Symbiotic flora of salt lake halotolerant bacteria and anaerobic ammonium oxidation bacteria and application of symbiotic flora

Abstract

The invention discloses a symbiotic flora of salt lake halotolerant bacteria and anaerobic ammonium oxidation bacteria and application of the symbiotic flora, the symbiotic flora comprises the salt lake halotolerant bacteria and the anaerobic ammonium oxidation bacteria, and the anaerobic ammonium oxidation bacteria are freshwater bacteria and comprise at least one of Ca.Broaddia and Ca.Kuenia. According to the application, a biological enhancement strategy is adopted, salt lake halotolerant bacteria are introduced into an anaerobic ammonium oxidation system, a symbiotic system of the salt lake halotolerant bacteria and anaerobic ammonium oxidation bacteria is constructed, the flora structure and function of the anaerobic ammonium oxidation bacteria are optimized by utilizing the synergistic effect of the flora, and the anaerobic ammonium oxidation bacteria are optimized. The salt resistance and the stability of an anaerobic ammonium oxidation system applied to wastewater denitrification treatment are improved (the anaerobic ammonium oxidation bacteria can tolerate and stably denitrify under the condition that the salt content is greater than or equal to 3.5% or even 4% in terms of sodium chloride).

Description

Technical Field

[0001] The present application relates to the technical field of wastewater treatment, and in particular to a symbiotic bacterial community of salt lake salt-tolerant bacteria and anaerobic ammonia-oxidizing bacteria and applications thereof. Background Art

[0002] With the development of industries such as seafood processing, salting, and leather tanning, the discharge of nitrogen-rich, high-salinity wastewater has rapidly increased, accounting for 5% of the global wastewater treatment demand. High-salinity wastewater refers to industrial or domestic wastewater with a total dissolved solids (TDS) content ≥3.5% or a salt content ≥1% (calculated as sodium chloride). Discharging untreated nitrogen-rich, high-salinity wastewater can lead to eutrophication and, in severe cases, cause black and odorous water, posing a threat to aquatic ecosystems.

[0003] Denitrification technologies for high-salinity wastewater mainly include physical, chemical and biological methods. Physical and chemical technologies such as membrane separation, ion exchange and advanced oxidation processes have problems such as high cost and secondary pollution during the startup process. Biological methods have attracted much attention due to their low operating cost, environmental friendliness and high treatment efficiency. Traditional biological denitrification processes mainly rely on the nitrification-denitrification process, which is the conversion of ammonia nitrogen (NH 4+ -N) is oxidized to nitrite nitrogen (NO2 - -N) and nitrate nitrogen (NO3 - -N), and then reduced to nitrogen (N2) by denitrifying bacteria. Anaerobic ammonium oxidation (Anammox) process is a new biological denitrification process for wastewater denitrification. Anaerobic ammonium oxidizing bacteria (AnAOB) can directly utilize nitrite nitrogen (NO2 - -N) as an electron acceptor, and under anaerobic conditions, it reacts with ammonia nitrogen (NH 4+ -N) to produce nitrogen (and a small amount of nitrate nitrogen (NO3 - -N). According to empirical formulas, the anaerobic ammonium oxidation process alone can remove up to 89% of nitrogen from wastewater (the reaction equation is: Compared to traditional nitrification-denitrification, the anaerobic ammonium oxidation process offers significant advantages, including reducing oxygen demand by approximately 60%, organic carbon source demand by 100%, virtually eliminating greenhouse gas emissions, and reducing sludge production by 90%. However, high salinity (>1%) can cause osmotic stress on microbial cells, inhibiting the anaerobic ammonium oxidation activity of anaerobic ammonium-oxidizing bacteria and causing a decrease in or even collapse of the reaction system's denitrification performance.

