JP4610374B2 - Novel microorganism, wastewater treatment method and wastewater treatment apparatus using the novel microorganism - Google Patents

Description

  The present invention relates to a novel microorganism that generates nitrogen gas using, for example, nitrate ions contained in wastewater as a substrate, and further relates to a wastewater treatment method and a wastewater treatment apparatus using the novel microorganism.

  For example, nitrate ions contained in wastewater are one of the causes of eutrophication problems in the water environment, and are substances that are subject to total amount regulations in closed sea areas. The nitrate ions contained in the water environment are generally reduced to nitrogen gas and removed by denitrification by microorganisms. More specifically, ammonium ions contained in waste water or the like are oxidized to nitrate ions and / or nitrite ions in an aerobic state, and subsequently reduced to nitrogen gas in an anaerobic state.

  However, conventionally, most research reports on microorganisms having denitrification ability are those by microorganisms that grow at room temperature of 20-30 ° C., and only microorganisms that use nitrite ions as substrates at high temperature conditions have been reported ( Non-patent document 1). Under high temperature conditions, the solubility of nitrogen gas, which is a gas, in water is reduced, so that a more effective denitrification reaction is expected. In the research of Non-Patent Document 1, 1 mmol (50 ppm) of nitrous acid was consumed in 10-20 hours of cultivation using Bacillus genus bacteria, which are thermophilic bacteria, and 0.4-0.5 mmol of nitrous oxide was produced (almost quantitative). Reaction). The culture temperature is 60 ° C.

  However, since nitrous acid as a substrate in this research is an intermediate product generated from nitric acid, a sufficient effect cannot be expected with conventional microorganisms for the purpose of denitrification of wastewater and the like. That is, at present, there is no efficient denitrification technique under high temperature conditions.

N. Gokce et al., Applied and Environmental Microbiology, Vol.55, No.4, p.1023-1025, 1989

  Therefore, in view of the above situation, the present invention is a novel microorganism capable of performing denitrification using nitrate ions contained in wastewater or the like as a substrate, and in particular, can be denitrified under moderately high temperature conditions. It aims at providing a novel microorganism, and also aims at providing the waste-water-treatment apparatus and waste-water-treatment method using the said microorganism.

  In order to achieve the above-mentioned object, the present inventors have conducted intensive studies to isolate and identify microorganisms having the desired characteristics using soil, rivers, or activated sludge as a separation source, and as a result, they are not classified as conventionally known microorganisms. Several new microorganisms could be isolated and identified. The present invention has been made based on the knowledge that denitrification can be performed using nitrate ions of these novel microorganisms as substrates. The new microorganisms isolated and identified are all considered to belong to the same new species, and are not classified into conventionally known species.

  The novel microorganism according to the present invention belongs to the genus Geobacillus, grows at 37 to 60 ° C., and has the ability to generate nitrogen gas using nitrate ions as a substrate. Among the novel microorganisms isolated and identified by the present inventors, TDN-01, TDN-02 and TDN-03 have the mycological properties described in any of Tables 1 to 3 below.

本発明者らが単離、同定した複数の新規微生物のうち、５種類の微生物（それぞれ、TDN-01、TDN-02、TDN-03、TDN-04及びTDN-05と命名した）に関して16S rRNAをコードする遺伝子（以下、16S rDNAと称する）の塩基配列を決定した。TDN-01の16S rDNAの塩基配列を配列番号１に示し、TDN-02の16S rDNAの塩基配列を配列番号２に示し、TDN-03の16S rDNAの塩基配列を配列番号３に示し、TDN-04の16S rDNAの塩基配列を配列番号４に示し、TDN-05の16S rDNAの塩基配列を配列番号５に示す。

Among a plurality of novel microorganisms isolated and identified by the present inventors, 16S rRNA for 5 types of microorganisms (named TDN-01, TDN-02, TDN-03, TDN-04 and TDN-05, respectively) The base sequence of the gene encoding the gene (hereinafter referred to as 16S rDNA) was determined. The base sequence of 16S rDNA of TDN-01 is shown in SEQ ID NO: 1, the base sequence of 16S rDNA of TDN-02 is shown in SEQ ID NO: 2, the base sequence of 16S rDNA of TDN-03 is shown in SEQ ID NO: 3, and TDN- The base sequence of 16S rDNA of 04 is shown in SEQ ID NO: 4, and the base sequence of 16S rDNA of TDN-05 is shown in SEQ ID NO: 5.

