Heterotrophic nitrification-aerobic denitrification acinetobacter acinetobacter C24 and application thereof in sewage treatment

Abstract

The invention discloses a heterotrophic nitrification-aerobic denitrification acinetobacter acinetobacter strain C24 and an application of the heterotrophic nitrification-aerobic denitrification acinetobacter acinetobacter strain C24 in sewage treatment. The acinetobacter nosocomilates C24 strain provided by the invention has the capability of rapidly removing nitrogen and phosphorus under the condition of high-concentration inorganic nitrogen, has relatively good stability, and can grow by utilizing a plurality of carbon sources, so that the applicability of the acinetobacter nosocomilates C24 strain in different sewage environments is enhanced. Meanwhile, the nitrification and denitrification efficiency of C24 can be remarkably improved by optimizing treatment conditions, the removal rate of nitrate nitrogen, nitrite nitrogen, ammonium nitrogen and phosphate is remarkable, 99.9% of nitrate nitrogen, 99.5% of nitrite nitrogen, 96.67% of ammonium nitrogen and 98.54% of phosphate in water can be remarkably removed within 12 h, and an efficient, economical and environment-friendly new way is provided for sewage treatment.

Description

Technical Field

[0001] The present invention belongs to the technical field of microorganisms and wastewater treatment, and more specifically, relates to a heterotrophic nitrification-aerobic denitrification Acinetobacter nosocomial C24 strain and its application in sewage treatment. Background Art

[0002] In modern society, with the growth of population and rapid industrial development, water pollution is becoming increasingly serious, especially nitrogen and phosphorus pollution, which has caused significant damage to the water ecological environment. Nitrogen and phosphorus are the main factors of eutrophication of water bodies. Excessive nitrogen and phosphorus will lead to excessive growth of algae and other aquatic plants, consume dissolved oxygen in water, destroy the ecological balance of water bodies, and cause environmental problems such as algal blooms and red tides. Therefore, effectively removing nitrogen and phosphorus from sewage is of great significance for protecting water resources and improving the water environment.

[0003] As an important facility for controlling nitrogen and phosphorus pollution in water bodies, the treatment efficiency of sewage treatment plants is directly related to the quality of the water environment and ecological safety. However, traditional nitrogen and phosphorus removal technologies have many shortcomings. Although physical and chemical methods, such as chemical precipitation, adsorption and membrane technology, can remove nitrogen and phosphorus to a certain extent, these methods are complex to operate, costly, and may cause secondary pollution, which is not conducive to the sustainable development of the environment. Therefore, people gradually turn their attention to biological treatment technology to seek more economical, efficient and environmentally friendly solutions.

[0004] Biological denitrification technology is an important technology in the field of sewage treatment. It mainly relies on the metabolic activities of microorganisms to achieve the conversion and removal of nitrogen. In the traditional biological denitrification process, nitrogen removal mainly relies on two processes: aerobic nitrification and anoxic denitrification. In the aerobic nitrification process, ammonia nitrogen (NH 4 + -N) is converted into nitrate (NO) under aerobic conditions 3 - -N; in the anoxic denitrification process, nitrate is converted into nitrogen gas (N 2 ) and released into the atmosphere. These two processes usually need to be carried out in two separate reactors, and the aerobic and anoxic conditions need to be strictly controlled, which is complicated to operate and has high energy consumption.

[0005] In recent years, the discovery of heterotrophic nitrification-aerobic denitrification bacteria (HN-AD) has provided a new perspective for wastewater treatment. This type of bacteria can simultaneously carry out nitrification and denitrification processes under aerobic conditions to achieve efficient nitrogen removal. Compared with traditional biological denitrification processes, HN-AD bacteria simplify the treatment process, reduce energy consumption, and improve treatment efficiency. However, most known HN-AD bacteria do not perform well in phosphorus removal, and their adaptability and stability in high-concentration inorganic nitrogen environments need to be improved. Therefore, it is urgent to develop more microbial strains that can efficiently remove phosphorus and treat high-concentration nitrogen for wastewater treatment. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the defects and shortcomings of the existing HN-AD bacteria, and to provide a heterotrophic nitrification-aerobic denitrification nosocomial Acinetobacter C24 strain and its application in sewage treatment.

