A novel heterotrophic nitrification-aerobic denitrification bacterium and its screening method and application in wastewater denitrification

Abstract

The present invention discloses a novel heterotrophic nitrification-aerobic denitrifying bacteria and a screening method thereof and its application in wastewater denitrification. The strain belongs to Acinetobacter sp. and was deposited in the Institute of Microbiology, Guangdong Academy of Sciences on March 2, 2022, named Acinetobacter sp.SCZ-1, and the deposit address is 5th Floor, Building 59, No. 100, Xianlie Middle Road, Guangzhou, China, Postal Code: 510070, and the deposit number is GDMCC NO: 62268. The screening of the strain combines the advantages of continuous aeration method, culture medium selection method, and acid-base indicator method. The strain can also simultaneously carry out heterotrophic nitrification and aerobic denitrification, and has a good application prospect in the denitrification process of actual wastewater.

Description

Technical Field

[0001] The invention relates to the field of environmental microorganisms, and in particular to a novel heterotrophic nitrification-aerobic denitrification bacterium and a screening method thereof, and application thereof in wastewater denitrification. Background Art

[0002] Nowadays, with the serious pollution of lakes and rivers and the improvement of water resource utilization, the discharge standards of effluent pollutants have become more stringent, especially the N index. The effluent of urban sewage treatment plants generally needs to meet the Class A standard. According to the "Comprehensive Discharge Standard of Pollutants for Urban Sewage Treatment Plants" (GB18918-2002), the ammonia nitrogen concentration shall not exceed 5 mg / L and the total nitrogen concentration shall not exceed 15 mg / L. Excessive nitrogen content will make the problem of eutrophication of water bodies increasingly serious, which directly endangers the survival of aquatic plants and animals on the one hand, and indirectly threatens human health on the other hand. Solving this problem is important for purifying water bodies.

[0003] Compared with physical and chemical methods for denitrification, microbial methods have the advantages of low investment, no secondary pollution, long-lasting effect, and simple operation. Traditional biological denitrification processes include nitrification by autotrophic organisms under aerobic conditions and denitrification by heterotrophic organisms under anaerobic conditions. However, the reproduction of autotrophic nitrifying bacteria is relatively slow and the growth cycle is long. At the same time, the aerobic and anaerobic stages must be carried out independently, resulting in a large area of ​​denitrification and high investment costs.

[0004] Heterotrophic nitrification-aerobic denitrification bacteria can achieve simultaneous nitrification and denitrification, thereby simplifying the process and reducing operating costs. Secondly, denitrification can utilize the products of the previous nitrification step, thereby shortening the time of nitrification and denitrification and improving the denitrification efficiency. In addition, the growth rate of heterotrophic nitrification-aerobic denitrification bacteria is significantly faster than that of traditional autotrophic nitrification bacteria, and they have strong adaptability. Therefore, it is important to screen out efficient heterotrophic nitrification-aerobic denitrification strains using appropriate methods for wastewater denitrification. Summary of the invention

[0005] The purpose of the present invention is to provide a novel heterotrophic nitrification-aerobic denitrification bacteria and a screening method thereof and application in wastewater denitrification, wherein a strain with high-efficiency denitrification ability is screened from activated sludge and the strain is applied to simulated wastewater.

[0006] In one aspect of the present invention, the present invention proposes a novel heterotrophic nitrification-aerobic denitrifying bacteria. According to an embodiment of the present invention, the novel heterotrophic nitrification-aerobic denitrifying bacteria belongs to Acinetobacter sp., which was deposited in the Institute of Microbiology, Guangdong Academy of Sciences on March 2, 2022, with a deposit number of GDMCC NO: 62268, and named Acinetobacter sp. SCZ-1. The deposit address is 5th Floor, Building 59, No. 100, Xianlie Middle Road, Guangzhou, China, Postal Code: 510070. The novel heterotrophic nitrification-aerobic denitrifying bacteria of the present invention belong to Gram-negative bacteria, with a milky yellow round colony, a moist and smooth surface, opaque, and rod-shaped cells.