[0004] At present, there are two main strategies for biological denitrification of high-salinity wastewater: (1) Directed enrichment of Marine Anammox Bacteria (MAB): Enriching marine anammox bacteria from brackish water and marine sediments, and utilizing their natural salt tolerance to treat high-salinity denitrification wastewater. Representative bacterial genus Ca. Scalindua It can survive in salinity environments up to 10%, and the minimum survival salinity requirement is 1%. However, its doubling period is extremely long (up to 14.4 days), and it is extremely sensitive to environmental factors such as substrate concentration and ion composition (enrichment depends on seawater matrix simulation (containing specific ions such as Mg 2+ / Na + =0.11)), has strict requirements for growth environment, and is easily replaced by freshwater bacteria in artificial saline environment, which limits the Ca. Scalindua (2) Salinity acclimation and compatible solute addition of freshwater anammox bacteria (FAB): Ca. Brocade , Ca. Spread Using FAB as the research object, we improved their salt tolerance to ≤3% NaCl through salt gradient acclimation. The salinity threshold of FAB acclimation is related to the anaerobic ammonium oxide species, sludge concentration, and experimental conditions. Brocade The tolerance to salinity is low and it is inhibited when the salinity reaches 0.4%. Ca. Spread It has a higher tolerance to salinity, and long-term salt gradient acclimation can make Ca. Spread Although anaerobic ammonium oxidizing bacteria can adapt to salinity levels below 3%, long-term exposure to high-salinity stress can still result in prolonged doubling times and reduced denitrification activity. Compatible solutes are polar, easily soluble, low-molecular-weight organic compounds that can resist the stress posed by high osmotic pressure and other environmental stresses (such as low temperature, freezing, high temperature, desiccation, and starvation) on microorganisms. They can also act as protein stabilizers under high ionic strength conditions. By adding exogenous compatible solutes, the osmotic pressure of anaerobic ammonium oxidizing bacteria can be adjusted, restoring their osmotic pressure balance in the short term and improving denitrification efficiency. However, these solutes have disadvantages such as high cost, the need for a continuous supply of compatible solutes, and unstable effects.

[0005] Therefore, there is an urgent need to develop a more convenient and efficient salt-tolerant biological denitrification technology. Summary of the Invention

[0006] The present application provides a symbiotic bacterial community of salt lake salt-tolerant bacteria and anaerobic ammonia-oxidizing bacteria and its application, which is used to solve the problem that the existing high-salt wastewater biological denitrification technology has poor or unstable effects.

[0007] The present application discloses a symbiotic bacterial community of salt lake salt-tolerant bacteria and anaerobic ammonia-oxidizing bacteria, wherein the anaerobic ammonia-oxidizing bacteria are freshwater bacteria, including Ca. Broadia and Ca. Spread At least one of them. This application adopts a bioaugmentation strategy to introduce salt lake salt-tolerant bacteria into the anaerobic ammonium oxidation system of high-salt wastewater. Salt lake salt-tolerant bacteria have unique physiological adaptability in high-salt environments, can regulate cell osmotic pressure to maintain physiological functions, and can build a symbiotic system with anaerobic ammonium oxidizing bacteria. The synergistic effect of the flora is used to optimize the flora structure and function of anaerobic ammonium oxidizing bacteria, thereby improving the salt tolerance and stability of the anaerobic ammonium oxidizing system (generally, anaerobic ammonium oxidizing bacteria can only withstand a maximum salt content of 3% calculated as sodium chloride. The symbiotic colony of this application can tolerate and stably denitrify under conditions where the salt content is ≥3.5% or even 4% calculated as sodium chloride), and can ensure the growth advantage of anaerobic ammonium oxidizing bacteria without the need for a continuous supply of exogenous compatible solutes.

[0008] In one implementation of the present application, the symbiotic bacterial community is a mixed bacterial powder, a mixed bacterial culture or an activated sludge. That is, the product form or dosage form of the symbiotic bacterial community can be a mixed bacterial powder, a mixed bacterial culture or an activated sludge. Mixed bacterial powder refers to a powdered mixed bacterial agent containing a symbiotic bacterial community, which is easy to store and can be directly added to the wastewater denitrification reactor when used. A mixed bacterial culture refers to a culture system containing a symbiotic bacterial community, which can be put into use without recovery when used. Activated sludge refers to a flocculent biological community containing a symbiotic bacterial community formed by aeration culture during the sewage treatment process, and has a low production cost.