[0007] The first object of the present invention is to provide Acinetobacter nosocomialis C24 strain.

[0008] The second object of the present invention is to provide applications of the C24 strain and its bacterial solution.

[0009] The third object of the present invention is to provide a microbial agent.

[0010] A fourth object of the present invention is to provide a product.

[0011] A fifth object of the present invention is to provide a sewage treatment method.

[0012] The sixth object of the present invention is to provide a method for improving the efficiency of removing nitrogen and / or phosphorus from sewage by using C24 strain or its bacterial solution.

[0013] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0014] The present invention provides an Acinetobacter nosocomialis C24 strain, which was deposited in Guangdong Provincial Microbiological Culture Collection Center on November 27, 2024, with a deposit number of GDMCC NO: 65597.

[0015] The present invention isolates and identifies a new heterotrophic nitrifying aerobic denitrifying bacterium, Acinetobacter nosocomialis C24 strain, which is a Gram-negative bacillus, aerobic, rod-shaped or short rod-shaped, without spores; the colonies on the enrichment medium plate are off-white, round, convex, smooth and moist, opaque, with neat edges; and have no hemolytic activity. Studies have shown that the C24 strain not only has excellent nitrogen removal ability, but can also efficiently remove ammonia nitrogen, nitrate nitrogen and nitrite nitrogen. Within 12 hours, NH 4 + The removal efficiency of -N can reach 96.67%, and the average removal rate is 12.616 mg / L / h; NO 3 - -N removal efficiency reached 99.9%, and the average removal rate was 14.8303 mg / L / h; NO 2 - -N removal efficiency reaches 99.5%, with an average removal rate of 8.3597 mg / L / h, and it can also handle high-concentration inorganic nitrogen; effectively remove phosphorus under aerobic conditions, and remove PO 4 3- The removal efficiency of -P reaches 98.54%, and the average removal rate is 2.1778 mg / L / h. It can be used to remove inorganic nitrogen and phosphate pollutants in water bodies and significantly remove nitrogen and / or phosphorus in sewage.

[0016] Therefore, the present invention provides the use of C24 strain or its bacterial liquid in removing nitrogen and / or phosphorus from sewage, in preparing products for removing nitrogen and / or phosphorus from sewage, in sewage treatment, in removing ammonia nitrogen, nitrate nitrogen and nitrite nitrogen from sewage, or in removing inorganic nitrogen and phosphate pollutants in water bodies.

[0017] The invention provides a microbial agent, which contains a C24 strain or a bacterial solution thereof.

[0018] Preferably, the present invention also provides a method for preparing a microbial agent: inoculate the hospital-acinetobacter C24 in an activation medium and activate it in a shaker at 37°C until it grows to a logarithmic phase. Then, inoculate 5% of the activated bacterial solution by volume into 50 mL of a nitrification medium and culture for 12 hours. The culture conditions are strictly controlled at 37°C and the shaker speed is 180 r / min.

[0019] The present invention provides a product containing the above-mentioned bacterial agent.

[0020] At the same time, the present invention provides an efficient, economical and environmentally friendly sewage treatment method, which uses the C24 strain or its bacterial solution to treat sewage. Under aerobic conditions, the C24 strain can simultaneously carry out nitrification and denitrification reactions to achieve efficient removal of nitrogen and phosphorus, and can achieve polyphosphate under fully aerobic conditions without alternating anaerobic / aerobic conditions. In addition, it has good adaptability to high-concentration inorganic nitrogen and can maintain stable nitrogen removal and phosphorus removal performance when the carbon source is insufficient. The C24 strain can also use a variety of carbon sources for growth, which enhances its applicability in different sewage environments.

