A strain of Hydizia hydizia YB079 and its application in biological denitrification

Abstract

The present invention provides a strain of Hydizia hydizia YB079, which is separated from the activated sludge of the denitrification system of nitrogen-containing wastewater and has good biological denitrification ability. Strain YB079 has the strongest ammonia nitrogen removal ability under aerobic conditions; it can effectively remove nitrate nitrogen and nitrite nitrogen under anaerobic, aerobic and static culture conditions. The removal rate of ammonia nitrogen with an initial concentration of 600 mg / L can reach 57.99% within 120 hours; the nitrite nitrogen with an initial concentration of 600 mg / L can be completely removed; the nitrate nitrogen with an initial concentration of 325 mg / L can be removed at a rate of 78.28%. The removal rates of ammonia nitrogen with an initial concentration of 110 mg / L, nitrate nitrogen with an initial concentration of 65 mg / L, and nitrite nitrogen with an initial concentration of 170 mg / L in nitrogen-contaminated sludge can reach 81.24%, 92.77%, and 91.78% within 114 hours. Within 114 hours, it can remove 270mg / L ammonia nitrogen, 190mg / L nitrate nitrogen and 390mg / L nitrite nitrogen in nitrogen-contaminated kitchen filtrate at the rates of 100%, 98.51% and 100% respectively.

Description

Technical Field

[0001] The present invention relates to a strain of Hydizia hydizia YB079 ( Dietzia maris YB079) and its application in biological denitrification treatment of nitrogen-containing wastewater, belonging to the field of environmental microbial technology. Background Art

[0002] With the rapid development of society, the discharge of nitrogen-containing wastewater in industry, agriculture, and life has gradually increased, resulting in the artificial delivery of too many nutrients, which has produced a series of adverse effects and destroyed the diversity of the ecosystem. For example, excessive nitrogen content in water will cause eutrophication of water bodies. Drinking water with high nitrogen content is also prone to mutagenesis, carcinogenesis, and teratogenesis. Nowadays, the sources of nitrogen-containing wastewater have become more extensive, and the discharge has become more and more, which has a great impact on the ecological environment and poses a serious threat to the ecosystem. The nitrogen in water bodies is mainly in the form of ammonia nitrogen (NH 4 + -N), nitrate nitrogen (NO 3 - -N), nitrite nitrogen (NO 2 - -N), organic nitrogen and other four different forms. Various forms of nitrogen in nature can be transformed into each other under the influence of microorganisms. Therefore, microbial denitrification and water environment restoration has become a hot research area.

[0003] In the development and utilization of denitrification technology, the denitrification technologies currently used for nitrogen-containing wastewater can be mainly divided into physical and chemical methods and biological methods. Although the physical and chemical method has a high denitrification efficiency, the operating cost is also high and the products after the chemical reaction may cause secondary pollution. Therefore, biological denitrification technology will have greater application prospects. Continuously acquiring efficient biological denitrification strains and developing supporting denitrification processes have become key factors in further improving the efficiency of biological denitrification of wastewater. In particular, for ammonia nitrogen wastewater, finding a strain that can simultaneously have the ability to oxidize and denitrify ammonia has an important contribution to improving the removal efficiency of ammonia nitrogen in wastewater. Summary of the invention

[0004] The present invention provides a strain of Heidiella sp. YB079 ( Dietzia maris YB079), and its application in biological denitrification of nitrogen-containing wastewater.

[0005] A strain of Hydizia hydizia YB079 was deposited in the China Center for Type Culture Collection in August 2022, with the deposit address being Wuhan University, Wuhan, China, with the deposit number being CCTCC M 20221251. Dietzia maris YB079, deposit date: August 8, 2022.

[0006] The 16S rDNA sequencing result of the YB079 strain is shown in SEQ ID NO.1.

[0007] The culture method of the strain YB079 is:

[0008] (1) Activation of the preserved strain. The strain can be cultured in LB medium. Use a sterile bamboo stick to pick up a small amount of strain ice residue from the YB079 strain preserved at -80℃, place it on a culture plate containing LB solid medium, and use a sterile bamboo stick to draw lines. Place the culture plate with the inoculation line upside down in a 28℃ biochemical incubator and culture for 27-36 hours to grow YB079 colonies. The colonies are orange-red, round and opaque, smooth, and have neat edges.