[0007] In addition, the novel heterotrophic nitrification-aerobic denitrification bacteria according to the above embodiment of the present invention may also have the following additional technical features:

[0008] In some embodiments of the present invention, the sequence length of 16S rRNA of the novel heterotrophic nitrification-aerobic denitrification bacteria is 1445 bp, and its sequence information is shown in the sequence table.

[0009] In some embodiments of the present invention, the carbon source for the growth of the novel heterotrophic nitrification-aerobic denitrification bacteria includes sodium succinate or sodium citrate, the carbon-nitrogen ratio is 5-20, the growth temperature is 25-35°C, the rotation speed is 80-220rpm, and the pH is 6.0-9.0.

[0010] In another aspect of the present invention, the present invention proposes a novel method for screening heterotrophic nitrification-aerobic denitrification bacteria. Activated sludge is the main body of the sewage biological treatment system, and the microorganisms in the sludge are the key factors that give the sludge activity, which are mainly bacteria and protozoa. According to the embodiment of the present invention, the continuous aeration method, the culture medium selection method and the acid-base indicator method are mainly combined to screen out a strain of efficient denitrification bacteria, and the strain of the present invention is screened from the return sludge in the Hefei Guozhen Environmental Protection Sewage Treatment Plant. First, the activated sludge collected from the sewage treatment plant is continuously aerated and cultured at 25-35°C for 3-6 months, and nutrient solution is added regularly to make aerobic denitrifying bacteria the dominant population in the system; the acclimated activated sludge is inoculated into the denitrification medium, and cultured in a shaker at 30°C and 150rpm for 3 days, and this is repeated three times; the bacterial solution is then diluted in a gradient manner and spread on the surface of the bromothymol blue solid culture medium, and after constant temperature culture at 30°C for 1-3 days, the strains with blue halos are selected and further purified on the denitrification medium; finally, the nitrification and denitrification performance of the purified strains is tested, and the strains with the best performance are stored in a -80°C refrigerator.

[0011] In another aspect of the present invention, a method for denitrifying nitrogen-containing water is provided. According to an embodiment of the present invention, the novel heterotrophic nitrification-aerobic denitrification bacteria are used.

[0012] In addition, the method for denitrification of nitrogen-containing water according to the above embodiment of the present invention may also have the following additional technical features:

[0013] In some embodiments of the present invention, nitrogen-containing substances include but are not limited to ammonium nitrogen, nitrate nitrogen, and nitrite nitrogen.

[0014] In some embodiments of the present invention, a carbon source is added to the nitrogen-containing water body, wherein the carbon source is sodium succinate or sodium citrate, and the C / N ratio is 8 to 20, and the pH of the nitrogen-containing water body is adjusted to 6.0 to 9.0.

[0015] In some embodiments of the present invention, when the nitrogen source of the nitrogen-containing water body is ammonium nitrogen with a concentration of 50 to 250 mg / L, the novel heterotrophic nitrification-aerobic denitrifying bacteria is inoculated into the water body according to 0.8% to 1.2% of the total volume of the nitrogen-containing water body, and cultured at 25 to 35° C. and 100 to 200 rpm for 48 to 70 hours, thereby reducing the concentration of ammonium nitrogen.

[0016] In some embodiments of the present invention, when the nitrogen source of the nitrogen-containing water body is nitrate nitrogen with a concentration of 50 to 250 mg / L, the novel heterotrophic nitrification-aerobic denitrifying bacteria is inoculated into the water body according to 0.8% to 1.2% of the total volume of the nitrogen-containing water body, and cultured at 25 to 35° C. and 100 to 200 rpm for 48 to 70 hours, thereby reducing the concentration of nitrate nitrogen.

