A type of Pseudomonas proteus, its inoculants and applications

Abstract

This invention provides a *Pseudomonas plecoglossicida* strain, its inoculant, and its applications, relating to the field of microbiology. Specifically, the *Pseudomonas plecoglossicida* NT strain, with accession number CGMCC No. 25090, can efficiently convert nitrate nitrogen, reduce the accumulation of nitrates in soil, and remediate secondary salinized soils. It also possesses the ability to produce extracellular polysaccharides, promoting the formation of soil aggregates and increasing soil cohesion. Furthermore, this strain can successfully colonize the rhizosphere soil of vegetables, improving the rhizosphere ecological environment, promoting vegetable growth, and increasing yield. This achieves the goal of ensuring both the sustainable development of modern agriculture and the quality and quantity of crops. The strain of this invention has relatively comprehensive soil remediation capabilities and has enormous application potential.

Description

Technical Field

[0001] This invention relates to the field of microbiology, specifically to a Pseudomonas proteus strain, its inoculants, and their applications. Background Technology

[0002] Nitrate accumulation is not only a major characteristic of secondary soil salinization but also a leading factor causing physiological disorders in crops. When soil salinization occurs, compaction occurs, and a noticeable white salt bloom appears on the soil surface when dry. Secondary soil salinization can lead to stunted growth, slow development, reduced yield, and even wilting and death in vegetables; it also causes fertilizer waste and contributes to agricultural non-point source pollution through surface runoff and seepage from farmland; and excessive nitrate intake can lead to NO accumulation in the body. 3- Easily reverts to NO 2- This causes oxygen deficiency in cells and tissues, and in severe cases, it can lead to suffocation and death.

[0003] Traditional methods for addressing secondary soil salinization include irrigation to leach salts, soil conditioners, semi-composted organic fertilizers, and planting salt-tolerant plant varieties. However, these methods can easily cause secondary pollution or reduce production efficiency and do not fundamentally solve the problem of secondary soil salinization. Utilizing microorganisms to remediate secondary soil salinization is the most effective approach.

[0004] Chinese patent document CN114031466A discloses a composite soil remediation agent suitable for saline-alkali land, which can achieve safe, fast and efficient remediation of saline-alkali soil, reduce remediation costs, reduce the occurrence of secondary pollution, significantly increase the yield of saline-alkali land, and significantly improve the quality of agricultural products. Chinese patent document CN113930345A discloses a moderately halophilic Fusarium oxysporum strain and its application, which relates to the field of saline-alkali land soil remediation technology. Chinese patent CN114250165A discloses a strain and a microbial agent containing the strain of the present invention that can be used for biological denitrification in high-salt environments, degradation, transformation and biological denitrification processes of pollutants under high-salt conditions, including high-salt wastewater treatment, seawater pollution treatment, saline-alkali land remediation, consumption of nitrogen nutrients, inhibition of excessive algal growth, water purification, and improvement of bottom sediment.

[0005] The strains disclosed in the aforementioned patent documents all possess some soil remediation capabilities, but they do not exhibit strong nitrate nitrogen conversion capabilities, and their soil remediation indicators are limited. Therefore, exploring a strain with relatively comprehensive soil remediation functions and strong nitrate nitrogen conversion capabilities is an urgent need for those skilled in the art. Summary of the Invention

[0006] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the existing soil remediation strains having weak nitrate nitrogen conversion ability and single soil remediation ability, thereby providing a Pseudomonas mutans, its inoculum and its application.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] In a first aspect, the present invention provides a *Pseudomonas proteus*, specifically *Pseudomonas proteus* (…). Pseudomonas plecoglossicida )NT, with accession number CGMCC No.25090.

[0009] The *Pseudomonas proteus* provided by this invention ( Pseudomonas plecoglossicida NT was deposited on June 16, 2022, at the China General Microbiological Culture Collection Center (CGMCC), located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, with accession number CGMCC No. 25090.

[0010] Secondly, the present invention provides a *Pseudomonas proteus* inoculum containing *Pseudomonas proteus* with accession number CGMCC No. 25090. Pseudomonas plecoglossicida NT.

[0011] Thirdly, the present invention provides the application of the aforementioned *Pseudomonas proteus* or the *Pseudomonas proteus* inoculum in soil nitrate nitrogen transformation.

[0012] Fourthly, the present invention provides the application of the aforementioned *Pseudomonas proteus* or the *Pseudomonas proteus* inoculant in promoting the formation of soil aggregates.