[0009] (2) Strain expansion culture. The strain was expanded and cultured in DM medium. The medium composition (1L volume): KNO 3 1g (or NH 4 Cl 1.2g, or NaNO 2 1.5g); sodium succinate 16.88g; Na 2 HPO 4 12H 2 O 10.55g; KH 2 PO 4 1.5 g; MgSO 4 7H 2 O 0.1g; trace elements 2.0 mL; pH 7.2-7.5, distilled water to 1L. Trace elements (1L volume): Na 2 EDTA 50g, CaCl 2 5.5 g, MnCl 2 ·4H 2 O 5.06 g, FeSO 4 5g, ZnSO 4 7H 2 O 2.2g, CuSO 4 ·5H 2 O1.57g, CoCl 2 6H 2 O 1.6g, distilled water 1L. The culture temperature is 28℃, and it can be cultured under aerobic conditions, static conditions, and anaerobic conditions.

[0010] The strain is used for biological denitrification in nitrogen-containing wastewater.

[0011] As a practical solution, the strain is used for biological denitrification in leachate of food waste or polluted pond sludge.

[0012] The strain is used to remove one or more of ammonia nitrogen, nitrate nitrogen and nitrite nitrogen in nitrogen-containing wastewater.

[0013] The strain is used in nitrogen-containing wastewater by oxidizing ammonia nitrogen, reducing nitrate nitrogen, or reducing nitrite nitrogen.

[0014] The nitrogen-containing wastewater removal process is carried out in an aerobic or air static environment; or one or both of nitrate nitrogen and nitrite nitrogen are removed in an anaerobic environment.

[0015] The aerobic condition is shaking (200 r / min) in a constant temperature shaker, which is used for the strain YB079 to oxidize ammonia.

[0016] The static condition is static culture in the air, which is used for strain YB079 to reduce nitrate or nitrite.

[0017] The anaerobic condition is as follows: the inoculated bacterial liquid is placed in an anaerobic culture tank, sealed and cultured after deoxygenation, and is used for the strain YB079 to reduce nitrate or nitrite.

[0018] Surprisingly, it was found that the strain YB079 had the strongest ability to remove ammonia nitrogen under aerobic conditions; under anaerobic conditions, the strain could not remove ammonia nitrogen; but under static culture, it had the ability to remove ammonia nitrogen.

[0019] In fact, the strain YB079 can effectively remove nitrite nitrogen under anaerobic, aerobic and static culture conditions.

[0020] Incredibly, the strain YB079 can effectively remove nitrate nitrogen under anaerobic, aerobic and static conditions.

[0021] The present invention also provides a biological denitrification agent, which comprises the bacterial strain Hydizia hydizia YB079, which is classified and named Dietzia maris YB079, deposited in the China Center for Type Culture Collection, the deposit address is Wuhan University, Wuhan, China, the deposit number is CCTCC NO: M 20221251, the deposit date is August 8, 2022.

[0022] The biological denitrification agent is used for biological denitrification in nitrogen-containing sewage, and the nitrogen-containing sewage includes leachate from kitchen waste or polluted pond sludge.

[0023] The strain is used to remove one or more of ammonia nitrogen, nitrate nitrogen and nitrite nitrogen in nitrogen-containing wastewater. The nitrogen-containing wastewater removal process is carried out in an aerobic or air static environment; or one or both of nitrate nitrogen and nitrite nitrogen are removed in an anaerobic environment.

[0024] The aerobic condition is shaking (200 r / min) in a constant temperature shaker, which is used for the strain YB079 to oxidize ammonia.

[0025] The static condition is static culture in the air, which is used for strain YB079 to reduce nitrate or nitrite.

[0026] The anaerobic condition is as follows: the inoculated bacterial liquid is placed in an anaerobic culture tank, sealed and cultured after deoxygenation, and is used for the strain YB079 to reduce nitrate or nitrite.

[0027] The strain YB079 is used for biological denitrification of water samples.

[0028] Similarly, the strain YB079 has the strongest ability to remove ammonia nitrogen under aerobic conditions; under anaerobic conditions, the strain cannot remove ammonia nitrogen; and under static culture conditions, it has the ability to remove ammonia nitrogen.

[0029] At the same time, the strain YB079 can effectively remove nitrite nitrogen under anaerobic, aerobic and static culture conditions.

[0030] Incredibly, the strain YB079 can effectively remove nitrate nitrogen under anaerobic, aerobic and static conditions.

[0031] The strain YB079 is used for biological denitrification in leachate of kitchen waste.