[0009] In one implementation of the present application, the biomass ratio of the anaerobic ammonia-oxidizing bacteria and the salt lake salt-tolerant bacteria is 0.5 to 2. Thus, good symbiosis and denitrification performance can be achieved.

[0010] In one implementation of the present application, the anaerobic ammonia oxidizing bacteria include at least Ca. Spread .

[0011] In one implementation of the present application, the salt lake salt-tolerant bacteria include the following genera: Zeimonas, SURF-28, Promineifilum, and BOKV01. In the present application, metagenomic sequencing analysis showed that the relative abundance of Zeimonas, SURF-28, Promineifilum, and BOKV01 was high in the high-salinity anaerobic ammonium oxidation system, and they may play a major symbiotic role with the anaerobic ammonium oxidizers.

[0012] In one implementation of the present application, among the salt lake halotolerant bacteria, in terms of relative abundance, the salt lake halotolerant bacteria include 40% to 55% of Zeimonas, 8% to 15% of SURF-28, 5% to 10% of Promineifilum and 4% to 8% of BOKV01.

[0013] In one implementation of the present application, the salt lake salt-tolerant bacteria also include at least one or more of the following genera: JACQPU01, Vreelandella, BM516, Nitrosomonas, Flexicrinis, Denitrolinea, JAJVHZ01, JAABRB01, UTPRO1, JAHDWY01, Pseudorhodoplanes, UBA2336, DSQQ01, Brocadia, JABLXU01, and Sulfurivermis.

[0014] This application also discloses the use of a symbiotic bacterial consortium in wastewater denitrification treatment. It should be noted that the symbiotic bacterial consortium used in this application for wastewater denitrification treatment exhibits good salt tolerance (in one specific embodiment, it can tolerate an environment with a salinity of 4% as measured by sodium chloride, with anaerobic ammonia-oxidizing bacteria growing well and maintaining good denitrification performance in this high-salinity environment).

[0015] In one implementation of the present application, the wastewater has a salinity of ≥1% calculated as sodium chloride; and / or the wastewater has a salinity of 3.5% to 4% calculated as sodium chloride. It should be noted that the symbiotic bacterial consortium of the present application, when used for wastewater denitrification treatment, can tolerate a higher salinity (≥3.5%). In one specific embodiment, it can tolerate an environment with a salinity of 4% calculated as sodium chloride.

[0016] In one implementation of the present application, the biomass of the symbiotic bacteria in the wastewater is 2.5 g / L to 5 g / L, thereby achieving better denitrification performance.

[0017] The beneficial effects of this application are: The present application adopts a bioaugmentation strategy to introduce salt lake salt-tolerant bacteria into the anaerobic ammonium oxidation system of high-salt wastewater. Salt lake salt-tolerant bacteria have unique physiological adaptability in high-salt environments, can regulate cell osmotic pressure to maintain physiological functions, and can build a symbiotic system with anaerobic ammonium oxidizing bacteria. The synergistic effect of the flora is used to optimize the flora structure and function of anaerobic ammonium oxidizing bacteria, thereby improving the salt tolerance and stability of the anaerobic ammonium oxidizing system (generally, anaerobic ammonium oxidizing bacteria can only withstand a maximum salt content of 3% calculated as sodium chloride. The symbiotic colonies of the present application can tolerate and stably denitrify under conditions where the salt content is ≥3.5% or even 4% calculated as sodium chloride), and can ensure the growth advantage of anaerobic ammonium oxidizing bacteria without the need for a continuous supply of exogenous compatible solutes. In addition, the symbiotic flora of the present application can tolerate a higher salinity environment through an acclimation time of about 65 days. Compared with conventional anaerobic ammonium oxidizing systems, the acclimation time can be shortened by about half, which can reduce the operating cost of the reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1Graphs showing nitrogen concentration results of inlet and outlet water and nitrogen removal results of each group of anaerobic ammonium oxidation systems involved in the embodiments of the present application are shown.