[0017] In some embodiments of the present invention, when the nitrogen source of the nitrogen-containing water body includes ammonium nitrogen and nitrate nitrogen, and the concentration of ammonium nitrogen and nitrate nitrogen is between 20 and 150 mg / L, the novel heterotrophic nitrification-aerobic denitrifying bacteria is inoculated into the water body according to 0.8% to 1.2% of the total volume of the nitrogen-containing water body, and cultured at 25 to 35° C. and 100 to 200 rpm for 48 to 70 hours, thereby reducing the concentration of ammonium nitrogen and nitrate nitrogen.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The strain of the present invention can be applied to any wastewater with excessive nitrogen content. When the concentration of ammonium nitrogen or nitrate nitrogen is 100 mg / L, the strain has a good removal effect on ammonium nitrogen and nitrate nitrogen respectively, and can remove more than 99% of ammonium nitrogen and more than 97% of nitrate nitrogen respectively within 24 hours, and there is no accumulation of nitrite nitrogen. When the concentrations of ammonium nitrogen and nitrate nitrogen are 50 mg / L respectively, ammonium nitrogen and nitrate nitrogen can also be removed synchronously and efficiently. This has important practical significance for developing efficient denitrification microbial agents and applying them to sewage treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a morphological characteristic diagram of the novel heterotrophic nitrification-aerobic denitrification bacteria after streaking in Example 2 of the present invention;

[0021] Figure 2 This is a scanning electron microscope (SEM) image of the novel heterotrophic nitrification-aerobic denitrification bacteria in Example 2 of the present invention;

[0022] Figure 3 This is an agarose gel electrophoresis diagram of the 16S rRNA gene amplification product of the novel heterotrophic nitrification-aerobic denitrification bacteria in Example 2 of the present invention;

[0023] Figure 4 This is a phylogenetic evolutionary tree of the novel heterotrophic nitrification-aerobic denitrification bacteria in Example 2 of the present invention, showing that the strain with the closest relationship thereto is Acinetobacter sp.Ue2-1.1;

[0024] Figure 5 Schematic diagram of the denitrification performance of the novel heterotrophic nitrification-aerobic denitrifying bacteria in Example 3 of the present invention when ammonium nitrogen is used as the only nitrogen source;

[0025] Figure 6 Schematic diagram of the denitrification performance of the novel heterotrophic nitrification-aerobic denitrification bacteria in Example 4 of the present invention when nitrate nitrogen is used as the only nitrogen source, and a growth curve diagram of the strain;

[0026] Figure 7 Schematic diagram of the denitrification performance of the novel heterotrophic nitrification-aerobic denitrifying bacteria in Example 5 of the present invention when ammonium nitrogen and nitrate nitrogen are used as a mixed nitrogen source. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] The embodiment of the present invention provides a method for screening heterotrophic nitrification-aerobic denitrification bacteria, which combines continuous aeration method, selective culture medium method and acid-base indicator method to screen out efficient denitrification strains. The screened strains can simultaneously carry out nitrification and denitrification processes, thereby achieving the effect of efficiently reducing the nitrogen content in sewage.

[0029] Example 1: Screening of heterotrophic nitrification-aerobic denitrification strain Acinetobacter sp. SCZ-1.

[0030] (1) Sample source: Activated sludge from the recirculation tank of Hefei Guozhen Environmental Protection Wastewater Treatment Plant.

[0031] (2) Enrichment and domestication of activated sludge by continuous aeration: The activated sludge collected from the Guozhen Environmental Protection Wastewater Treatment Plant is placed in a 150L barrel for continuous aeration for 3 to 6 months (25 to 35°C), with an aeration volume of 80L / min. The aeration device is an ACO series electromagnetic air pump (ACO-002, 35W, 220VAC / 50Hz). Under continuous aeration, the color and state of the activated sludge are regularly observed to ensure that the color of the activated sludge is brown and not black; at the same time, its pH value is regularly tested to keep it growing in a neutral to alkaline environment. In addition, the nutrient solution is added to the domesticated activated sludge once a week. The composition of the nutrient solution is as follows:

[0032] Sucrose 40g / L, NH4Cl 8.6g / L, KH2PO4 2g / L, CaCl2 1.2g / L, MgSO4 1.6g / L, NaHCO3 4g / L, trace elements I 0.7mL / L, trace elements II 0.7mL / L.