[0013] Fifthly, the present invention provides the application of the aforementioned *Pseudomonas proteus* or the *Pseudomonas proteus* inoculant in soil remediation.

[0014] Sixthly, the present invention provides the application of the aforementioned *Pseudomonas proteus* or the *Pseudomonas proteus* inoculant in vegetable cultivation.

[0015] Furthermore, the *Pseudomonas proteus* or *Pseudomonas proteus* inoculant is used to promote vegetable growth.

[0016] Furthermore, the vegetables include cucumbers and lettuce.

[0017] The technical solution of this invention has the following advantages:

[0018] The *Pseudomonas proteus* provided by this invention ( Pseudomonas plecoglossicidaNT can efficiently convert nitrate nitrogen, reduce the accumulation of nitrate in the soil, and remediate secondary salinized soil. It also has the ability to produce extracellular polysaccharides, promoting the formation of soil aggregates and increasing soil cohesion. Furthermore, this strain can successfully colonize the rhizosphere soil of vegetables, improving the rhizosphere ecological environment, promoting vegetable growth, and increasing yield. This ensures both the sustainable development of modern agriculture and the preservation of crop quality and quantity. In summary, the strain of this invention possesses relatively comprehensive soil remediation capabilities and has enormous application potential. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a cell morphology image of Pseudomonas mutabilis NT under an optical microscope, provided by the present invention.

[0021] Figure 2 This is a growth diagram of *Pseudomonas proteus* NT on a nitrate nitrogen qualitative detection medium provided by the present invention. Detailed Implementation

[0022] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0023] The inventors isolated a new bacterial strain from rhizosphere soil samples of cherry trees (collected from a cherry orchard in Shanhaiguan District, Hebei Province). The isolation process was as follows: 10g of soil was weighed, added to 100mL of water, and shaken at 200r / min for 30min. Then, 5mL of the sample was added to 45mL of sterile water to obtain 10g of the strain. -2 The diluent was diluted stepwise to obtain a 10-10 solution. -4 10 -5 10 -6 The diluted solution was then spread evenly onto NA solid medium plates (10g peptone, 3g beef meal, 5g NaCl, 20g agar, pH 7.2, 1L distilled water), and incubated at 30℃ for 1 day. Single colonies were picked and cultured on NA solid medium, then incubated at 30℃ for another day. Colony morphology was observed, and cell morphology was examined using an optical microscope.Figure 1 As shown, the bacteria are slightly curved or straight rod-shaped with blunt, rounded ends and are arranged in a dispersed manner.

[0024] The strain was identified as *Pseudomonas proteus*. Pseudomonas plecoglossicida It has been deposited at the China General Microbiological Culture Collection Center (CGMCC), located at No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing. The deposit date is June 16, 2022, and the accession number is CGMCC No. 25090.

[0025] The identification results of this strain, its physiological and biochemical properties, nitrate nitrogen conversion capacity, extracellular polysaccharide production, root colonization dynamics in vegetables, and its growth-promoting effects on vegetables will be described in detail below.

[0026] Where specific experimental steps or conditions are not specified in the embodiments, they can be performed according to the conventional experimental steps or conditions described in the literature in this field. All raw materials or instruments used are commercially available conventional products, including but not limited to those used in the embodiments of this application.

[0027] Example 1: Identification of Strains as Clones

[0028] DNA was extracted from *Pseudomonas proteus* NT using a TRAN genomic DNA extraction kit (Beijing TransGen Biotechnology). Primers were designed based on the most conserved sequence in bacterial 16S rDNA.

[0029] Primer 27F: 5'-AGA GTT TGA TCC TGG CTCA-3';

[0030] Primer 1492R: 5'-GGT TAC CTT GTT ACG ACTT-3'.

[0031] Primers were synthesized by Beijing Liuhe BGI Genomics Co., Ltd.

[0032] PCR reaction conditions: 94℃ for 4 min, 94℃ for 30 s, 60℃ for 30 s, 72℃ for 30 s, for 30 cycles, with a final extension at 72℃ for 10 min. The PCR amplification product was ligated to the plasmid at 25℃ for 15 min, followed by a 45 s heat shock in a water bath and transformation into competent *E. coli* cells for cloning. Strains containing the target gene were obtained through blue-white screening and sent to Beijing BGI Genomics Co., Ltd. for sequencing.