[0032] The strain YB079 was directly inoculated into nitrogen-contaminated kitchen waste leachate for biological denitrification, with an inoculation amount of 0.4-0.6 OD / 25mL of leachate. When the initial ammonia nitrogen concentration of the leachate was 270mg / L, all ammonia nitrogen was removed within 114 hours. When the initial nitrate nitrogen concentration was 190mg / L, the removal rate within 114 hours was 98.51%. When the initial nitrite nitrogen concentration was 390mg / L, all nitrite nitrogen was removed within 114 hours. The OD value of the strain also increased from 0.832 to 5.78 within 114 hours.

[0033] Application of the strain YB079 in biological denitrification in polluted pond sludge. The strain YB079 is directly inoculated into nitrogen-contaminated pond sludge for biological denitrification, and the inoculation amount is 0.4-0.6 OD / 25g polluted pond sludge. When the initial ammonia nitrogen concentration in the sludge is 110 mg / L, the removal rate of ammonia nitrogen is 81.24% within 114 hours. When the initial nitrate nitrogen concentration is 65 mg / L, the removal rate of nitrate nitrogen is 92.77% within 114 hours. When the initial nitrite nitrogen concentration is 170 mg / L, the removal rate of nitrite nitrogen is 91.78% within 114 hours. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Strain morphology of YB079.

[0035] Figure 2 Scanning electron micrograph of YB079.

[0036] Figure 3 Phylogenetic tree of YB079 strain based on 16S rDNA.

[0037] Figure 4 Growth of YB079 under different oxygen conditions.

[0038] Figure 5 Ammonia nitrogen degradation ability (A) and strain growth (B) of YB079 under different oxygen conditions.

[0039] Figure 6 The nitrite-nitrogen degradation ability (A) and strain growth (B) of YB079 under different oxygen conditions.

[0040] Figure 7 The nitrate degradation ability (A) and strain growth (B) of YB079 under different oxygen conditions.

[0041] Figure 8 Ammonia nitrogen degradation ability of YB079 under different ammonia nitrogen concentrations.

[0042] Fig. 9 Nitrite degradation ability of YB079 at different nitrite concentrations.

[0043] Fig.10 Nitrate-nitrogen degradation ability of YB079 at different nitrate-nitrogen concentrations.

[0044] Fig.11 Nitrogen degradation of YB079 in food waste leachate (A) and strain growth (B).

[0045] Fig.12 Nitrogen degradation of YB079 in pond sludge. DETAILED DESCRIPTION

[0046] The present invention is described in detail below in conjunction with specific embodiments. However, those skilled in the art will appreciate that the following embodiments are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention.

[0047] Example 1

[0048] Isolation and identification of strain YB079

[0049] Take 500 ml of activated sludge from the denitrification treatment of nitrogen-containing wastewater in this laboratory (Bioengineering Laboratory of Three Gorges University), add 3.5 L of enrichment medium (the formula of enrichment medium is: NH 4 Cl 1.2g, NaNO 2 1.5 g, NaHCO 3 0.5 g, KHCO 3 0.5 g, MgSO 4 7H 2 O 0.2g, CaCl 2 ·2H 2 O 0.136g, KH 2 PO 4 0.027g, trace element 1 1mL, trace element 2 1.25mL, tap water 1L. Trace element 1: EDTA 1.25g, FeSO 4 1.25g, distilled water 250mL. Trace elements 2: EDTA 1.25g, ZnSO4·7H2O 0.1075g, CoCl 2 6H 2 O 0.06g, MnCl 2 ·4H 2 O 0.2475g,CuSO 4 ·5H 2 O 0.0625g, NaMoO 4 ·2H 2 O 0.055g, NiCl 2 6H 2 O 0.0475g, H3 B O 3 0.0035g, distilled water 250mL. ), all the above substances are placed in a 5L culture tank of the fully automatic fermentation control system for enrichment culture, the temperature is set to 28°C, the rotation speed is 50rpm, the pH is maintained between 7.0-8.0, and whenever the pH value is lower than 7.0, NaOH solution is used to adjust the pH to above 7.0. Take out 1L of fermentation liquid every 2 days, and inject 1L of fresh enrichment culture liquid at the same time. At the same time, detect the concentrations of ammonia nitrogen, nitrate nitrogen, and nitrite nitrogen in the feed liquid and the culture liquid after feeding to obtain the removal efficiency of the enrichment culture for ammonia nitrogen, nitrate nitrogen, and nitrite nitrogen. When the removal efficiency of the enrichment culture for ammonia nitrogen, nitrate nitrogen, and nitrite nitrogen is stable, take out the enrichment culture and dilute the enrichment culture to 10 with sterile water. -2 , 10 -3 , 10 -4 For each of the three gradients, 200 μL of the suspension was spread on a sterilized solid medium containing nitrifying bacteria (the formula of the nitrifying medium is: NH 4 Cl 0.5 g; C 4 H4 Na 2 O 4 3.0 g; MgSO 4 7H 2 O 3.0 g; K 2 HPO 4 4.8 g; NaCl 2.0 g; MnSO 4 ·4H 2 O 0.05g; FeSO 4 0.05g; agar 20g; distilled water 1L), cultured in a 28℃ incubator, 13 strains with different morphologies were selected as candidate bacteria, streaked on nitrifying bacteria solid culture plates for purification and culture, each strain was isolated and purified 3-5 times to obtain pure culture of each strain.