  When homology search was performed using the database (GenBank / DDBJ / EMBL) and homology search software (BLAST) based on these nucleotide sequences shown in SEQ ID NOs: 1 to 5, in all of SEQ ID NOs: 1 to 5, “Geobacillus kaue strain BGSC It shows the highest homology (97-99%) with the nucleotide sequence registered as “W9A78 16S ribosomal RNA gene”, followed by the high homology with the nucleotide sequence registered as “Geobacillus uzenensis strain BGSC 92A2 16S ribosomal RNA gene” (97 ~ 99%). However, there were no conventional microorganisms showing homology of 99.8% or more in all the base sequences shown in SEQ ID NOs: 1 to 5.

  The present invention is based on the above bacteriological properties in light of the Bergey's Manual of Systematic Bacteriology, Volume 2 (1986), and based on the results of 16S rDNA sequence analysis. When the taxonomic position of the new microorganisms was examined, these new microorganisms were classified into new species belonging to the genus Geobacillus.

  Among the new microorganisms belonging to the new species, TDN-01, TDN-02 and TDN-03 are registered with the National Institute of Advanced Industrial Science and Technology, Patent Biological Deposit Center (Chuo 1-1-1 Higashi 1-1-1 Tsukuba City, Ibaraki Prefecture, 305-8566) ) On February 18, 2005 as deposit numbers FERM AP-20412, FERM AP-20413 and FERM AP-20414, respectively.

In particular, the microorganism according to the present invention has the ability to generate N ₂ gas using nitrate ions as a substrate under moderately high temperature conditions. Here, the moderately high temperature condition means that the waste water temperature to be treated is 37 to 60 ° C, preferably 50 to 60 ° C.

  On the other hand, the wastewater treatment method and wastewater treatment apparatus according to the present invention remove nitrate ions contained in wastewater under moderately high temperature conditions using the microorganisms according to the present invention described above. The wastewater treatment method and the wastewater treatment apparatus according to the present invention can remove nitrate ions, which could not be removed by the conventional method using denitrifying bacteria, under moderately high temperature conditions by using the above-described microorganisms. . In addition, the wastewater treatment method and the wastewater treatment apparatus according to the present invention can treat wastewater of moderately high temperature conditions with the above-described microorganisms.

  ADVANTAGE OF THE INVENTION According to this invention, the novel microorganisms which can denitrify using the nitrate ion contained in waste water etc. as a substrate can be provided. In particular, the novel microorganism according to the present invention can be denitrified using nitrate ions as a substrate even under moderately high temperature conditions. By utilizing the novel microorganism according to the present invention, it is possible to provide a wastewater treatment method and a wastewater treatment apparatus that can remove nitrogen components contained in wastewater and the like. In these wastewater treatment methods and wastewater treatment apparatuses, the temperature of the wastewater to be treated can be set to a moderately high temperature condition, so that it is possible to achieve excellent denitrification efficiency and cost reduction.

Hereinafter, the present invention will be described in detail.
The novel microorganism according to the present invention belongs to the genus Geobacillus and has an ability to generate N ₂ gas using nitrate ions as a substrate. The novel microorganism according to the present invention is classified into a new species of the genus Geobacillus, which is different from Geobacillus kaue and Geobacillus uzenensis. The novel microorganism according to the present invention exhibits the ability to generate N ₂ gas using nitrate ions as a substrate under moderately high temperature conditions, that is, the temperature of the solution to be treated is 37 to 60 ° C., preferably 50 to 60 ° C. be able to.