[0033] After bidirectional splicing of the NT sequencing results, the resulting 16S rDNA sequence was compared with the NCBI website, and the result was Pseudomonas proteobacterium. Pseudomonas plecoglossicida The homology is 100%.

[0034] The 16S rDNA sequence is shown in SEQ ID No. 1:

[0035]

[0036] Example 2: Physiological and Biochemical Identification of Strains

[0037] Physiological and biochemical identification was performed with reference to the relevant contents of the "Manual of Systematic Identification of Common Bacteria" and "Bergey's Manual of Bacterial Identification (8th Edition)".

[0038] Pseudomonas proteus NT is a Gram-negative bacterium, consisting of small rod-shaped cells without flagella, measuring 0.5–0.7 μm × 2–3 μm.

[0039] The physiological and biochemical characteristics of *Pseudomonas proteus* NT are shown in Table 1, and the utilization capacity of *Pseudomonas proteus* NT for 95 carbon source substrates on BIOLOG plates is shown in Table 2.

[0040] Table 1. Physiological and biochemical characteristics of *Pseudomonas proteus* NT.

[0041]

[0042] Note: "+" indicates a positive reaction, "-" indicates a negative reaction, and " / " indicates a critical state.

[0043] Table 2. Utilization of carbon source substrates by *Pseudomonas proteus* NT.

[0044]

[0045] Note: "+" indicates a positive reaction, "-" indicates a negative reaction, and " / " indicates a critical state.

[0046] Example 3: Detection of Nitrate Nitrogen Conversion Capacity of Strains

[0047] I. Qualitative Detection of Nitrate Nitrogen Conversion Capacity

[0048] 1. Detection Method

[0049] Pseudomonas mutans NT was activated onto a nitrate-converting bacteria selection medium and cultured at the optimal growth temperature for 2 days. The ability of the strain to convert nitrate nitrogen was determined based on its growth status on the plate.

[0050] Nitrate-converting bacteria screening medium: KNO3 10.0g, KCl 1.0g, FeSO4·7H2O 10.0mg, MgSO4·7H2O 0.5g, CaCl2 1.0mg, KH2PO4 0.5g, glucose 7.5g, agar 15.0g, distilled water 1000mL, pH 7.0.

[0051] 2. Results

[0052] like Figure 2As shown, *Pseudomonas proteus* NT grew well on the nitrate nitrogen qualitative detection medium, with a large bacterial count, proving that this strain has the ability to convert nitrate nitrogen.

[0053] II. Determination of Nitrate Nitrogen Conversion Capacity in Water Bodies

[0054] 1. Detection Method

[0055] Using potassium nitrate standard solutions with concentrations of 0 mg / L, 0.05 mg / L, 0.1 mg / L, 0.25 mg / L, 0.5 mg / L, and 1.00 mg / L, the absorbance A at 220 nm and 275 nm was measured, and A was calculated. 校 =A 220 -2A 275 Draw a standard curve.

[0056] Pseudomonas proteus NT was inoculated into inorganic salt liquid medium. Bacterial culture was collected on days 3 and 5, centrifuged at 3000 rpm for 5 min, and OD was measured. 600 Calculate the corrected absorbance using absorbance at 220 nm and 275 nm, and obtain the nitrate nitrogen content based on the standard curve.

[0057] Nitrate nitrogen conversion rate (%) = (Initial nitrate nitrogen content in the culture medium - Residual nitrate nitrogen content in the culture medium) / Initial nitrate nitrogen content in the culture medium × 100%

[0058] Inorganic salt liquid culture medium (nitrate nitrogen content 500 mg / L): KNO3 3.6 g, sucrose 13.3 g, KCl 1.0 g, FeSO4·7H2O 10.0 mg, MgSO4·7H2O 0.5 g, CaCl2 1.0 mg, KH2PO4 0.5 g, glucose 7.5 g, agar 15.0 g, distilled water 1000 mL, pH 7.0.

[0059] 2. Results

[0060] Table 3. Nitrate nitrogen conversion rate in water bodies

[0061]

[0062] During liquid quantitative detection, the nitrate nitrogen content in the culture medium on day 5 decreased by 405.37 mg / L compared with the initial value, which means that the nitrate nitrogen conversion of Pseudomonas proteus NT can reach more than 400 mg / L.