[0033] Trace elements I: EDTA 5000mg / L, FeSO4 5000mg / L,

[0034] Trace elements II: EDTA 15000mg / L, ZnSO4·7H2O 430mg / L, CoCl2·6H2O 240mg / L, MnCl2·4H2O 990mg / L, CuSO4·5H2O 250mg / L, Na2MoO4·2H2O 220mg / L, NiCl2·6H2O 190mg / L, H3BO4 14mg / L.

[0035] (3) Enrichment culture of strains: Take 10 mL of domesticated activated sludge and inoculate it into 90 mL of sterilized enrichment culture medium for 3 days (25-35°C), then take 10% (v / v) of the supernatant and transfer it to new enrichment culture medium for domestication. Repeat this step three times.

[0036] (4) Primary screening of strains based on the acid-base indicator method: Take 1 mL of the domesticated bacterial solution and dilute it in a 10-fold gradient (10 -1 ~10 -8 ). Take 0.1mL of diluted bacterial solution (the dilution concentration is 10 -5 ~10 -8, 3 groups of parallels are set for each concentration) are spread on the surface of BTB (bromothymol blue) solid culture medium, and the plate is inverted in a 30℃ constant temperature incubator for culture. When a single colony with a blue halo grows on the plate, the bacteria are picked and cultured in a new DM enriched medium overnight. The bacterial suspension is streaked on the DM solid culture medium, and a single colony is picked and cultured in the DM liquid culture medium until the logarithmic growth phase, and then stored in a -80℃ ultra-low temperature refrigerator.

[0037] (5) Rescreening of strains based on culture medium selection method: The strains stored in the refrigerator were inoculated into LB liquid culture medium, and then the activated strains were inoculated into denitrification culture medium and nitrification culture medium for 48 hours. The contents of ammonium nitrogen, nitrate nitrogen and other nitrogen in this process were measured respectively, and their heterotrophic nitrification and denitrification performances were evaluated accordingly. Strains with high denitrification ability were selected and stored in 15% (v / v) glycerol and frozen in a -80°C refrigerator to obtain new heterotrophic nitrification-aerobic denitrification bacteria. At the same time, the OD of the strains was also measured. 600 .

[0038] The novel heterotrophic nitrification-aerobic denitrification bacteria belongs to Acinetobacter sp., which was deposited in the Institute of Microbiology, Guangdong Academy of Sciences on March 2, 2022, with a deposit number of GDMCC NO: 62268, and named Acinetobacter sp. SCZ-1. The deposit address is 5th Floor, Building 59, No. 100, Xianlie Middle Road, Guangzhou, China, Postal Code: 510070. The novel heterotrophic nitrification-aerobic denitrification bacteria of the present invention belong to Gram-negative bacteria, with a creamy yellow round colony, a moist and smooth surface, opaque, and rod-shaped cells.

[0039] In addition, the novel heterotrophic nitrification-aerobic denitrification bacteria according to the above embodiment of the present invention may also have the following additional technical features:

[0040] In some embodiments of the present invention, the sequence length of 16S rRNA of the novel heterotrophic nitrification-aerobic denitrification bacteria is 1445 bp, and its sequence information is as follows:

[0041]

[0042] (6) The culture medium used in the above steps is as follows:

[0043] Bromothymol blue medium (BTB medium): KNO3 1.0g / L, KH2PO4 1.0g / L, FeCl2·6H2O0.5g / L, CaCl2 0.2g / L, MgSO4·7H2O 1.0g / L, C4H4Na2O4 8.5g / L, bromothymol blue 1mL / L, pH 6-7.5.

[0044] Enrichment culture medium: Na2HPO4·12H2O 7.9g / L, C4H4Na2O4 4.7g / L, KH2PO4 1.5g / L, MgSO4·7H2O0.1g / L, KNO3 1.0g / L, trace elements 2mL / L, pH 6-7.5.

[0045] Denitrification medium (DM medium): Na2HPO4·12H2O 7.9g / L, C4H4Na2O4 4.7g / L, KH2PO41.5g / L, MgSO4·7H2O 0.1g / L, KNO3 0.72g / L, trace elements 2mL / L, pH 6-7.5.

