentration decreased to 4185 mg / L, with a COD degradation rate of 51.62%, and the final OD 600 The value was 0.42; at 25 ℃, after 240 h, the ammonia nitrogen concentration decreased to 722 mg / L, with an ammonia nitrogen degradation rate of 65.62%, and the COD concentration decreased to 2011 mg / L, with a COD degradation rate of 76.75%, and the final OD... 600 The value was 0.85; at 30 ℃, after 240 h, the ammonia nitrogen concentration decreased to 527 mg / L, with an ammonia nitrogen degradation rate of 74.90%, and the COD concentration decreased to 605 mg / L, with a COD degradation rate of 93.01%, and the final OD... 600 The value was 1.62; at 35 ℃, after 240 h, the ammonia nitrogen concentration decreased to 681 mg / L, with an ammonia nitrogen degradation rate of 67.57%, and the COD concentration decreased to 1852 mg / L, with a COD degradation rate of 78.59%, and the final OD... 600 The value was 0.91; at 40 ℃, after 240 h, the ammonia nitrogen concentration decreased to 1248 mg / L, with an ammonia nitrogen degradation rate of 40.57%, and the COD concentration decreased to 5121 mg / L, with a COD degradation rate of 40.80%, and the final OD... 600 The value is 0.38.

[0046] The results showed that the strain exhibited the best denitrification and carbon removal capabilities and growth status at 30 ℃, and had good denitrification and carbon removal capabilities in the range of 25–35 ℃.

[0047] Table 2. Degradation of ammonia nitrogen and COD at different temperatures under constant 150 rpm / min conditions.

[0048] Example 4: Denitrification and carbon removal capabilities of strains under different rotation speeds (1) The Pseudomonas aeruginosa JSUTYLT001 obtained in Example 1 was inoculated into 100 mL of LY liquid culture medium at a volume ratio of 1%. Under the condition of 30 °C, the shaking speed was set to 110 rpm / min, 130 rpm / min, 150 rpm / min, 170 rpm / min and 210 rpm / min respectively for culture.

[0049] (2) After 240 h of incubation, the OD of the bacterial culture in each group of reaction systems was measured. 600 The values ​​of nitrogen, ammonia nitrogen degradation rate, and COD degradation rate were used to evaluate the effects of different rotation speeds on the growth and denitrification and carbon removal capabilities of the strain.

[0050] (3) As can be seen from Table 3, different shaking speeds have a significant impact on the growth and denitrification and decarbonization performance of the strain. In this experiment, the initial ammonia nitrogen concentration of the reaction system was 2100 mg / L, the initial COD concentration was 8650 mg / L, and the culture temperature was maintained at 30 ℃. The effect of different dissolved oxygen conditions on the denitrification and decarbonization ability of the strain was investigated by adjusting the shaking speed.

[0051] Experimental results showed that, under conditions of 110 rpm / min and culturing for 240 h, the ammonia nitrogen concentration decreased from 2100 mg / L to 986 mg / L, with an ammonia nitrogen degradation rate of 53.05%; the COD concentration decreased from 8650 mg / L to 3511 mg / L, with a COD degradation rate of 59.41%, and the final OD... 600 The value was 0.55. When the rotation speed was increased to 130 rpm / min, after 240 h, the ammonia nitrogen concentration decreased to 754 mg / L, with an ammonia nitrogen degradation rate of 64.10%; the COD concentration decreased to 2121 mg / L, with a COD degradation rate of 75.48%, and the final OD... 600 The value was 0.82. At a rotation speed of 150 rpm / min, after 240 h, the ammonia nitrogen concentration decreased to 526 mg / L, with an ammonia nitrogen degradation rate of 74.95%; the COD concentration decreased to 1102 mg / L, with a COD degradation rate of 87.26%, and the final OD... 600 The value was 1.73. When the rotation speed was further increased to 170 rpm / min, after 240 h, the ammonia nitrogen concentration was 575 mg / L, and the ammonia nitrogen degradation rate was 72.62%; the COD concentration was 1421 mg / L, and the COD degradation rate was 83.57%, with the final OD... 600The value was 1.12. At a rotation speed of 210 rpm / min, after 240 h, the ammonia nitrogen concentration was 653 mg / L, with an ammonia nitrogen degradation rate of 68.90%; the COD concentration was 2540 mg / L, with a COD degradation rate of 70.64%, and the final OD... 600 The value is 0.95.

[0052] Comprehensive analysis showed that as the rotation speed increased from 110 rpm / min to 150 rpm / min, the growth rate of the strain and its ability to degrade ammonia nitrogen and COD both increased. However, when the rotation speed was further increased to 170 rpm / min and 210 rpm / min, the growth rate and pollutant removal capacity of the strain decreased. This indicates that 150 rpm / min is the most suitable rotation speed for this strain under the experimental conditions.

[0053] Table 3. Degradation rates of ammonia nitrogen and COD at different rotation speeds under constant temperature (30℃).

[0054] Example 5: Denitrification and carbon removal capabilities of strains under different culture time conditions (1) The *Pseudomonas aeruginosa* strain JSUTYLT001 obtained in Example 1 was inoculated into LY liquid medium at a volume ratio of 1%, and cultured under suitable culture conditions. Samples were taken at 24 h, 48 h, 96 h, 144 h and 192 h for testing.

[0055] (2) The removal rates of COD, ammonia nitrogen and total nitrogen (TN) in the reaction system were measured at different culture times to evaluate the denitrification and carbon removal performance of the strain under different culture time conditions.