[0050] Strain preservation: The glycerol tube method is used for strain preservation, and two copies of each pure strain are preserved. The purified strain is inoculated into LB liquid culture medium and cultured in a 28°C constant temperature incubator until the bacterial solution OD600 is greater than 1.0, which is used as the bacterial solution to be preserved; 60% glycerol and 1.5ml Eppendorf tubes are sterilized in advance, and then glycerol and the above bacterial solution are added to the tube in a ratio of 1:2, mixed, sealed, marked, and stored in an ice tray in a -80°C refrigerator. The LB culture medium formula is: 10.0g tryptone, 5.0g yeast extract powder, 10.0g NaCl, pH 7.2-7.5, and 1L distilled water.

[0051] The strains screened above were cultured in DM medium with ammonium chloride, potassium nitrate and sodium nitrite as nitrogen sources, respectively, and the removal rates of ammonia nitrogen, nitrate nitrogen and nitrite nitrogen were used as indicators for screening, and strains with higher removal rates of ammonia nitrogen, nitrate nitrogen and nitrite nitrogen were selected as the strains of the present invention. The formula of ammonia nitrogen DM medium is: NH 4 Cl 1.2g; sodium succinate 16.88g; Na 2 HPO 4 12H 2 O 10.55g; KH 2 PO 4 1.5 g; MgSO 4 7H 2 O 0.1g; trace elements 2.0 mL; pH 7.2-7.5, distilled water 1L. Trace elements: Na 2 EDTA 50g, CaCl 2 5.5 g, MnCl 2 ·4H 2 O 5.06 g, FeSO 4 5g, ZnSO 47H2O 2.2g, CuSO 4 ·5H 2 O 1.57 g, CoCl 2 6H 2 O 1.6g, distilled water 1L. Nitrate nitrogen DM medium formula is: KNO3 1 g; sodium succinate 16.88g; Na 2 HPO 4 12H 2 O 10.55g; KH 2 PO 4 1.5 g; MgSO 4 7H 2 O0.1g; trace elements 2.0 mL; pH 7.2-7.5, distilled water 1L. Trace elements: Na 2 EDTA 50g, CaCl 2 5.5 g, MnCl 2 ·4H 2 O 5.06 g, FeSO 4 5g, ZnSO 4 7H2O 2.2g, CuSO 4 ·5H 2 O 1.57 g, CoCl 2 6H 2 O 1.6g, distilled water 1L. Nitrite DM medium formula: NaNO2 1.5g; sodium succinate 16.88g; Na 2 HPO 4 12H 2 O10.55g; KH 2 PO 4 1.5 g; MgSO 4 7H 2 O 0.1g; trace elements 2.0 mL; pH 7.2-7.5, distilled water 1L. Trace elements: Na 2 EDTA 50g, CaCl 2 5.5 g, MnCl 2 ·4H 2 O 5.06 g, FeSO 4 5g, ZnSO 4 7H2O 2.2g, CuSO 4 ·5H 2 O 1.57 g, CoCl 2 6H 2 O 1.6 g, distilled water 1 L. Finally, the YB079 strain was obtained.

[0052] The strain morphology of the obtained strain YB079 is shown in Figure 1 , Colony morphological characteristics: The colonies are orange-red, round, opaque, smooth, and have neat edges.

[0053] The morphology of strain YB079 was observed using a scanning electron microscope and the strain was short rod or spherical. Figure 2 shown.