[0063] III. Determination of Nitrate Nitrogen Transformation Capacity in Soil

[0064] 1. Detection Method

[0065] Weigh 0.72 g of KNO3 (dry at 105~110℃ for 2 h), dilute to 1000 mL in a volumetric flask, shake well, and store at 0~4℃ to obtain the nitrate nitrogen standard stock solution.

[0066] Take 10 mL of the above nitrate nitrogen standard stock solution and dilute to 100 mL in a volumetric flask. Shake well to obtain the nitrate nitrogen standard intermediate solution.

[0067] Pipette 0 mL, 0.5 mL, 1 mL, 2 mL, 3 mL, and 4 mL of nitrate nitrogen standard intermediate solution into 100 mL volumetric flasks, dilute to volume with 1 mol / L KCl solution, and shake well to obtain nitrate nitrogen standard working solutions with concentrations of 0 mg / L, 0.05 mg / L, 0.1 mg / L, 0.2 mg / L, 0.3 mg / L, and 0.4 mg / L.

[0068] Using a quartz cuvette with a 10 mm optical path length, the absorbance of the nitrate nitrogen standard working solution was measured at 220 nm and 275 nm using a 1 mol / L KCl solution as a reference solution on a UV spectrophotometer (Shanghai Instrument & Electronics). The corrected absorbance was calculated: A 校 =A 220 -2A 275 .

[0069] Soil from within the park was naturally air-dried and passed through a 20-mesh sieve. The initial nitrate nitrogen value was determined to be 15 mg / kg. KNO3 (dried at 105~110℃ for 2 hours) was added to the test soil and mixed thoroughly to bring the nitrate nitrogen content to the set value (500 mg / kg). Pseudomonas proteans NT was inoculated and 1% glucose was added as a carbon source. The change in nitrate nitrogen in the soil was then measured.

[0070] 2. Results

[0071] Table 4 Nitrate nitrogen conversion rate in soil

[0072]

[0073] The amount of nitrate nitrogen transformed by *Pseudomonas proteus* NT in soil was approximately 500 mg / kg (conversion rate close to 100%). Compared with *Bacillus megaterium* (nitrate nitrogen transformation amount in soil was 91 mg / kg) reported in existing literature (Zhang Chunhua. Screening and identification of nitrate nitrogen transforming bacteria and their transformation efficiency study [D]. Shanghai Jiaotong University, 2011.), *Pseudomonas proteus* NT showed more outstanding soil remediation indicators.

[0074] Example 4: Detection of Extracellular Polysaccharide Yield of Strains

[0075] Soil aggregate capacity (the ability to form soil aggregates) is related to extracellular polysaccharides and is an important indicator of soil remediation agents. This embodiment aims to detect whether *Pseudomonas proteus* NT has the ability to produce extracellular polysaccharides.

[0076] 1. Detection Method

[0077] ①Precipitate crude polysaccharides

[0078] *Pseudomonas proteus* NT was inoculated into extracellular polysaccharide detection medium (10g glucose, 5g tryptone, 1g yeast extract, 3g K2HPO4, 1g KH2PO4, 0.5g MgSO4, pH 7.0, 1L water) and cultured at 37℃ with shaking at 200rpm / min. Fermentation broths from different culture times were centrifuged at 8000r / min for 10min, and 10mL of supernatant was collected. Three volumes of 95% ethanol were added, and the mixture was incubated overnight at 4℃. After centrifugation at 8000r / min for 10min, the precipitate was washed three times with 80% ethanol, and water was added to a final volume of 10mL to prepare the test solution.

[0079] ② Creating a standard curve

[0080] Prepare a 40 mg / L glucose standard solution. Take 0.4 mL, 0.6 mL, 0.8 mL, 1.0 mL, 1.2 mL, 1.4 mL, 1.6 mL, and 1.8 mL of the standard solution respectively, add water to make up to 2.0 mL, add 1.0 mL of 6% phenol and 5.0 mL of concentrated sulfuric acid, let stand for 10 min, shake well, and let stand at room temperature for 20 min. Measure the optical density at 490 nm. Use 2.0 mL of water as a blank for the same color development. Plot a standard curve with polysaccharide micrograms on the x-axis and optical density value on the y-axis.

[0081] ③ Sample content determination

[0082] Take sample solutions with different dilution ratios, measure the optical density using the same colorimetric method described above, and calculate the polysaccharide content using a standard curve.