[0056] (3) As shown in Table 4, different culture times have a significant impact on the nitrogen and carbon removal performance of the strain. In this experiment, an artificially prepared reaction system was used. The initial ammonia nitrogen concentration in each group was 200 mg / L, and the initial COD concentration was 2000 mg / L. Under the same culture conditions, with the extension of culture time, the strain showed a gradually increasing removal capacity for COD, ammonia nitrogen, and TN. When cultured for 24 h, the COD concentration decreased from 2000 mg / L to 705 mg / L, with a COD removal rate of 64.74%; the ammonia nitrogen concentration decreased from 200 mg / L to 140 mg / L, with an ammonia nitrogen removal rate of 29.98%; and the TN concentration decreased from 200 mg / L to 140 mg / L, with a TN removal rate of 29.98%. After 48 h of incubation, the COD concentration further decreased to 266 mg / L, with a COD removal rate of 86.70%; the ammonia nitrogen concentration decreased to 65.5 mg / L, with an ammonia nitrogen removal rate of 67.24%; and the TN concentration decreased to 65.5 mg / L, with a TN removal rate of 67.24%. After 96 h of incubation, the COD concentration was 254 mg / L, with a COD removal rate of 87.28%; the ammonia nitrogen concentration was 64.3 mg / L, with an ammonia nitrogen removal rate of 67.83%; and the TN removal rate was 67.83%. After 144 h of incubation, the COD concentration decreased to 220 mg / L, with a COD removal rate of 89.01%; the ammonia nitrogen concentration was 61.5 mg / L, with an ammonia nitrogen removal rate of 69.23%; and the TN removal rate was 69.23%. After 192 h of cultivation, the COD concentration decreased to 139 mg / L, with a COD removal rate of 93.06%; the ammonia nitrogen concentration decreased to 53.8 mg / L, with an ammonia nitrogen removal rate of 73.08%; and the TN removal rate also reached 73.08%.

[0057] Comprehensive analysis shows that the removal rates of COD, ammonia nitrogen, and TN by the strain gradually increased with the extension of cultivation time, indicating that the strain has relatively stable metabolic activity and strong pollutant degradation ability during continuous cultivation. The results indicate that under the experimental conditions, the strain exhibited the best comprehensive nitrogen and carbon removal effect when the cultivation time reached 192 h, providing important time parameters for its application in urban river water body restoration.

[0058] Table 4. Denitrification and carbon removal capabilities of strains under different rotation speeds.

[0059] Example 6: Application of Pseudomonas aeruginosa JSUTYLT001 in actual river wastewater denitrification (1) Take strain P1 obtained in Example 1 and inoculate it into 100 mL of actual sewage collected from Changzhou River (COD concentration 40 mg / L, ammonia nitrogen concentration 8 mg / L) at a volume ratio of 1%. Cultivate it at room temperature (about 18 ℃) and aeration (ensuring dissolved oxygen is above 6 mg / L). Set cultivation time to 0 h, 2 h, 5 h, 7 h and 17 h, and take samples at different cultivation time points to determine ammonia nitrogen concentration.

[0060] (2) After sampling at each time point, the samples were tested according to the ammonia nitrogen determination method. At the same time, a blank group, a dry bacteria group (strain P1), and a mixed bacteria group (a 1:1 mixture of Pantotheca acuminata and strain P1) were set up as controls. The absorbance value was measured by spectrophotometer, and the change in ammonia nitrogen concentration was calculated according to the standard curve.

[0061] (3) As can be seen from Table 5, each treatment group showed different degrees of ammonia nitrogen removal capacity during the cultivation process. Among them, the degradation effect of strain P1 was the most obvious. With the extension of cultivation time, the ammonia nitrogen degradation rate of group P1 gradually increased, and the ammonia nitrogen removal rate reached 31.93% after 16 hours. In contrast, the other denitrifying bacteria purchased had weaker denitrification capacity under low temperature and low carbon-to-nitrogen ratio conditions.

[0062] Table 5. Comparison of denitrification capacity and degradation rate of different bacteria under the same conditions.

[0063] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A type of Pseudomonas aeruginosa, taxonomically named Pseudomonas aeruginosa Its accession number is CCTCC M2026385.

2. A microbial preparation containing the Pseudomonas aeruginosa as described in claim 1.

3. The microbial preparation according to claim 2, characterized in that, The content of *Pseudomonas aeruginosa* in the microbial preparation is greater than or equal to 1 × 10⁻⁶. 6 CFU / mL or 1×10 6 CFU / g.

4. A composition containing the Pseudomonas aeruginosa of claim 1 or the microbial preparation of claim 2 or 3.

5. A river sewage treatment agent, characterized in that, The river wastewater treatment agent contains the Pseudomonas aeruginosa as described in claim 1, the microbial preparation as described in claim 2 or 3, or the composition as described in claim 4.

6. The application of the Pseudomonas aeruginosa of claim 1, the microbial preparation of claim 2 or 3, the composition of claim 4, or the river wastewater treatment agent of claim 5 in improving river water quality.

7. The application according to claim 6, characterized in that, The river water contains water with a dissolved oxygen concentration of less than 1 mg / L.

8. The application according to claim 6, characterized in that, The improvement of river water quality includes at least one of the following effects: (1) Reduce the chemical oxygen demand of river water; (2) Reduce the ammonia nitrogen content in river water; (3) Reduce the total nitrogen in the river water.

9. A method for treating river sewage, characterized in that, The method involves adding the Pseudomonas aeruginosa of claim 1, the microbial preparation of claim 2 or 3, the composition of claim 4, or the river wastewater treatment agent of claim 5 into the river for denitrification.

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