[0054] The YB079 strain was cultured for 2-3 days, 3OD of bacterial cells were collected, DNA was extracted using a bacterial DNA extraction kit, and PCR amplification was performed using bacterial universal primers 27F: 5′-AGAGTTTGATCMTGGCTCAG-3′ (SEQ ID NO.2), 1492R: 5′-TACGGYTACCTTGTTACGACTT-3′ (SEQ ID NO.3), and agarose gel electrophoresis (1%) was used for verification; the amplified PCR product was sequenced and analyzed by Shanghai Sangon Biotechnology Co., Ltd. The 16S rDNA sequence of the strain was obtained as shown in SEQ ID NO.1.

[0055] The sequencing results were compared with the existing 16S rDNA sequences in the GenBank database to obtain similar sequences, and phylogenetic tree analysis was performed using MEGA X. The constructed phylogenetic tree is shown in Figure 3 The results showed that the 16S rDNA sequence of the strain was consistent with that of Hydizia Dietzia maris The 16S rDNA sequence similarity of the strain was 100%. Dietzia maris .

[0056] Example 2

[0057] Growth characteristics of strain YB079

[0058] The growth of YB079 in LB medium is shown in Figure 4. YB079 was inoculated into fresh LB culture medium and cultured under aerobic, static and anaerobic conditions, and the growth of the strain was observed, and the biomass (OD600) of YB079 under different oxygen content conditions was compared. The results showed that the biomass of the bacteria under shaking conditions was slightly higher than that under static conditions, and significantly higher than that under anaerobic conditions. Under shaking culture conditions, the OD value of the strain increased from 0.279 to 1.211 in 67 hours, and under static culture conditions, the OD value of the strain increased from 0.268 to 0.721 in 67 hours, while under anaerobic culture conditions, the OD increased slowly, and the OD value of the strain only increased from 0.279 to 0.309 in 67 hours. It can be seen that YB079 can grow under conditions of different oxygen contents, and sufficient oxygen is more conducive to the growth of YB079. The aerobic condition was shaking culture in a constant temperature shaker (200 r / min), the static condition was static culture in a biochemical incubator, and the anaerobic condition was placing the test tube containing the bacterial solution into an anaerobic tank, extracting oxygen and sealing it, and then placing it in a biochemical incubator for static culture. The culture temperature was 28 °C.

[0059] Example 3

[0060] Effect of oxygen on nitrogen removal ability of YB079

[0061] YB079 was inoculated into DM culture medium and NH 4 Cl, NaNO 2 、KNO 3 The strains were cultured under aerobic, static and anaerobic conditions, and their ability to remove ammonia nitrogen, nitrate nitrogen and nitrite nitrogen, as well as their growth conditions (OD600) were tested. The aerobic condition was cultured in a constant temperature shaker (200r / min), the static condition was cultured in a biochemical incubator, and the anaerobic condition was to place the test tubes containing the bacterial solution in an anaerobic tank, extract oxygen and seal it, and then place it in a biochemical incubator for static culture. The culture temperature was 28°C.

[0062] YB079 has the strongest ammonia nitrogen removal ability under aerobic conditions, removing 57.21% of 440 mg / L ammonia nitrogen in 120 hours. Under anaerobic conditions, the strain cannot remove ammonia nitrogen. However, under static conditions, YB079 removes 38.24% of ammonia nitrogen in 120 hours. The strain grows faster under aerobic conditions and grows better under static culture, but grows slower under anaerobic conditions. The specific results are shown in Figure 5 .

[0063] YB079 can effectively remove nitrite nitrogen under anaerobic, aerobic and static conditions, and remove 720 mg / L nitrite nitrogen by 100%, 100% and 97.52% respectively in 120 hours. The strain can grow well under aerobic and static culture conditions under the condition of nitrite nitrogen as the nitrogen source, but poorly under anaerobic conditions. The results are shown in Figure 6 .

[0064] YB079 can effectively remove nitrate nitrogen under anaerobic, aerobic and static conditions, and remove 96.77%, 99.94% and 100% of 140 mg / L nitrate nitrogen in 120 hours respectively. The growth of the strains is faster under aerobic conditions, better under static conditions, and slower under anaerobic conditions. Figure 7 .