[0083] 2. Results

[0084] The extracellular polysaccharide content of *Pseudomonas proteus* culture media after 4, 9, and 11 days of NT culture was determined, and the results are as follows:

[0085] Table 5 Extracellular polysaccharide production

[0086]

[0087] Pseudomonas proteus NT has the ability to produce extracellular polysaccharides, with a yield of 163.49 mg / L after 11 days of culture, which can promote the formation of soil aggregates.

[0088] Example 5: Dynamic detection of bacterial colonization in vegetable roots

[0089] 1. Detection Method

[0090] ①Preparation of bacterial culture

[0091] An appropriate amount of activated *Pseudomonas proteus* NT cells was inoculated into 100 mL of liquid culture medium (5 g yeast extract, 10 g tryptone, 10 g NaCl, pH 7.2, 1 L distilled water). The culture was incubated at 30°C and 200 rpm for 24 h to obtain a seed culture. The seed culture was then inoculated into 100 mL of liquid culture medium at a 1‰ inoculation rate and incubated at 30°C and 200 rpm for 48 h. The OD values ​​were adjusted with sterile water to ensure uniformity before use.

[0092] ② Seed treatment

[0093] Soak cucumber and lettuce seeds in 50℃ warm water for 10 minutes, disinfect with 1% sodium hypochlorite solution for 3 minutes, rinse with sterile water 3-5 times, and air dry. Soak the seeds in the bacterial suspension prepared in step ① at a ratio of 1:50, with a control of soaking in liquid culture solution. After air drying at room temperature, divide the seeds into two portions. Use the plate count method to determine the initial bacterial load in one portion, and use the other portion for sowing.

[0094] ③ Determination of initial bacterial load in seeds

[0095] Take 20 cucumber and 20 lettuce seeds each that have been treated with the bacterial solution, and place them in Erlenmeyer flasks containing 50 mL of sterile water. Shake at 200 r / min for 30 min on a shaker. After serial dilution with sterile water, take 0.1 mL and spread it on a culture medium plate. Repeat each treatment 3 times. After incubation at 30℃ for 2 days, count the initial bacterial load on the seeds using the plate count method.

[0096] ④ Sowing and Management

[0097] Seeds treated with the bacterial solution were planted in sterilized nutrient soil (composed of perlite, vermiculite, and peat moss, containing 14.85% organic matter, 0.4% total nitrogen, 2.62% total potassium, 0.16% total phosphorus, and a pH of 6.24), with seeds soaked in the culture solution serving as a control. Six pots were used per treatment, with 20 seeds per pot. The plants were incubated at room temperature (20–25°C) and watered regularly (100 mL / pot, once a week). Plant growth was observed after germination, and samples were taken starting on the 6th day after emergence.

[0098] ⑤ Testing

[0099] Shake off large clumps of soil from the roots, leaving the attached soil. Weigh the sample and place it in an Erlenmeyer flask containing 50 mL of sterile physiological saline. Shake at 200 rpm for 30 min on a shaker. Serially dilute with sterile water. Take 0.1 mL of different concentrations of the diluted solution and spread it on a culture medium plate. Repeat each treatment 3 times. After incubating at 30℃ for 2 days, isolate the control plants in the same way as above. Use the plate count method to detect the colonization of the labeled strain in the rhizosphere of cucumber and lettuce.

[0100] 2. Test Results

[0101] ① Colonization dynamics of the strain in cucumber roots

[0102] The colonization rate of *Pseudomonas proteus* NT in cucumber roots is shown in the table below. The colonization rate reached its peak on day 7, and then showed a downward trend on day 21, decreasing by one order of magnitude by day 42.

[0103] Table 6. Colonization dynamics of the strain in cucumber roots

[0104]

[0105] ② Colonization dynamics of the bacterial strain in lettuce roots

[0106] The colonization of *Pseudomonas proteus* NT in lettuce roots is shown in the table below. The overall trend is a gradual decrease, with a decrease of two orders of magnitude after 42 days.

[0107] Table 7. Colonization dynamics of the strains in lettuce roots

[0108]

[0109] This demonstrates that *Pseudomonas proteus* NT can successfully colonize the roots of cucumbers and lettuce.