  Microorganisms belonging to the new species can be isolated from the environment such as activated sludge, fields, river water, and bottom soil of anaerobic layers in sewage treatment plants. As a specific method, first, samples collected from the above various environments are cultured under moderately high temperature conditions, and selection is made based on the presence or absence of denitrification ability. Here, the sample is preferably stored under anaerobic conditions. Moreover, when examining the denitrification ability of the target microorganism, a conventionally known method, that is, a method of monitoring a decrease in the concentration of nitric acid and nitrous acid in the culture solution can be applied. For example, Griess-romijn (GR) reagent can be used for detection of nitric acid and nitrous acid. The GR reagent includes Griess-romijn nitrate reagent and Griess-romijn nitrite reagent, which can detect nitric acid and nitrous acid, respectively. More specifically, the culture solution is centrifuged (for example, 15000 rpm, 15 minutes, room temperature), the supernatant is collected in a test tube, a small amount of GR nitrate reagent or GR nitrite reagent is added and mixed, and then left to stand for color. By observing this change, nitrate ions or nitrite ions in the culture medium can be detected. Depending on the amount of nitrate and nitrite ions, the solution turns from clear to light pink and dark red.

  By using the microorganism according to the present invention, a novel wastewater treatment method and wastewater treatment apparatus can be constructed. That is, as long as the waste water to be treated is denitrified using the above-mentioned microorganisms, all are included in the waste water treatment method and the waste water treatment apparatus according to the present invention regardless of differences in treatment steps and apparatus configurations.

  As a wastewater treatment apparatus, for example, as shown in FIG. 1, a denitrification tank 1 that performs denitrification by microorganisms according to the present invention, a nitrification tank 2, and a cogeneration apparatus 3 that supplies heat to the denitrification tank 1 And an aeration tank 4 for removing nitrogen gas generated as a result of denitrification in the denitrification tank 1. The cogeneration apparatus 3 is a system that extracts a plurality of energies from one energy, and examples thereof include an engine, a turbine, and / or a fuel cell (FC). These engine, turbine, and / or fuel cell (FC) cogeneration apparatus 3 generates thermal energy by exhaust heat recovery in addition to electrical energy. The wastewater treatment apparatus shown in FIG. 1 is configured to supply the thermal energy generated in the cogeneration apparatus 3 to the waste liquid in the denitrification tank 1. In addition, when the amount of heat from the cogeneration is less than the amount of heat for heating the denitrification tank, it is also possible to perform the shortage heating with an attached boiler or the like.

  In the wastewater treatment apparatus shown in FIG. 1, first, wastewater to be treated is supplied to the nitrification tank 2, and then air is introduced into the wastewater in the nitrification tank 2 to nitrify ammonium ions in the wastewater into nitrate ions. . Specifically, in the nitrification tank 2, the nitrification reaction proceeds by microorganisms having nitrification ability under aerobic conditions. The microorganism having nitrification ability is not particularly limited as long as it is a nitrifying bacterium capable of digesting ammoniacal nitrogen into nitrate ions. As an example, the oxidation of ammonia to nitrous acid and the oxidation of nitrous acid to nitric acid can be performed using Nitrosomonas bacteria, Nitrobacter bacteria, Nitrococcus bacteria, etc. (Edited by Toshio Omori, Environmental Microbiology) , P. 25-28, Shosodo, 2000). Waste water after nitrifying ammonium ions into nitrate ions is supplied from the nitrification tank 2 to the denitrification tank 1.

  Next, in the denitrification tank 1, the denitrification reaction using nitrate ions contained in the wastewater as a substrate is advanced by the above-described novel microorganisms. In the wastewater treatment apparatus shown in FIG. 1, heat energy from the cogeneration apparatus 3 using city gas or the like as fuel is supplied to the denitrification tank 1, and the waste liquid in the denitrification tank 1 is set to a medium high temperature condition. In the denitrification tank 1, a denitrification reaction can be performed using nitrate ions contained in wastewater as a substrate under moderately high temperature conditions.