[0021] Therefore, the present invention provides a sewage treatment method, which uses the C24 strain or its bacterial liquid to treat sewage, or adds the above product to sewage, and inoculates the nosocomial Acinetobacter C24 into the nitrogen and phosphorus-containing wastewater, thereby utilizing its heterotrophic nitrification, aerobic denitrification and phosphorus accumulation effect to effectively remove nitrogen and phosphorus in the wastewater.

[0022] In addition, the study found that copper and iron metal ions have a significant promoting effect on the denitrification function of C24 bacteria. Through in-depth research and optimization of the application of metal ion concentration in sewage treatment, by precisely controlling the concentration of metal ions such as iron and copper, adding trace amounts of Fe 3+ / Cu 2+ Ions can not only improve its denitrification efficiency and significantly enhance the nitrogen and phosphorus removal capabilities of nosocomial Acinetobacter C24, but also avoid microbial toxicity problems caused by excessive metal ions.

[0023] Therefore, the present invention also provides a method for efficiently removing nitrogen and / or phosphorus from sewage by using a C24 strain or its bacterial solution, wherein 0.5 to 2 mg / L Fe 3+ / Cu 2+ Ions can promote the heterotrophic nitrification and aerobic denitrification capabilities of C24 strains.

[0024] In particular, when the C24 strain is used in a wastewater treatment system to treat wastewater, the carbon source, C / N ratio, P / N ratio, salinity, initial NH 4 + -N concentration and other parameter values, in order to further improve the removal effect of nitrogen and phosphorus, need to be set according to the actual operating system.

[0025] The present invention has the following beneficial effects:

[0026] The nosocomial Acinetobacter C24 strain isolated and identified by the present invention has the following advantages:

[0027] (1) Efficient nitrogen removal ability: The C24 strain provided by the present invention can use ammonia nitrogen, nitrate nitrogen and nitrite nitrogen as the only nitrogen source for growth, and achieve the simultaneous removal of ammonia nitrogen and nitrate nitrogen. In the shake flask experiment, the C24 strain showed excellent nitrogen removal efficiency, and its nitrate nitrogen and nitrite nitrogen removal rates reached 99.9% and 99.5% respectively within 12 hours.

[0028] (2) Strong environmental adaptability: The C24 strain provided by the present invention can still maintain the ability to remove nitrogen and phosphorus in a water environment with insufficient carbon source, which verifies its strong environmental adaptability. In various simulated sewage, the C24 strain can maintain stable nitrogen and phosphorus removal performance, which provides a solid foundation for its wide application in the field of sewage treatment.

[0029] (3) Simplified culture process: The culture medium components required for the activation and expansion of the C24 strain provided by the present invention are simple, and the bacterial liquid preparation process is relatively easy, which greatly reduces the cost and complexity of industrial production. The simplified process is not only conducive to improving production efficiency, but also convenient for implementation in sewage treatment facilities of different scales.

[0030] (4) Metal ion-promoting denitrification effect: The present invention further improves the denitrification efficiency of the C24 strain. Under appropriate copper / iron ion concentrations, it can further increase the removal rates of nitrate nitrogen, nitrite nitrogen, ammonium nitrogen and phosphate, and has no negative impact on the growth and metabolic activity of the strain.

[0031] (5) Improvement of sewage treatment efficiency: The C24 strain and its metal ion optimization strategy provided by the present invention significantly improve the treatment efficiency of sewage treatment plants in terms of nitrogen and phosphorus removal. This not only helps to reduce the operating costs of sewage treatment, but also improves the effluent quality and meets more stringent environmental protection standards. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The following are the morphological pictures of the activation culture medium plate of the C24 strain and the pictures taken under an optical microscope (×100).

[0033] Figure 2 This is the phylogenetic tree of strain C24.

[0034] Figure 3 The hemolytic test results of strain C24.

[0035] Figure 4 The degradation capacity of strain C24 for ammonia nitrogen (a), nitrate nitrogen (b), nitrite nitrogen (c) and phosphate (d).