[0065] Example 4

[0066] Effects of different nitrogen concentrations on nitrogen removal by YB079 bacteria

[0067] YB079 bacteria were inoculated into DM culture medium containing 100, 200, 400, and 600 mg / L of ammonia nitrogen, and the ammonia nitrogen concentration in the samples was detected regularly. The ability of YB079 to remove ammonia nitrogen is shown in the following table. Figure 8 . When the concentration of ammonia nitrogen in the culture medium is 100 and 200 mg / L, the ammonia nitrogen can be completely removed within 72 and 96 hours. When the concentration of ammonia nitrogen in the culture medium is 400 mg / L, the ammonia nitrogen concentration can be reduced to 68 mg / L within 120 hours, and the removal rate is 82%. When the concentration of ammonia nitrogen in the culture medium is 600 mg / L, the ammonia nitrogen concentration can be reduced to 243 mg / L within 120 hours, and the removal rate is 57.99%. It can be seen that the time required for complete degradation increases with the increase of ammonia nitrogen concentration. YB079 bacteria has a high ability to remove ammonia nitrogen.

[0068] YB079 bacteria were inoculated into DM culture medium containing 200, 400, 600, and 800 mg / L of nitrite nitrogen, and the nitrite nitrogen concentration in the samples was detected regularly. The ability of YB079 to remove nitrite nitrogen is shown in the results. Fig. 9 . When the concentration of nitrite nitrogen in the culture medium was 200, 400, and 600 mg / L, the nitrite nitrogen could be completely removed within 72, 96, and 120 hours. When the concentration of nitrite nitrogen in the culture medium was 800 mg / L, the concentration of nitrite nitrogen could be reduced to 590 mg / L within 120 hours, and the removal rate was 25.3%. It can be seen that the time required for complete degradation increases with the increase of nitrite nitrogen concentration. YB079 bacteria has a high ability to remove nitrite nitrogen.

[0069] YB079 bacteria were inoculated into DM culture medium containing 75, 165, 245, and 325 mg / L of nitrate nitrogen, and the nitrate nitrogen concentration in the samples was detected regularly. The ability of YB079 to remove nitrate nitrogen is shown in the following table. Fig.10 . When the concentration of nitrate nitrogen in the culture solution was 75, 165, and 245 mg / L, all nitrate nitrogen could be removed within 120 hours. When the concentration of nitrate nitrogen in the culture solution was 325 mg / L, the concentration of nitrate nitrogen could be reduced to 71 mg / L within 120 hours, and the removal rate was 78.28%. It can be seen that the time required for complete degradation increases with the increase of nitrate nitrogen concentration. YB079 bacteria has a high ability to remove nitrate nitrogen.

[0070] Example 5

[0071] Nitrogen removal ability of YB079 bacteria in food waste leachate

[0072] Preparation method of leachate from kitchen waste: put kitchen waste into a bucket, add appropriate amount of deionized water, and leave it for 3 days. Take the filtrate, put it into a beaker, add appropriate amount of deionized water to dilute it, put it in the refrigerator, and remove the oil layer after the oil in the filtrate is agglomerated. Centrifuge the remaining filtrate at 8000r / min for 5min, collect the supernatant, and then use a 0.45μm aqueous filter membrane to filter twice, collect the filtrate, add 0.5g / L ammonium chloride, 1g / L potassium nitrate, and 1g / L sodium nitrite to the obtained filtrate, and adjust the pH to 7.5. Take 25mL of the filtrate into a 100mL conical flask, make a total of 6 bottles, and sterilize them with high-pressure steam at 121℃ for 20min. Add bacterial inoculum with an OD value of 0.4-0.6 to 3 bottles, and do not inoculate the other 3 bottles as controls. The six bottles were placed in a 28°C constant temperature shaker for shaking (200 r / min) culture. Samples were taken at 0 and 14 hours to determine the ammonia nitrogen, nitrate nitrogen and nitrite nitrogen contents in the leachate of the kitchen waste. The results are shown in Fig.11 .

[0073] The results showed that YB079 removed ammonia nitrogen, nitrate nitrogen, and nitrite nitrogen from nitrogen-contaminated kitchen filtrate within 114 hours. In the experimental group with strain YB079 added, when the initial ammonia nitrogen concentration in the water sample was 270 mg / L, the ammonia nitrogen in the kitchen filtrate could be completely removed; when the initial nitrate nitrogen concentration was 190 mg / L, the nitrate nitrogen removal rate within 114 hours was 98.51%; when the initial nitrite nitrogen concentration was 390 mg / L, all nitrite nitrogen could be removed within 114 hours; the OD value of the strain also increased from 0.832 to 5.78 within 114 hours. In the blank group without strain YB079 added, the ammonia nitrogen, nitrate nitrogen, nitrite nitrogen content and bacterial concentration remained basically unchanged.