[0046] Nitration medium (BM medium): (NH4)2SO4 0.47g / L, KH2PO4 1.5g / L, C4H4Na2O4 4.7g / L, MgSO4·7H2O 0.1g / L, Na2HPO4·12H2O 7.9g / L, trace elements 2mL / L, pH 6-7.5.

[0047] LB medium: tryptone 10 g / L, NaCl 10 g / L, yeast extract 5 g / L.

[0048] Trace elements: EDTA 50g / L, CaCl2 5.5g / L, FeSO4·7H2O 5.0g / L, CuSO4·5H2O 1.6g / L, ZnSO4 2.2g / L, MnCl2·4H2O 5.1g / L, ammonium molybdate 1.1g / L, CoCl2·6H2O 1.6g / L, adjust pH to neutral.

[0049] All of the above are liquid culture media. If you prepare corresponding solid culture media, you need to add 1.5% agar to the liquid culture media.

[0050] Unless otherwise stated, all liquid culture media are placed in 250 mL conical flasks. 100 mL of liquid culture medium is added to each conical flask. After preparation, the flasks are sealed with sealing film and sterilized at 121°C for 30 minutes.

[0051] Example 2: Morphological characteristics and molecular biological identification of the strain

[0052] like Figure 1 and Figure 2 As shown, when the strain is cultured on DM medium for 1 to 2 days, its colony morphology is characterized by: milky yellow, regular edges, round, slightly convex, opaque, and smooth surface. The morphology of the strain is rod-shaped when observed by scanning electron microscopy.

[0053] The purified bacterial solution was used as a template for PCR amplification, and the universal primer pair 27F / 1492R was selected (the upstream primer was 27F: 5'-AGAGTTTGATCCTGGCTCAG-3', and the downstream primer was 1492R: 5-TACGGCTACCTTGTACGACTT-3'). The reaction conditions for PCR amplification were pre-denaturation at 98°C for 10 min, denaturation at 98°C for 10 s, renaturation at 55°C for 15 s, and extension at 72°C for 90 s. The cycle was repeated 31 times starting from the second step, and then extended at 72°C for 5 to 10 min, and finally stored at 4°C for 15 min.

[0054] The PCR amplification products were subjected to agarose gel electrophoresis. The results of agarose gel electrophoresis showed that the amplification product band at about 1500 bp was brighter and there were no other mixed bands, such as Figure 3 shown.

[0055] The PCR amplified product was sent to Anhui General Biological Co., Ltd. for sequence sequencing. The sequencing results are shown in the sequence table. The obtained sequence was submitted to the NCBI website and compared with the existing strain data in the GenBank database. Then, the BLAST ( http: / / www.ncbi.nlm.nih.gov / blast / ) to search for strains with higher similarity, wherein the homology between the strain and Acinetobacter sp.Ue2-1.1 is as high as 98%. Figure 4 As shown, MEGA6.0 software was used to construct a phylogenetic tree using the Neighbor-Joining method to further analyze the genus and species of the strains.

[0056] Example 3: Test of nitrification performance of the strain

[0057] A carbon source was added to the simulated wastewater, wherein the carbon source was sodium succinate or sodium citrate, and the C / N ratio was 8-20, and the pH of the nitrogen-containing water was adjusted to 6.0-9.0. The strain stored in the -80°C refrigerator in Example 1 was inoculated into LB liquid culture medium, and then placed in a shaking incubator at 30°C for activation. The activated bacterial liquid was inoculated into 100 mL of NH4 by volume at 1% + -N was the only nitrogen source (concentration of 100 mg / L) in simulated wastewater for 60 h, and samples were taken at 0, 6, 12, 24, 30, 36, 48, and 60 h, respectively. After centrifugation and filtration, the heterotrophic nitrification performance of the strain was tested. The simulated wastewater formula was consistent with the nitrification medium (BM medium) described in Example 1. At the same time, the product NO3 that may appear during the degradation process was also detected. - -N and NO2 - -N content. Among them, NH4 + -N content is measured by Nessler's reagent spectrophotometry, testing NO3 - -N and NO2 - The method used for -N content is UV spectrophotometer method.