[0019] Figure 2 The anaerobic ammonium oxidizing bacteria Ca. Broadia and Ca. Spread The change of relative abundance of . DETAILED DESCRIPTION

[0020] The present invention is further described in detail below by specific embodiments in conjunction with the accompanying drawings. In the following embodiments, many detailed descriptions are intended to enable the present application to be better understood. However, those skilled in the art can readily appreciate that some of the features may be omitted in different circumstances, or may be replaced by other materials or methods. In some cases, some operations related to the present application are not shown or described in the specification. This is to avoid the core of the present application being overwhelmed by excessive descriptions, and for those skilled in the art, it is not necessary to describe these related operations in detail. They can fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0021] In addition, the features, operations, or characteristics described in the specification may be combined in any appropriate manner to form various embodiments. Furthermore, the steps or actions in the method description may be reordered or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various sequences in the specification and drawings are provided solely for the purpose of clearly describing a particular embodiment and are not intended to be mandatory, unless otherwise specified.

[0022] The serial numbers assigned to the components in this document, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning.

[0023] The present application provides a symbiotic bacterial community comprising salt lake halotolerant bacteria and anaerobic ammonium oxidizing bacteria. In an anaerobic ammonium oxidation system for high-salt wastewater, the salt lake halotolerant bacteria can form a symbiotic system with the anaerobic ammonium oxidizing bacteria, utilizing the synergistic effect of the bacterial community to optimize the structure and function of the anaerobic ammonium oxidizing bacteria, thereby improving the salt tolerance and denitrification stability of the anaerobic ammonium oxidizing system.

[0024] In a specific embodiment, the symbiotic bacteria community can be a mixed bacterial powder, a mixed bacterial culture or activated sludge. That is, the product form or dosage form of the symbiotic bacteria community can be a mixed bacterial powder, a mixed bacterial culture or activated sludge. Mixed bacterial powder refers to a powdered mixed bacterial agent containing symbiotic bacteria, which is easy to store and can be directly added to the wastewater denitrification reactor when used. Mixed bacterial culture refers to a culture system containing symbiotic bacteria, which can be put into use without recovery when used. Activated sludge refers to a flocculent biological community containing symbiotic bacteria formed by aeration culture during the sewage treatment process, and has a low production cost.

[0025] In one embodiment, the anaerobic ammonium oxidizing bacteria are freshwater bacteria, including Ca. Broadia and Ca. Spread At least one of .

[0026] In one embodiment, the anaerobic ammonium oxidizing bacteria include at least Ca. Spread .

[0027] In a specific embodiment, the biomass ratio of the anaerobic ammonium oxidizing bacteria to the salt lake halophilic bacteria can be 0.5 to 2. For example, the biomass ratio of the anaerobic ammonium oxidizing bacteria to the salt lake halophilic bacteria can be 0.5, 0.8, 1, 1.5, or 2. It should be noted that biomass refers to the total amount of organisms per unit area or volume within a specific time period, and generally refers to the total mass of a microbial population.

[0028] In one embodiment, salt lake salt-tolerant bacteria may include the following genera: Zeimonas, SURF-28, Promineifilum, and BOKV01. In this application, metagenomic sequencing analysis showed that Zeimonas, SURF-28, Promineifilum, and BOKV01 were relatively abundant in the high-salinity anaerobic ammonium oxidation system and may play a major symbiotic role with anaerobic ammonium oxidizers.

[0029] In a specific embodiment, the salt lake halotolerant bacteria may include 40% to 55% Zeimonas in relative abundance. For example, the salt lake halotolerant bacteria may include 40%, 45%, 50%, or 55% Zeimonas in relative abundance.

[0030] In a specific embodiment, the salt lake halotolerant bacteria may include 8% to 15% SURF-28 in terms of relative abundance. For example, the salt lake halotolerant bacteria may include 8%, 10%, 12%, or 15% SURF-28 in terms of relative abundance.