[0074] Example 6

[0075] Nitrogen removal capacity of YB079 bacteria in polluted pond sediment

[0076] Preparation method of contaminated sludge: Take fresh sludge about 10 cm below the mud level from the pond. Preliminarily filter out large debris such as leaves and branches, and then obtain the sludge required for the experiment through a filter. Take 25 g of the prepared sludge into a 100 mL conical flask, add 25 ml of deionized water containing 0.5 g / L ammonium chloride, 1 g / L potassium nitrate, and 1 g / L sodium nitrite, mix thoroughly, make 6 bottles in total, and adjust the pH to 7.5. Sterilize twice with high-pressure steam at 121°C for 20 min. Add bacterial inoculum with an OD value of 0.4-0.6 to 3 bottles, and do not inoculate the other 3 bottles as controls. Place the 6 bottles in a 28°C constant temperature shaker for shaking (200 r / min) culture, take samples at 0 and 114 hours, and determine the content of ammonia nitrogen, nitrate nitrogen, and nitrite nitrogen in the sludge. See the results. Fig.12 .

[0077] The results show the removal of ammonia nitrogen, nitrate nitrogen and nitrite nitrogen in nitrogen-contaminated sludge by YB079 within 114 hours. The concentration of nitrogen that can be extracted from the sludge is low, and most of it is not extracted because the adsorption of sludge is too strong, causing most of the nitrogen to be adsorbed in the sludge. After 114 hours, when the initial ammonia nitrogen concentration in the water sample of the experimental group with strain YB079 added was 110 mg / L, the removal rate of ammonia nitrogen within 114 hours was 81.24%; when the initial nitrate nitrogen concentration was 65 mg / L, the removal rate of nitrate nitrogen within 114 hours was 92.77%; when the initial nitrite nitrogen concentration was 170 mg / L, the removal rate of nitrite nitrogen within 114 hours was 91.78%. The contents of ammonia nitrogen, nitrate nitrogen and nitrite nitrogen in the blank group without strain YB079 added remained basically unchanged.

Claims

1. A bacterial strain, Hydizia hydizia YB079, classified and named Dietzia maris YB079, deposited in the China Center for Type Culture Collection, the deposit address is Wuhan University, Wuhan, China, the deposit number is CCTCC NO: M 20221251, the deposit date is August 8, 2022.

2. Use of the strain according to claim 1 in biological denitrification in nitrogen-containing wastewater.

3. The use according to claim 2, characterized in that: The nitrogen-containing wastewater includes leachate from kitchen waste or polluted pond sludge.

4. The use according to claim 2, characterized in that: The strain is used to remove one or more of ammonia nitrogen, nitrate nitrogen and nitrite nitrogen in nitrogen-containing wastewater.

5. The use according to claim 4, characterized in that: The strain removes nitrogen-containing wastewater by oxidizing ammonia nitrogen, reducing nitrate nitrogen, and reducing nitrite nitrogen.

6. The use according to claim 5, characterized in that: In the process of removing nitrogen-containing wastewater, ammonia nitrogen is removed in an aerobic or air-stagnant environment; or one or both of nitrate nitrogen and nitrite nitrogen are removed in an aerobic or air-stagnant or anaerobic environment.

7. A biological denitrification agent, characterized in that: The medicament comprises the bacterial strain Hydizia hydizia YB079 described in claim 1, which is classified and named Dietzia maris YB079 is deposited in China Center for Type Culture Collection, Wuhan University, Wuhan, China, with the deposit number CCTCC NO: M 20221251.

8. The biological denitrification agent according to claim 7, characterized in that: The biological denitrification agent is used for biological denitrification in nitrogen-containing sewage, wherein the nitrogen-containing sewage includes leachate from kitchen waste or polluted pond sludge.

9. The biological denitrification agent according to claim 8, characterized in that: The strain is used to remove one or more of ammonia nitrogen, nitrate nitrogen and nitrite nitrogen in nitrogen-containing wastewater. The nitrogen-containing wastewater removal process is carried out in an aerobic or air static environment; or one or both of nitrate nitrogen and nitrite nitrogen are removed in an anaerobic environment.

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