[0058] like Figure 5 As shown, at 24h, the strain was sensitive to NH4 + -N removal efficiency reached 99%, and NH4 + The removal efficiency of -N reached 99.85%. The removal rate of ammonium nitrogen reached a maximum of 6.43 mg / L / h in 6-12 hours, and the average removal rate in 0-24 hours was 4.05 mg / L / h.

[0059] When (NH4)2SO4 is used as the sole nitrogen source in the culture medium, the strain can effectively reduce the concentration of ammonium nitrogen, and there is basically no accumulation of nitrate nitrogen and nitrite nitrogen.

[0060] Example 4: Denitrification performance test of the strain

[0061] A carbon source was added to the simulated wastewater, wherein the carbon source was sodium succinate or sodium citrate, and the C / N ratio was 8-20, and the pH of the nitrogen-containing water was adjusted to 6.0-9.0. The strain stored in the -80°C refrigerator in Example 1 was activated in LB liquid culture medium, and then the activated bacterial liquid was inoculated into 100 mL of NO3 by 1% by volume. - -N was the only nitrogen source (concentration of 100 mg / L) in simulated wastewater for 60 h. Samples were taken at 0, 6, 12, 24, 30, 36, 48, and 60 h, centrifuged and filtered with a 0.22 μm filter, and the NO3 content of the supernatant was measured. - -N, NO2 - -N concentration and OD600 The simulated wastewater formulation is consistent with the denitrification medium (DM medium) formulation described in Example 1. Test NO3 - -N and NO2 - -N content was measured by UV spectrophotometry using OD 600 It was measured with an ultraviolet spectrophotometer at a wavelength of 600 nm.

[0062] like Figure 6 As shown, the strain was in the adaptation stage from 0 to 6 hours and grew slowly, while the strain grew faster from 6 to 24 hours. The OD of the strain at 24 hours was 600 Reached 1.56, and was in a plateau after 24 hours. 600 The value remained stable and then decreased.

[0063] At 24 h, the strain was sensitive to NO3 - The removal rate of -N reached 97.47%, and the removal rate after 60 hours reached 99.7%. The removal rate after 6 to 12 hours reached a maximum of 6.25 mg / L / h, and the average removal rate after 0 to 24 hours was 4.28 mg / L / h.

[0064] In addition, the strain is effective in removing NO3 - -N process does not produce NO2 - -N accumulation, indicating that NO3 - -N can be quickly converted into gas, thus achieving efficient denitrification.

[0065] Example 5: Test on the performance of simultaneous nitrification and denitrification of the strain

[0066] A carbon source was added to the simulated wastewater, wherein the carbon source was sodium succinate or sodium citrate, and the C / N ratio was 8-20, and the pH of the nitrogen-containing water was adjusted to 6.0-9.0. The strain stored in the -80°C refrigerator in Example 1 was inoculated into LB liquid culture medium for activation, and then the activated strain was inoculated into 100 mL of NO3 containing 1% of the total volume of the simulated wastewater. - -N and NH4 + -N two mixed nitrogen source simulated wastewater, cultured at 30℃ in a shaker at 150rpm for 60h, of which NO3 - -N concentration is 50mg / L, NH4 + The concentration of -N was 50 mg / L. Samples were taken at 0, 6, 12, 24, 30, 36, 48, and 60 h, respectively. The samples were centrifuged and filtered with a 0.22 μm filter membrane, and the NH4 in the supernatant was measured. + -N, NO3 - -N and NO2 - -N concentration. Among them, NH4+ -N content is measured by Nessler's reagent spectrophotometry, testing NO3 - -N and NO2 - The method used for -N content is UV spectrophotometer method.

[0067] The culture medium formula of mixed nitrogen source is: KNO3 0.36g / L, (NH4)2SO4 0.24g / L, KH2PO4 1.5g / L, C4H4Na2O4 4.7g / L, MgSO4·7H2O 0.1g / L, Na2HPO4·12H2O 7.9g / L, trace elements 2mL / L, and the pH is adjusted to 6-7.5.