  In the wastewater treatment apparatus according to the present invention, since the denitrification reaction can be performed under a higher temperature condition than in the prior art, an excellent reaction efficiency can be achieved. Therefore, the wastewater treatment apparatus according to the present invention can reduce the size of the denitrification tank 1 and can reduce the cost. Furthermore, since the solubility of the gas component decreases at a high temperature, nitrogen gas generated as a result of the denitrification reaction can be efficiently removed.

  The wastewater treatment apparatus according to the present invention is not limited to the configuration shown in FIG. 1, and for example, as shown in FIG. 2, the heat energy from the cogeneration apparatus 3 is also given to the air introduced into the nitrification tank 2. You may have the structure. Also in the wastewater treatment apparatus shown in FIG. 2, the waste liquid in the nitrification tank 2 can be brought to a medium high temperature condition by the thermal energy from the cogeneration apparatus 3. As a result, in the waste liquid treatment apparatus shown in FIG. 2, similarly, in the denitrification tank 1, the denitrification reaction can be executed using nitrate ions contained in the wastewater as a substrate under moderately high temperature conditions. The waste liquid treatment apparatus shown in FIG. 2 can suppress the temperature drop of the nitrification tank 2 because it warms the air, so that the reaction efficiency of the nitrification tank 2 can be increased and the temperature drop of the inflow portion of the denitrification tank 1 can be achieved. Can be suppressed.

  In addition, the waste liquid treatment apparatus according to the present invention is not limited to the one having the cogeneration apparatus 3 as a means for controlling the temperature of the waste liquid. For example, as shown in FIGS. 3 and 4, the boiler is a means for controlling the temperature of the waste liquid. 5 may be sufficient. Similarly, in the waste liquid treatment apparatus shown in FIG. 3 or 4, in the denitrification tank 1, the denitrification reaction can be performed using nitrate ions contained in the wastewater as a substrate under moderately high temperature conditions.

  Furthermore, when the waste liquid treatment apparatus according to the present invention is used for the treatment of waste liquid (digestion residue liquid) of methane fermentation, it is desirable to take a configuration as shown in FIGS. A methane fermentation tank 6 and a solid-liquid separator 7 connected to the methane fermentation tank 6 are further provided, and biogas such as methane generated in the methane fermentation tank 6 is supplied to the cogeneration apparatus 3 or the boiler 5. The waste liquid (digested liquid residue) after methane fermentation in the methane fermentation tank 6 is processed in the solid-liquid separator 7, and the separated liquid is supplied to the nitrification tank 2. In the waste liquid treatment apparatus shown in FIGS. 5 and 6, a storage tank may be provided before the solid-liquid separation apparatus 7. Moreover, the solid-liquid separation apparatus 7 can also be abbreviate | omitted as needed. In the waste liquid treatment apparatus shown in FIGS. 5 and 6, at least a part of the fuel necessary for driving the cogeneration apparatus 3 or the boiler 5 can be covered with biogas generated in the methane fermentation tank 6. In addition, as fuel required for the drive of the cogeneration apparatus 3 or the boiler 5, in addition to the biogas produced | generated with the methane fermentation tank 6, you may supply city gas etc. in mixture. Similarly, in the waste liquid treatment apparatus shown in FIGS. 5 and 6, in the denitrification tank 1, the denitrification reaction can be performed using nitrate ions contained in the wastewater as a substrate under moderately high temperature conditions. In methane fermentation, since the fermentation is performed at a medium temperature to a high temperature (35 to 60 ° C.), the temperature of the waste water (digested liquid residue) is high. In the waste liquid treatment apparatus shown in FIGS. Compared with the apparatus, the amount of heat to be supplied to the denitrification tank 1 is reduced. The apparatus shown in FIGS. 5 and 6 may heat the air supplied to the nitrification tank 2 as in FIGS. 2 and 4.

  The wastewater treatment apparatus and the wastewater treatment method described above can be a microbial process performed in an open system (for a closed system such as a laboratory). In general, when a microbial process is performed in an open system, many microorganisms are always mixed from the surrounding environment, and a microbial ecosystem corresponding to the environment in the wastewater treatment apparatus is formed. In addition, this microbial ecosystem continues to change gradually while being relatively stable.