[0036] Figure 5 For C24 strains with different Fe 3+ / Cu 2+Nitrogen and phosphorus removal characteristics under the conditions of ion concentration (ac), different carbon sources (d), C / N ratio (e), salinity (f), different initial ammonia nitrogen concentrations (g) and P / N (h) ratio. DETAILED DESCRIPTION

[0037] The present invention is further described below in conjunction with the accompanying drawings and specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0038] Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0039] The components of the culture medium and simulated sewage used in the examples are as follows, and all the culture media used are sterilized before use:

[0040] LB medium: 10 g of tryptone, 5 g / L yeast extract, 10 g of sodium chloride, dilute to 1 L with ultrapure water, and adjust the pH to 7.0.

[0041] Enrichment medium: 10.0 g tryptone, 5.0 g anhydrous glucose, 3.0 g beef extract, 5.0 g NaCl, dilute to 1 L with ultrapure water, pH 7.0-7.4, add 18 g agar to the solid medium.

[0042] BTB medium: aspartic acid 1.0 g, potassium nitrate 1.0 g, potassium hydrogen phosphate 1.0 g, calcium chloride 0.3 g, ferrous sulfate hexahydrate 0.05 g, magnesium sulfate heptahydrate 1.0 g, 1% bromothymol blue 1 mL, agar 18.0 g, ultrapure water to 1 L, pH 7.1-7.2.

[0043] Heterotrophic nitrification medium: 4.052 g sodium succinate, 0.472 g ammonium sulfate, 1 g potassium dihydrogen phosphate, 1 g magnesium sulfate, 50 mL Weiss solution, 950 mL ultrapure water, pH 7.0. Add 18 g agar powder to the heterotrophic nitrification solid medium.

[0044] Aerobic denitrification medium: 0.72 g potassium nitrate, 1 g potassium dihydrogen phosphate, 1 g magnesium sulfate, 2.8 g sodium succinate, 50 mL Weiss solution, 950 mL ultrapure water, pH 7.0. Add 18 g agar powder to the aerobic denitrification solid medium.

[0045] Weiss solution: 5.0 g potassium dihydrogen phosphate, 2.5 g magnesium chloride hexahydrate, 2.5 g sodium chloride, 0.05 g ferrous sulfate heptahydrate, 0.05 g copper sulfate, and ultrapure water to 1 L, pH 7.0.

[0046] Nitrate denitrification simulated sewage: 0.05g calcium chloride, 5.0g sodium chloride, 1.5g sodium acetate, 0.15g potassium nitrate, 0.03g potassium dihydrogen phosphate, 0.05g magnesium sulfate heptahydrate, 2mL trace elements, 998mL ultrapure water.

[0047] Nitrite denitrification simulated sewage: calcium chloride 0.05g, sodium chloride 5.0g, sodium acetate 1.0g, sodium nitrite 0.1g, potassium dihydrogen phosphate 0.03g, magnesium sulfate heptahydrate 0.05g, trace elements 2mL, ultrapure water 998mL.

[0048] Ammonium salt nitrification simulated sewage: calcium chloride 0.05g, sodium chloride 5.0g, sodium acetate 1.5g, ammonium chloride 0.15g, potassium dihydrogen phosphate 0.03g, magnesium sulfate heptahydrate 0.05g, trace elements 2mL, ultrapure water 998mL.

[0049] Trace elements: EDTA 1.0g, zinc sulfate 0.2g, magnesium sulfate heptahydrate 0.5g, cupric chloride tetrahydrate 0.1g, ferrous sulfate heptahydrate 0.5g, anhydrous copper sulfate 0.5g, cobalt chloride hexahydrate 0.2g, ultrapure water 1L.