[0068] like Figure 7 As shown, at 12h, NH4 + -N removal rate reached 98.26%, and the removal rate of NO3 - -N removal rate reached 98.56%, and the removal rate of NH4 + -N removal rate was 99.56%, and the removal rate of NO3 - -N removal rate was 99.46%. 0~6h The strain was effective for NH4 + The maximum removal rate of -N is 5.28 mg / L / h, and the removal rate of NH4 + The average removal rate of -N was 4.14 mg / L / h. - The average removal rate of -N was 2.06 mg / L / h.

[0069] In a culture medium containing ammonium nitrogen and nitrate nitrogen as mixed nitrogen sources, the strain can simultaneously reduce the concentrations of these two nitrogen sources, and NO2 - -N No obvious accumulation.

[0070] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A novel heterotrophic nitrification-aerobic denitrification bacteria, characterized by: The novel heterotrophic nitrification-aerobic denitrification bacteria were deposited in the Institute of Microbiology, Guangdong Academy of Sciences on March 2, 2022, with the deposit number GDMCC NO: 62268 and named Acinetobacter sp . SCZ-1.

2. A novel heterotrophic nitrification-aerobic denitrifying bacteria according to claim 1, characterized in that: The sequence length of 16S rRNA of the novel heterotrophic nitrification-aerobic denitrification bacteria is 1445 bp, and its sequence information is shown in the sequence table.

3. A novel heterotrophic nitrification-aerobic denitrifying bacteria according to claim 1, characterized in that: The carbon source for the growth of the novel heterotrophic nitrification-aerobic denitrification bacteria includes sodium succinate or sodium citrate, the carbon-nitrogen ratio is 5-20, the growth temperature is 25-35°C, the rotation speed is 80-220 rpm, and the pH is 6.0-9.

0.

4. A method for denitrification of nitrogen-containing water, characterized in that: The novel heterotrophic nitrification-aerobic denitrifying bacteria according to any one of claims 1 to 3 is used, wherein the nitrogen source of the nitrogen-containing water body is ammonium nitrogen and / or nitrate nitrogen.

5. A method for denitrifying nitrogen-containing water according to claim 4, characterized in that: A carbon source is added to the nitrogen-containing water body, wherein the carbon source is sodium succinate or sodium citrate, and the C / N ratio is 8-20, and the pH value of the nitrogen-containing water body is adjusted to 6.0-9.

0.

6. A method for denitrifying nitrogen-containing water according to claim 5, characterized in that: When the nitrogen source of the nitrogen-containing water body is ammonium nitrogen with a concentration of 50-250 mg / L, the novel heterotrophic nitrification-aerobic denitrifying bacteria is inoculated into the water body according to 0.8%-1.2% of the total volume of the nitrogen-containing water body, and cultured at 25-35° C. and 100-200 rpm for 48-70 h, thereby reducing the concentration of ammonium nitrogen.

7. The method for denitrifying nitrogen-containing water according to claim 5, characterized in that: When the nitrogen source of the nitrogen-containing water body is nitrate nitrogen with a concentration of 50-250 mg / L, the novel heterotrophic nitrification-aerobic denitrifying bacteria is inoculated into the water body according to 0.8%-1.2% of the total volume of the nitrogen-containing water body, and cultured at 25-35° C. and 100-200 rpm for 48-70 h, thereby reducing the concentration of nitrate nitrogen.

8. The method for denitrifying nitrogen-containing water according to claim 5, characterized in that: When the nitrogen source of the nitrogen-containing water body includes ammonium nitrogen and nitrate nitrogen, and the concentration of ammonium nitrogen and nitrate nitrogen is between 20 and 150 mg / L, the novel heterotrophic nitrification-aerobic denitrifying bacteria is inoculated into the water body according to 0.8% to 1.2% of the total volume of the nitrogen-containing water body, and cultured at 25 to 35° C. and 100 to 200 rpm for 48 to 70 hours, thereby reducing the concentration of ammonium nitrogen and nitrate nitrogen.

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