  In the wastewater treatment apparatus and the wastewater treatment method according to the present invention, the treatment is performed particularly under moderately high temperature conditions such that the temperature in the denitrification tank 1 is 37 to 60 ° C, preferably 50 to 60 ° C. For this reason, in the wastewater treatment apparatus and the wastewater treatment method according to the present invention, most of the microorganisms mixed from the surrounding environment cannot grow, and even in an open system, it is possible to realize a process close to pure culture. is there.

  Moreover, in the waste water treatment apparatus and waste water treatment method according to the present invention, the temperature in the denitrification tank 1 is 37 to 60 ° C, preferably 50 to 60 ° C. The solubility of gas in water in 1 can be lowered. Therefore, in denitrification performed under anaerobic conditions, a decrease in the dissolved oxygen concentration in the denitrification tank 1 can be expected, and it becomes easier to create anaerobic conditions. Further, since the solubility of nitrogen gas generated in the denitrification tank 1 is lower than that at room temperature, the reaction equilibrium is more inclined to generate nitrogen gas by releasing nitrogen gas, which is a reactive organism, out of the system. It will be.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example, the technical scope of this invention is not limited to a following example.

[Example 1] Isolation and identification of novel microorganisms
A separation source culture conditions microorganism, attempted activated sludge anaerobic layer of sewage treatment plants, Saitama city fields, the isolation of the denitrifying bacteria according enrichment culture using river water-subsoil like. The microorganism separation sources used are as follows.
Soil: About 50 field farm soils in Saitama City River water / sediment: Shiba River and 6 domestic drainage channels Activated sludge: Anaerobic tank in the western second sewage treatment plant

  The soil was sealed in a plastic bag with a chuck immediately after collection, and used within 2-3 days. River water, bottom soil, and activated sludge were collected to the limit of capacity using PET bottles, etc., and kept away from air as much as possible. Further, a small amount of ascorbic acid was added and used during 2-3 days or stored refrigerated until use. Since denitrification occurs under anaerobic conditions, care was taken not to touch oxygen during sample collection and storage.

  The composition of the medium is shown in Table 4. The denitrification reaction requires a carbon source for the growth of microorganisms. In this experiment, succinic acid was used as a carbon source.

  A 500 ml Erlenmeyer flask with a branch or a 100 ml brown vial was used for obtaining microorganisms. In a 500 ml Erlenmeyer flask with a branch, 400 ml of medium was prepared and dispensed, and then a microorganism source was added. The cells were sealed with a butyl rubber stopper or the like and cultured in an anaerobic state by replacing the gas phase with argon gas. The culture was performed under shaking at 120 rpm, 30 ° C. or 60 ° C. for 2 days to 1 week. For the culture solution in which the growth of the cells was observed, nitrate ions and nitrite ions were detected with Griess-romijn reagent. The sample in which the denitrification reaction was observed was transferred to a new medium, and cultured again for 2 days to 1 week.

  In a 100 ml brown vial, 70 ml of medium was prepared, and a Durham tube and a microorganism source were added. When the Durham tube is inserted, gas produced by microorganisms can be collected and observed. It was sealed with a butyl rubber stopper or the like, and the gas phase was replaced with argon gas to make it anaerobic. Static culture was performed for 2 days to 1 week in a thermostatic bath at 30 ° C or 60 ° C. For the culture solution in which the growth of the cells was observed, nitrate ions and nitrite ions were detected with Griess-romijn reagent. The sample in which the denitrification reaction was observed was transferred to a new medium, and cultured again for 2 days to 1 week.

Analytical method Griess-romijn (GR) reagent was used to detect nitrate and nitrite ions. The GR reagent includes Griess-romijn nitrate reagent and Griess-romijn nitrite reagent, which are used to detect nitric acid and nitrous acid, respectively. Depending on the amount of each ion, the color changes from transparent to light peach and dark red. The culture solution was centrifuged (15000 rpm, 15 minutes, room temperature), and the supernatant was collected in a test tube, mixed with a small amount of GR nitrate reagent or GR nitrite reagent, and allowed to stand to observe the color change.