[0031] In a specific embodiment, the salt lake halotolerant bacteria may include 5% to 10% of Promineifilum in terms of relative abundance. For example, the salt lake halotolerant bacteria may include 5%, 8%, or 10% of Promineifilum in terms of relative abundance.

[0032] In a specific embodiment, based on relative abundance, the salt lake halotolerant bacteria may include 4% to 8% of BOKV01. For example, based on relative abundance, the salt lake halotolerant bacteria may include 4%, 6%, or 8% of BOKV01.

[0033] In a specific embodiment, the salt lake salt-tolerant bacteria may also include at least one or more of the following genera: JACQPU01, Vreelandella, BM516, Nitrosomonas, Flexicrinis, Denitrolinea, JAJVHZ01, JAABRB01, UTPRO1, JAHDWY01, Pseudorhodoplanes, UBA2336, DSQQ01, Brocadia, JABLXU01, and Sulfurivermis.

[0034] In one embodiment, the symbiotic bacteria are used for denitrification treatment of wastewater.

[0035] The present application also provides an application of a symbiotic bacterial community in wastewater denitrification treatment.

[0036] In one specific embodiment, the wastewater is high-salinity wastewater. High-salinity wastewater refers to wastewater with a total dissolved solids (TDS) ≥ 3.5% or a salt content ≥ 1% calculated as sodium chloride. It should be noted that the unit of salt content or salinity (%) used in this application represents a mass percentage. For example, a salinity of 1% calculated as sodium chloride means that 100g of wastewater contains 1g of sodium chloride.

[0037] In one embodiment, the wastewater has a salt content of ≥3% calculated as sodium chloride. For example, the wastewater has a salt content of 3%, 3.5%, or 4% calculated as sodium chloride. The symbiotic bacterial consortium of the present application, through symbiotic and synergistic interactions, can tolerate high-salt environments and maintain good growth even when the salt content is ≥3.5%, and the anaerobic ammonia-oxidizing bacteria can maintain a relatively stable denitrification capacity.

[0038] In a specific embodiment, the salt content of the wastewater is 3.5% to 4% in terms of sodium chloride.

[0039] In one embodiment, in a reactor containing wastewater and symbiotic bacteria, the biomass of the symbiotic bacteria may be 2.5 g / L to 5 g / L. For example, the biomass of the symbiotic bacteria may be 2.5 g / L, 3 g / L, 3.5 g / L, 4 g / L, 4.5 g / L, or 5 g / L.

[0040] The present application also provides a method for treating high-salt wastewater, comprising: using the symbiotic bacterial community of the present application to denitrify the high-salt wastewater.

[0041] The present invention is further described in detail below by specific experimental process and experimental data examples. The following examples are only used to further illustrate the present invention and should not be construed as limiting the present invention. In the present embodiment, unless otherwise specified, the reagents and instruments used are all commercially available, and the experimental operations are all carried out in accordance with the product specifications and conventional experimental specifications.

[0042] (1) Experimental materials and experimental settings Salt Lake Halophiles: Surface sediments collected in 2024 from Barkol Lake (43°36′N, 92°49′E) and Huancai Lake (43°21′N, 94°13′E) in Xinjiang were stored at room temperature and protected from light. Salt Lake Halophiles exhibit unique physiological adaptability in high-salinity environments (exemplified by Barkol Lake (6%) and Huancai Lake (10%) in Xinjiang), capable of regulating cellular osmotic pressure to maintain physiological functions.

[0043] Anaerobic ammonium oxidizing bacteria: Anaerobic ammonium oxidizing sludge was purchased from a conventional anaerobic ammonium oxidizing reactor of a sewage treatment plant, containing anaerobic ammonium oxidizing bacteria Ca. Broadia sapporensis and Ca. Spread of stuttgartiensis , among which, Ca. Broadia sapporensis and Ca. Spread of stuttgartiensis The ratio of biomass is 1:4.