[0110] Example 6: Detection of the growth-promoting effect of the strain on vegetables

[0111] 1. Detection Method

[0112] ① The growth-promoting effect of the strain on cucumbers

[0113] Each greenhouse plot is 4.5m long and 3.5m wide, with an area of ​​15.75m². 2 The plants are arranged randomly. Each plot has 6 rows, with 10 plants per row (equivalent to 38,000 plants / hm²). 2 ), 15 days after transplanting, root irrigation was performed: the control group received 30 mL / plant of liquid culture medium (5 g yeast powder, 10 g tryptone, 10 g NaCl, pH 7.2, 1 L distilled water); the experimental groups were irrigated with an equal volume of bacterial suspension (10 viable bacteria). 8 The solution is irrigated once every 10 days for a total of 3 times (cfu / mL) to enhance bacterial colonization in the rhizosphere. Other management measures are the same as those in the local cold greenhouse.

[0114] Select the middle four rows (excluding the outer rows) as test samples, plant them for 60 days, and measure plant height, stem diameter, and single leaf area.

[0115] ② The growth-promoting effect of bacterial strains on lettuce

[0116] Each greenhouse plot is 4.5m long and 3.5m wide, with an area of ​​15.75m². 2The seeds were randomly arranged. Each plot had 10 rows, with seeds sown in each row. Later, thinning was carried out to a spacing of 15cm between each seedling. Twenty days after planting, the roots were irrigated: the control group received 30mL of liquid culture medium per seedling; the experimental groups received an equal volume of bacterial suspension (103 viable bacteria) as a root irrigation. 8 The solution is irrigated once every 10 days for a total of 3 times (cfu / mL) to enhance bacterial colonization in the rhizosphere. Other management measures are the same as those in the local cold greenhouse.

[0117] The middle 8 rows (excluding the edge rows) were selected as test samples. After 60 days of planting, plant height, stem diameter, single leaf area, and number of leaves were measured.

[0118] 2. Test Results

[0119] ① The growth-promoting effect of the strain on cucumber

[0120] The effects of *Pseudomonas proteus* NT on cucumber plant height, stem diameter, and single leaf area are shown in the table below:

[0121] Table 8. Growth-promoting effects of Pseudomonas proteus NT on cucumber.

[0122]

[0123] Note: P<0.05, different lowercase letters in the same column indicate significant differences.

[0124] ② The growth-promoting effect of bacterial strains on lettuce

[0125] The effects of *Pseudomonas proteus* NT on the growth promotion of lettuce plant height, stem diameter, single leaf area, and leaf number are shown in the table below:

[0126] Table 9. Growth-promoting effects of Pseudomonas proteus NT on lettuce

[0127]

[0128] Note: P<0.05, different lowercase letters in the same column indicate significant differences.

[0129] It can be seen that *Pseudomonas proteus* NT has a significant growth-promoting effect on the plant height and leaf area of ​​lettuce, but has little effect on stem diameter and leaf number; it also has a significant growth-promoting effect on the plant height, stem diameter, and leaf area of ​​cucumber, with increases of 18.80%, 13.40%, and 22.82%, respectively.

[0130] In summary, the *Pseudomonas mutabilis* NT provided by this invention can improve the ecological environment of plant rhizosphere by converting nitrate nitrogen, while producing extracellular polysaccharides to enhance soil cohesion. It has a relatively comprehensive soil remediation function, ensuring the sustainable development of modern agriculture while maintaining the quality and quantity of crops.

[0131] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A Pseudomonas plecoglossicida (P. plecoglossicida) strain, characterized in that, Pseudomonas plecoglossicida The specific *Pseudomonas proteus* is *Pseudomonas proteus* NT, with accession number CGMCC No. 25090. ​ 2. A Pseudomonas proteus inoculant, characterized in that, Contains *Pseudomonas proteus* with accession number CGMCC No. 25090. Pseudomonas plecoglossicida NT.

3. The application of the *Pseudomonas proteus* of claim 1 or the *Pseudomonas proteus* inoculum of claim 2 in soil nitrate nitrogen transformation.

4. The use of the *Pseudomonas proteus* of claim 1 or the *Pseudomonas proteus* agent of claim 2 in promoting the formation of soil aggregates.

5. The application of *Pseudomonas proteus* as described in claim 1 or *Pseudomonas proteus* inoculant as described in claim 2 in soil remediation, characterized in that... The soil remediation involves converting soil nitrate nitrogen and / or promoting the formation of soil aggregates.

6. The application of the *Pseudomonas proteus* of claim 1 or the *Pseudomonas proteus* inoculant of claim 2 in promoting vegetable growth, characterized in that, The vegetable in question is either cucumber or lettuce.

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