Experimental result
Nitric acid and nitrous acid were detected with the GR reagent for the samples in which cell growth was observed at 30 ° C. Since nitric acid is added to the medium, nitric acid decreases as denitrification proceeds. Nitrous acid is also detected in reactions where nitric acid is only reduced to nitrous acid. When denitrification progresses, nitric acid (-) and nitrous acid (-) are observed. The results are summarized in Table 5.

  As can be seen from Table 5, denitrification ability was observed in the samples No. 2-4, and strong denitrification ability was particularly expected for No. 2 and No. 4.

  Next, samples in which cell growth was observed at 60 ° C. and generation of gas were also examined. That is, nitric acid and nitrous acid were detected with the GR reagent for a sample in which gas was collected in the Durham tube or bubbles were generated on the surface of the medium. The results are shown in Table 6.

  As can be seen from Table 6, the sample No. 5-7 was found to have a denitrification ability, and particularly No. 5 was expected to have a strong denitrification ability. Moreover, although No.2-4 was a little weak, there was a possibility of performing denitrification.

  Microorganisms were isolated using a dilution plate culture method. A plate solid medium was prepared by adding 7% of Gellum gum to the BM medium. The mixed microorganism system in which denitrification reaction was confirmed was appropriately diluted with sterilized water, smeared on a solid plate medium, and then anaerobically cultured at 60 ° C.

  Next, microorganisms having denitrification ability were isolated from the samples in which denitrification ability was recognized as follows. Specifically, first, a solid plate medium was observed for several days, and colony formation (a group of microorganisms thought to have grown from a single cell. Usually observed as a circular shape with a diameter of several millimeters) was observed. Colonies were sequentially collected from the seeds, inoculated into a fresh medium, and used as storage samples.

  The stored sample was again subjected to liquid culture, and the presence or absence of a denitrification reaction at 60 ° C. was confirmed using gas generation from nitric acid as an indicator. The sample in which the denitrification reaction was confirmed was again diluted appropriately with sterilized water, smeared on a solid plate medium, and then anaerobically cultured at 60 ° C. It was confirmed by macroscopic observation that it was a single bacterium, colonies were collected again, inoculated into a fresh medium, and used as a preservation sample. This series of operations was repeated several times to obtain a pure microbial sample with stable denitrification activity.

  From the above experiments, five strains of microorganisms that grow stably at a temperature of 60 ° C. and have the ability to generate nitrogen gas from nitric acid were obtained. Each was changed from TDN-01 strain to TDN-05 strain. Three strains, TDN-01, TDN-02 and TDN-03, which have stable denitrification activity and are relatively high, are the National Institute of Advanced Industrial Science and Technology patent biological deposit center (Tsukuba, Ibaraki, 305-8566) Deposited on February 18, 2005 as receipt numbers FERM AP-20412, FERM AP-20413, and FERM AP-20414, respectively, on the city center 1-1-1 No. 6).

In addition, genomic DNA of TDN-05 strain was extracted from these TDN-01 strains, and the base sequence of 16S-rDNA was determined. The 16S-rDNA base sequence determination method is based on the general dideoxy method described in p180-183 and p239-244 of "Microbiology Experimental Method (Sugiyama et al., Kodansha, 1999)". It was. In this method, a 16S-rDNA of a target microorganism is amplified by polymerase chain reaction (PCR), a DNA fragment having a random length is obtained by addition of dideoxynucleotide triphosphate, and this is sequenced. .
The primers used for PCR are shown in Table 7.

  The reaction solution containing the above primer and genomic DNA was treated at 96 ° C. for 30 seconds, followed by 25 cycles of 96 ° C. for 30 seconds, 50 ° C. for 5 seconds and 60 ° C. for 2 minutes, and then at 60 ° C. Treated for 2 minutes. After the reaction, the reaction solution was stored at 4 ° C. The obtained DNA fragment was sequenced with an automatic sequencer (ABI PRISM ™ 310NT Genetic Analyzer). Sequence data using the above-mentioned plurality of primers were connected to obtain data of about 500 base pairs (10th to 500th positions from the 5 'side in 16S-rDNA of E. coli).