[0050] Example 1 Isolation and identification of strains

[0051] 1. Isolation and screening of strains

[0052] Take 10mL of sewage from an aerobic pool of a horizontal sewage treatment plant in Guangzhou, add it to 50mL of enrichment culture medium, and culture it at 37℃ for 24h with a shaker speed of 180rpm. Transfer it with fresh screening culture medium every 24h, and then culture it at 37±2℃ for 24h until NO 3 - The -N removal rate was stably above 90%. The suspension was then evenly spread on a bromothymol (BTB) plate and cultured at 37°C for 48 hours until visible blue colonies appeared on the plate. During the screening process, each culture medium and simulated sewage were sterilized before use.

[0053] To further purify the colonies, streaking was repeated several times on heterotrophic nitrification medium (18 g / L agar) with nitrate as the only nitrogen source, and the purified strains were transferred into simulated sewage with nitrate as the only nitrogen source and ammonia as the only nitrogen source to select NO 3 - -N, NH 4 + -N and PO 4 3- -The strains with high P removal rate were used to obtain heterotrophic nitrification-aerobic denitrification bacteria.

[0054] Subsequently, the strains obtained from the preliminary screening were tested for their aerobic nitrogen and phosphorus removal performance using nitrate nitrogen as the only nitrogen source culture medium, and the strain with excellent performance was selected and named C24 strain, which was used as the target strain for subsequent research.

[0055] 2. Morphological identification of strains

[0056] The C24 strain was then subjected to morphological identification. The colony morphology of the C24 strain was observed. The colonies were light gray in appearance, with regular round edges, and the surface of the colonies was usually moist, smooth, and relatively sticky. Figure 1 As shown, Gram staining was negative, and under the microscope it could be observed that the bacteria were short rod-shaped and densely distributed.

[0057] 3. Molecular biological identification of strains

[0058] The purified C24 strain was inoculated into LB medium and cultured at 120r / min and 37°C for more than 12h. The bacterial solution was used as a template and the universal primer pair 27F / 1492R was used for PCR amplification. The reaction conditions were pre-denaturation at 95°C for 5min, denaturation at 94°C for 37s, renaturation at 57°C for 37s, extension at 72°C for 90s, 37 cycles, extension at 72°C for 5-10min, and storage at 4°C for 15min. The 16S rRNA product obtained by PCR amplification was sequenced for the first generation, and the sequence obtained by sequencing was submitted to the NCBI website for comparison and analysis with the existing strain data in the GenBank database. The strains with higher similarity were searched using BLAST, and then the MEGA11.0 software was used to select the Neighbor Joining method to construct a phylogenetic tree.

[0059] The sequencing results showed that the 16S rRNA sequence of strain C24 is shown in SEQ ID NO.1, and the phylogenetic tree of strain C24 is shown in Figure 2 As shown, the homology between strain C24 and Acinetobacter nosocomialis strain RUH 237623 is as high as 99.86%. Combining the results of morphological and molecular biological identification, the taxonomic status of strain C24 was attributed to Acinetobacter nosocomialis, and it was deposited in Guangdong Microbiological Culture Collection Center on November 27, 2024, with the deposit number GDMCC NO: 65597, and the deposit address is 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou.

[0060] Example 2 Strain Performance Test

[0061] 1. Hemolytic test

[0062] Activate the C24 strain in LB medium for two generations, collect the activated bacterial liquid, and perform the spot plate method. Spot 10 μL of the bacterial liquid with OD 600 = 0.8 on a Columbia blood agar plate three times to ensure three parallels. After the bacterial liquid dries naturally, place the plate in an incubator at 37 °C for 24 h and then observe the results.

[0063] The measurement results are as Figure 3 shown, indicating that the C24 strain has good biosafety and no hemolytic activity.

[0064] 2. Antibiotic sensitivity

[0065] Activate the C24 strain in LB medium for two generations and collect the activated bacterial liquid. Spread 100 μL of the bacterial liquid with OD 600 = 0.8 on the LB medium. After the bacterial liquid dries naturally, use sterile forceps to place drug sensitivity test strips containing different antibiotics on the plate. Place three drug sensitivity test strips on each plate to ensure three parallels. Place the plate in an incubator at 37 °C for 24 h and then measure the inhibition diameter.