[0044] Group setting: set up 1 experimental group and 2 control groups, namely: Experimental group: ANAMMOX sludge and salt lake sediments (Balikun and Huancai Lake) were mixed at a biomass ratio of 1:1 and then inoculated into the reactor.

[0045] Control group 1: Only the same amount of anaerobic ammonium-oxidizing bacteria as those in the experimental group were inoculated into the reactor.

[0046] Control group 2: Based on the control group 1, glutamate was continuously added to the reactor to maintain the concentration of glutamate in the reactor at 60 μg / L.

[0047] The biomass, that is, the mixed liquor volatile suspended solids concentration (MLVSS) of the three groups of reactors was 3 g / L.

[0048] (2) Reactor operation and salinity gradient acclimation The experiments were conducted using a triple-connected 1.5L membrane bioreactor (MBR). The reactor body was constructed from plexiglass and contained the membrane, inlet and outlet water, agitator, aerator, sampling device, and multi-parameter control systems for dissolved oxygen, pH, and temperature. The inlet and outlet water flowed continuously, with agitator set at 100 rpm and a temperature maintained at 35 ± 1°C. The hydraulic retention time (HRT) (the average residence time of the treated wastewater within the reactor, i.e., the average reaction time between the wastewater and the microorganisms within the bioreactor) was set at 24 hours. Aeration was performed by sparging a mixture of 95% argon (Ar) and 5% CO2 into the system to maintain a pH between 6.8 and 8.0. The membrane pore size was 0.1 mm to effectively intercept the anammox sludge in the system.

[0049] The experimental wastewater used artificially prepared nitrogen-containing simulated wastewater, ammonia nitrogen (NH 4+ -N) is added in the form of ammonium sulfate, nitrite nitrogen (NO2 - -N) was added in the form of sodium nitrite, sodium bicarbonate served as an inorganic carbon source, and a trace element solution provided metal ions and inorganic salts. Salinity was adjusted by adding sodium chloride (NaCl). For example, a 1% salinity represents 1g of NaCl per 100g of solution. N2 was introduced for 20 minutes before entering the reactor to remove oxygen. The experimental wastewater ratios are shown in the table below:

[0050] Wherein, the proportion of trace element solution I is shown in the following table:

[0051] The proportions of trace element solution II are shown in the table below:

[0052] The initial operating salinity for Controls 1 and 2 was 0%, and the initial influent nitrite and ammonia nitrogen concentrations were both set at 150 mg N / L (representing 150 mg of nitrogen per liter of solution). Due to the addition of halotolerant bacteria, the initial salinity for the experimental group was set at 1%. To mitigate the ecological perturbation of the anaerobic ammonium-oxidizing bacterial flora caused by the introduction of halotolerant bacteria, the initial influent nitrite and ammonia nitrogen concentrations for the experimental group were adjusted to 25 mg N / L and 50 mg N / L, respectively, after inoculation. The nitrogen loading was then gradually increased until the nitrite and ammonia nitrogen concentrations reached 150 mg N / L, once the reactor operation stabilized.

[0053] The salinity of the experimental group and two control groups was gradually increased, with a salinity gradient of 0.5% or 1%. The next step of salinity increase was initiated when the effluent nitrogen concentration remained stable and showed no significant fluctuations for at least two consecutive hydraulic retention times (HRT) (one HRT was 24 hours) under the new salinity conditions.

[0054] (3) Anaerobic ammonium oxidation performance evaluation During the experiment, effluent samples were collected every 2-3 days and the NH4 + 、NO2 - 、NO3 - The total nitrogen (TN) removal rate, nitrogen removal rate (NRR) and nitrogen loading rate (NLR) were calculated based on the concentration of nitrogen. Figure 1 The graphs of nitrogen concentration in the inlet and outlet water and nitrogen removal results of each group of anaerobic ammonium oxidation systems involved in the embodiments of the present application are shown, wherein: Figure 1 (a), (c), and (e) are the results of the inlet and outlet nitrogen concentrations of the control group 1, the control group 2, and the experimental group, respectively. The horizontal axis represents the acclimatization time and salinity, and the vertical axis represents the inlet and outlet nitrogen concentrations. The inlet refers to the wastewater fed into the reactor, and the outlet refers to the treated wastewater discharged from the reactor. Figure 1 (b), (d), and (f) are the total nitrogen (TN) removal rates, nitrogen removal load (NRR), and nitrogen loading rate (NLR) change curves of control group 1, control group 2, and experimental group, respectively. The horizontal axis represents the acclimatization time and salinity.