  The base sequence of 16S rDNA of TDN-01 strain determined as described above is shown in SEQ ID NO: 1, the base sequence of 16S rDNA of TDN-02 strain is shown in SEQ ID NO: 2, and the base sequence of 16S rDNA of TDN-03 strain is shown. The base sequence of 16S rDNA of TDN-04 strain is shown in SEQ ID NO: 4, and the base sequence of 16S rDNA of TDN-05 strain is shown in SEQ ID NO: 5.

  A homology search using the database (GenBank / DDBJ / EMBL) and homology search software (BLAST) based on these nucleotide sequences shown in SEQ ID NOs: 1 to 5, both of which are 97-99% homologous to the genus Geobasillus. It was judged to be related. The homology between each strain was calculated based on the partial nucleotide sequence of 16S-rDNA from TDN-01 strain to TDN-05 strain, and showed 96-99% homology. FIG. 7 shows the result of creating a phylogenetic tree with related species. From the phylogenetic tree, the TDN-01, TDN-02, and TDN-03 strains clearly form another group (cluster) with other Geobasillus bacteria, and other Geobasillus bacteria clusters. The branch of is close to the root (where each branch becomes one). This indicates that the TDN-01, TDN-02 and TDN-03 strains diverged early in terms of molecular evolution. Therefore, it was concluded that these TDN-01 strain, TDN-02 strain and TDN-03 strain are new genera belonging to the genus Geobasillus. In addition, it is generally considered that 16S-rDNA having a homology of 99.8% or more is the same species (edited by Sugiyama et al., New Microbiology Experimental Method, p241-242, Kodansha Scientific, 1999 Year).

It is a block diagram which shows an example of the waste water treatment apparatus to which this invention is applied. It is a block diagram which shows an example of the waste water treatment apparatus to which this invention is applied. It is a block diagram which shows an example of the waste water treatment apparatus to which this invention is applied. It is a block diagram which shows an example of the waste water treatment apparatus to which this invention is applied. It is a block diagram which shows an example of the waste water treatment apparatus to which this invention is applied. It is a block diagram which shows an example of the waste water treatment apparatus to which this invention is applied. It is a phylogenetic tree including TDN-01 strain, TDN-02 strain, TDN-03 strain and related species.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Denitrification tank, 2 ... Nitrification tank, 3 ... Cogeneration apparatus, 4 ... Aeration tank, 5 ... Boiler, 6 ... Methane fermentation tank, 7 ... Solid-liquid separation apparatus

Claims (9)

It belongs to the genus Geobacillus and has the ability to generate N ₂ gas using nitrate ions as a substrate . Microorganisms having mycological properties described in any of Tables 1 to 3 below .

The microorganism according to claim 1, which has an ability to produce N ₂ gas using nitrate ions as a substrate under conditions of 37 to 60 ° C. A wastewater treatment method comprising a step of bringing the microorganism according to claim 1 or 2 into contact with wastewater containing nitrate ions. The wastewater treatment method according to claim 3 , wherein the wastewater is set to 37 to 60 ° C. The wastewater treatment method according to claim 3 , further comprising the step of removing nitrogen gas contained in the waste liquid after contacting the microorganism. A wastewater treatment apparatus comprising a denitrification tank for bringing the microorganism according to claim 1 or 2 into contact with wastewater containing nitrate ions. The wastewater treatment apparatus according to claim 6 , further comprising temperature control means for controlling the temperature of the wastewater to a desired temperature. The waste water treatment apparatus according to claim 7 , wherein the temperature control means controls the temperature of waste water in the denitrification tank to 37 to 60 ° C. The waste water treatment apparatus according to claim 7 , wherein the temperature control means controls the temperature in the denitrification tank and / or the nitrification tank connected to the denitrification tank.

Images