[0066] The measurement results are shown in Table 1, indicating that the C24 strain is sensitive to most antibiotics, such as penicillins, cephalosporins, aminoglycosides, fluoroquinolones, macrolides, tetracyclines, phenylpropanols, and sulfonamides, suggesting that this microorganism is easily controlled by antibiotics.

[0067] Table 1 Sensitivity test of C24 to antibiotics

[0068]

[0069] Note: S: The strain is sensitive to the antibiotic; I: The strain is intermediately sensitive to the antibiotic; R: The strain is insensitive to the antibiotic.

[0070] Example 3 Denitrification performance test of the strain

[0071] 1. Denitrification performance when ammonia nitrogen is used as the sole nitrogen source

[0072] Inoculate the Acinetobacter nosocomialis C24 strain obtained in Example 1 into LB medium, and then place it in a shaker at 37 °C for activation. After it grows to the logarithmic phase, inoculate 5% of the activated bacterial liquid by volume into 50 mL of NH 4 +-N was the only nitrogen source (concentration of 150 mg / L) in ammonium salt nitrification simulated wastewater for 24 h at 37 °C and 180 r / min. Samples were taken at 0, 12, and 24 h, and after centrifugal filtration, the absorbance was measured at a wavelength of 600 nm using Nessler's reagent spectrophotometry with a full-wavelength microplate reader to determine NH 4 + -N content, and the heterotrophic nitrification performance of the test strain.

[0073] The results of the test are as follows Figure 4 As shown in (a), it can be seen that the C24 strain is in the adaptation stage from 0 to 12 hours and grows slowly. From 12 to 24 hours, the C24 strain grows faster. At the 24th hour, the OD 600 Reach 0.45, for NH 4 + The removal efficiency of -N reached 98%; the average removal rate from 0 to 24 hours was 6.9022 mg / L / h.

[0074] 2. Denitrification performance when nitrate nitrogen is the only nitrogen source

[0075] The Acinetobacter nosocomialis C24 strain obtained in Example 1 was inoculated into an activation medium and then placed in a shaker at 37°C for activation. After it grew to the logarithmic phase, 5% of the activated bacterial solution was inoculated into 50 mL of NO 3 - -N was the only nitrogen source (concentration of 160 mg / L) in nitrate denitrification simulated sewage for 24 h at 37 °C and 180 r / min. After centrifugal filtration, the sample was taken and its absorbance was measured at a wavelength of 600 nm using a full-wavelength microplate reader using the thymol photometric method to determine NO 3 - -N content, and the aerobic denitrification performance of the test strain.

[0076] The results of the test are as follows Figure 4 As shown in (b), it can be seen that the C24 strain is in the adaptation stage from 0 to 12 hours and grows slowly, while the strain grows faster from 12 to 24 hours; the OD of the strain at 24 hours 600 Reach 0.37 to NO 3 - The removal efficiency of -N reached 96%; the average removal rate from 0 to 24 hours was 6.1315 mg / L / h.

[0077] 3. Denitrification performance when nitrite nitrogen is the only nitrogen source

[0078] The Acinetobacter nosocomialis C24 strain obtained in Example 1 was inoculated into an activation medium and then placed in a shaker at 37°C for activation. After it grew to the logarithmic phase, 5% of the activated bacterial solution was inoculated into 50 mL of NO 2 - -N was the only nitrogen source (concentration of 100 mg / L) in simulated wastewater for 24 h at 37 °C and 180 r / min. Samples were taken at 0, 12, and 24 h, and after centrifugal filtration, the absorbance was measured at 600 nm using a full-wavelength microplate reader using N-(1-naphthyl)-ethylenediamine spectrophotometry to determine NO 2 - -N content, and the aerobic denitrification performance of the test strain.

[0079] The results of the test are as follows Figure 4 As shown in (c), it can be seen that the C24 strain grew faster from 0 to 12 hours, and grew slower from 12 to 24 hours. The OD of the C24 strain at 24 hours 600 reached 0.35, and decreased slightly at 48h. 2 - The removal efficiency of -N reached 82%, and the average removal rate over 24 hours was 3.3523 mg / L / h.