[0055] Depend on Figure 1 It can be seen that after 112 days of salinity gradient acclimation, the control group 1 (conventional anaerobic ammonium oxidation system) could only withstand a maximum salinity of 3%, and the reactor collapsed when the salinity increased to 3.5%. In contrast, the control group 2 (conventional salt lake salt-tolerant bacteria with glutamate added) could withstand a salinity of 3.5% after 112 days of salinity gradient acclimation, and the reactor collapsed when the salinity increased to 4%. In contrast, the experimental group (enhanced system with salt lake salt-tolerant bacteria added) was able to tolerate a salinity of up to 4% after only 65 days of acclimation, breaking through the salinity tolerance threshold of control groups 1 and 2, shortening the reactor acclimation time by nearly 50%, and still maintaining a total nitrogen removal rate of more than 80% at a high salinity of 4%, showing significant advantages in both salt tolerance and denitrification performance.

[0056] (4) Analysis of bacterial community structure Metagenomic sequencing was performed on the anaerobic ammonium oxidation systems of control group 1, control group 2, and experimental group at different salinity periods (salinity 1%, 2%, 2.5%, 3%, 3.5%, and 4%).

[0057] Figure 2 The anaerobic ammonium oxidizing bacteria Ca. Broadia and Ca. Spread The graph of the relative abundance of Ca. Spread When the relative abundance is 5% and the salinity increases to 3%, Ca. Spread The relative abundance increased significantly to 22%, which was similar to the increase in the Ca. Spread The increases were 55% and 45% higher, respectively, indicating that the presence of salt-tolerant bacteria in salt lakes can synergistically promote the growth of Ca. Spread energy metabolism (better anaerobic ammonium oxidation performance) and competitive advantages (better salt tolerance, Ca. Spread have a higher relative abundance).

[0058] A total of 290 complete high-quality genomes were obtained by metagenomic sequencing, of which 33 genomes were unique to the anaerobic ammonium oxidizing system of the experimental group. These 33 genomes could only be detected in the experimental group at different salinity periods (salinity 1%, 2%, 2.5%, 3%, 3.5%, and 4%), but their abundance varied in different salinity periods.

[0059] Species annotation of metagenomic sequencing results at 4% salinity was performed to identify salt-tolerant bacteria from salt lakes that may play a primary symbiotic role with anaerobic ammonium-oxidizing bacteria. At the phylum level, these unique genomes were found to primarily belong to 11 phyla: Bacteroidota, Bdellovibrionota, Chloroflexota, Desulfobacterota_B, Gemmatimonadota, Hinthialibacterota, Hydrogenedentota, JAGRBM01, Patescibacteria, Planctomycetota, and Pseudomonadota. At the genus level, 20 taxa were annotated, although some genomes (10) were not annotated at the genus level. Thirteen genomes could be annotated to species, while the remaining 20 genomes were not annotated at the species level. Then, based on KEGG annotation analysis, we looked for complete pathways for synthesizing compatible solutes in these identified bacteria. We found that the proportion of microorganisms with complete pathways for synthesizing compatible solutes in the anaerobic ammonia oxidation system of the experimental group in the total bacterial community was glutamate (85.8%), proline (49.3%), trehalose (46.4%), sorbitol (9.5%), glycine betaine (6.9%), tetrahydropyrimidine (5.8%), and mannose (1.1%). Of the 33 unique genomes, 94% (31) had complete pathways for synthesizing at least one compatible solute, and 20 genomes (60.6%) had complete pathways for synthesizing ≥3 compatible solutes. The species annotation results and pathway analysis results are shown in the table below:

[0060] The relative abundance of unique genomes at the genus level in the anaerobic ammonium oxidation system of the experimental group at a salinity of 4% was analyzed. The results are shown in the table below (only the bacterial genera that can be annotated to the genus level are shown):

[0061] The above results indicate that salt lake halotolerant bacteria include a variety of bacteria with complete compatible solute synthesis pathways. These bacteria may improve the salt tolerance and growth advantages of anaerobic ammonium oxidizers (ANAOMOXs) through the secretion of multiple compatible solutes, forming a symbiotic colony of salt lake halotolerant bacteria and ANAOMOXs with advantages in energy metabolism and growth competition. Among these, the relative abundance of Zeimonas, SURF-28, Promineifilum, and BOKV01 was higher in a higher salinity (4%) environment, suggesting that these bacteria may play a major symbiotic role with ANAOMOXs.

[0062] In summary, this example employs a bioaugmentation strategy, introducing salt lake halotolerant bacteria into the anaerobic ammonium oxidation (ANAMMOX) system to establish a symbiotic system between salt lake halotolerant bacteria and ANAMMOX bacteria. This synergistic effect can optimize the ANAMMOX system's bacterial structure and function, improving its salt tolerance and stability without the need for a continuous supply of exogenous compatible solutes. The acclimated ANAMMOX system of this example can be directly used for subsequent high-salinity wastewater treatment.

[0063] The above content is a further detailed description of the present application in conjunction with specific implementation methods, and the specific implementation of the present application cannot be considered to be limited to these descriptions. For ordinary technicians in the technical field to which the present application belongs, several simple deductions or substitutions can be made without departing from the concept of the present application.

Claims

1. A symbiotic bacterial community of salt lake salt-tolerant bacteria and anaerobic ammonia-oxidizing bacteria, characterized in that: The anaerobic ammonium oxidizing bacteria are freshwater bacteria, including Ca. Broadia and Ca. Kuenenia At least one of .

2. The symbiotic bacterial community according to claim 1, characterized in that The symbiotic bacterial community is mixed bacterial powder, mixed bacterial culture or activated sludge.

3. The symbiotic bacterial community according to claim 1, characterized in that The biomass ratio of the anaerobic ammonia oxidizing bacteria and the salt lake salt-tolerant bacteria is 0.5-2.

4. The symbiotic bacterial community according to claim 1, characterized in that The anaerobic ammonium oxidizing bacteria include at least Ca. Kuenenia .

5. The symbiotic bacterial community according to claim 1, wherein The salt lake salt-tolerant bacteria include the following genera: Zeimonas, SURF-28, Promineifilum and BOKV01.

6. The symbiotic bacterial community according to claim 5, characterized in that Among the salt lake halotolerant bacteria, based on relative abundance, the salt lake halotolerant bacteria include 40% to 55% of Zeimonas, 8% to 15% of SURF-28, 5% to 10% of Promineifilum and 4% to 8% of BOKV01.

7. The symbiotic bacterial community according to claim 5 or 6, characterized in that The salt lake salt-tolerant bacteria also include at least one or more of the following genera: JACQPU01, Vreelandella, BM516, Nitrosomonas, Flexicrinis, Denitrolinea, JAJVHZ01, JAABRB01, UTPRO1, JAHDWY01, Pseudorhodoplanes, UBA2336, DSQQ01, Brocadia, JABLXU01, and Sulfurivermis.

8. Use of the symbiotic bacterial consortium according to any one of claims 1 to 7 in wastewater denitrification treatment.

9. The use according to claim 8, characterized in that The salt content of the wastewater calculated as sodium chloride is ≥1%; and / or the salt content of the wastewater calculated as sodium chloride is 3.5%~4%.

10. The use according to claim 8, characterized in that The biomass of the symbiotic bacteria in the wastewater is 2.5 g / L to 5 g / L.

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