[0080] Example 4 Phosphorus removal performance test of strains

[0081] The Acinetobacter nosocomialis C24 strain obtained in Example 1 was inoculated into an activation medium and then placed in a shaker at 37°C for activation. After it grew to the logarithmic phase, 5% of the activated bacterial solution was inoculated into 30 mL of nitrate denitrification simulated sewage with a phosphate concentration of 150 mg / L and cultured for 24 h at 37°C and 180 r / min. After the sample was centrifuged and filtered, the PO was determined by stannous chloride reduction method. 4 3- -P content, test the phosphorus removal performance of the strain. OD 600 The measurement method is to measure its absorbance at a wavelength of 600nm using a full-wavelength microplate reader.

[0082] The results of the test are as follows Figure 4 As shown in (d), the average removal rate of the C24 strain from 0 to 24 h was 0.7596 mg / L / h, and the OD of the strain at 24 h was 600 reached 0.368; at 24h, the C24 strain had a 4 3- The removal efficiency of -P reached 84%.

[0083] Example 5 A wastewater treatment method and its condition optimization

[0084] The C24 strain obtained in Example 1 was used for wastewater treatment, and the aerobic denitrification and denitrification and phosphorus removal performance of the C24 strain was optimized in simulated sewage. The purified C24 strain in Example 1 was first activated and cultured in LB medium for 12 h, then the cells were collected by centrifugation and resuspended in sterile saline under a sterile environment, and the OD was adjusted to 0. 600 The bacterial solution was then inoculated into 200 mL of simulated sewage at a rate of 5% (v / v), and experiments were carried out in simulated sewage of different concentrations: pH 7.4, temperature 37°C, and shaking speed 180 rpm. 3+ / Cu 2+ Ion concentration (0-10 mg / L), carbon source (sucrose, sodium acetate, citric acid, sodium propionate and glucose), C / N ratio (2-10), salinity (0-5°C), initial ammonium nitrogen concentration (50-300 mg / L), P / N ratio (0.1-0.8). After 12 hours, samples were taken and NH was determined according to the methods of Examples 3 and 4. 4 + -N and PO 4 3- -The concentration of P.

[0085] The results of the test are as follows Figure 5 As shown, Fe 3+ / Cu 2+ Ion concentration affects the denitrification effect of the strain. 3+ / Cu 2+ When the ion concentration was 1 mg / L, the removal rate of nitrate nitrogen increased by 59.1%, nitrite nitrogen by 33.62%, ammonium nitrogen by 55.06%, and phosphate by 27.1% ( Figure 5 ac).

[0086] The carbon source affects the denitrification effect of the strain. When the carbon source is sodium acetate, the C24 strain shows the highest NH 4 + -N and PO 4 3- -P removal efficiency, and the highest OD 600 value( Figure 5 d), indicating that the growth and metabolic activity of the strain were best when sodium acetate was used as the carbon source.

[0087] The C / N ratio affects the denitrification effect of the strain. As the C / N ratio increases, NH 4 + -N and PO 4 3-The removal efficiency of -P showed an increasing trend. When the C / N ratio was 10, NH 4 + -N and PO 4 3- -P reached the highest removal efficiency, which were 93.35% and 77.52% ( Figure 5 e).

[0088] Salinity significantly affected the denitrification effect of the strain. When the salinity was 0.5%, NH 4 + -N and PO 4 3- -P had the highest removal efficiency, which were 99.29% and 86.34% ( Figure 5 f).

[0089] Initial NH 4 + -N concentration strain denitrification effect, at the initial NH 4 + When the -N concentration is 100 mg / L, NH 4 + -N had the highest removal efficiency, reaching 99.12%. 4 + With the increase of -N concentration, the removal efficiency decreased, but the PO 4 3- -P removal efficiency remained above 57% ( Figure 5 g).

[0090] The P / N ratio is NH 4 + -N and PO 4 3- -P had little effect on the removal efficiency, but when the P / N ratio was 0.2, NH 4 + -N and PO 4 3- -P had the highest removal efficiency, which were 99.31% and 79.72% ( Figure 5 h).

[0091] In summary, this example systematically investigated the effects of different components of simulated sewage on the nitrogen and phosphorus removal effects of C24 strain, and determined the optimal operating parameters. 4 + -N concentration, the C24 strain can show the best nitrogen and phosphorus removal performance, which provides an important operating parameter reference for the application of the C24 strain in actual sewage treatment.

[0092] Example 6 Application of Acinetobacter spp. C24 in denitrification and phosphorus removal in actual sewage

[0093] The purified Acinetobacter nosocomialis C24 obtained in Example 1 was activated and cultured in LB medium for 24 h, and then the culture was collected by centrifugation. The bacteria were resuspended three times with sterile saline under a sterile environment, and the OD of the resuspended bacteria was adjusted to 600 The bacterial solution was inoculated into municipal sewage from a sewage treatment plant in Guangzhou at a rate of 5% (v / v) and cultured at 30°C and 150rpm. The samples were taken after 0, 24, and 48 hours of treatment to determine NO 2 - -N, NH 4 + -N, NO 3 - N and PO 4 3- -The concentration of P.

[0094] The test results are shown in Table 2 below. The results show that the wastewater treated with the C24 strain has a significant effect on removing nitrate nitrogen, nitrite nitrogen, ammonium nitrogen and phosphate in the water, and can meet the emission standards, providing a new efficient, economical and environmentally friendly way for sewage treatment.

[0095] Table 2 Wastewater treated with strain C24

[0096]

[0097] Comparative Example 1 Comparison of nitrogen and phosphorus removal effects of strains disclosed in the prior art

[0098] At the same time, the performance of different strains disclosed in the prior art in nitrogen and phosphorus removal is summarized in Table 3 below, and compared with the C24 strain provided by the present invention. The statistical results show that the C24 strain provided by the present invention can significantly degrade 150 mg / L nitrate, 100 mg / L nitrite, 150 mg / L ammonium salt and 30 mg / L phosphate within 12 hours, and its nitrogen and phosphorus removal efficiency reaches a high percentage, showing the ability to achieve efficient nitrogen and phosphorus degradation in a relatively short time.

[0099] Table 3 Performance comparison of strains with simultaneous nitrogen and phosphorus removal functions disclosed in the prior art

[0100]

[0101] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A strain of Acinetobacter nosocomialis C24, characterized in that: The strain was deposited in Guangdong Provincial Microbiological Culture Collection Center on November 27, 2024, with the deposit number GDMCC NO: 65597.

2. Use of the strain described in claim 1 or its bacterial solution in removing nitrogen and / or phosphorus from sewage.

3. Use of the strain according to claim 1 or its bacterial solution in the preparation of a product for removing nitrogen and / or phosphorus from sewage.

4. Use of the strain or its bacterial solution according to claim 1 in sewage treatment.

5. Use of the strain described in claim 1 or its bacterial solution in removing ammonia nitrogen, nitrate nitrogen and nitrite nitrogen from sewage.

6. Use of the strain described in claim 1 or its bacterial solution in removing inorganic nitrogen and phosphate pollutants in water.

7. A microbial agent, characterized in that: Containing the strain described in claim 1 or its bacterial solution.

8. A product, characterized in that Containing the bacterial agent according to claim 7.

9. A method for treating sewage, characterized in that: The sewage is treated by using the strain described in claim 1 or its bacterial solution, or the product described in claim 8 is added to the sewage.

10. A method for improving the efficiency of the strain or its bacterial solution in removing nitrogen and / or phosphorus from sewage according to claim 1, characterized in that: When using the strain or its bacterial solution, add 0.5-2 mg / L Fe 3+ / Cu 2+ Ions can promote the heterotrophic nitrification and aerobic denitrification capabilities of C24 strains.

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