Dehalogenation bacillus with dichloromethane anaerobic degradation capability and application of dehalogenation bacillus

Abstract

The invention relates to the field of environmental pollution remediation, in particular to a dehalogenation bacillus strain with dichloromethane anaerobic degradation capacity and application of the dehalogenation bacillus strain. The strain is a dehalogenator strain DCM (Dehalobacter sp.) which is preserved in the China General Microbiological Culture Collection Center (CGMCC) on November 30, 2021, the preservation address is Institute of Microbiology, Chinese Academy of Sciences, No.3, No.1 Yard, Beichen West Road, Chaoyang District, Beijing, and the preservation number is CGMCC No.24007. The invention further discloses a preparation method of the dehalogenator strain. The novel dehalogenation bacillus strain DCM provided by the invention is separated and purified from polluted river sediment, the strain is gram-positive, rod-shaped and smooth in surface, the length of the strain is 1-2 mu m, and the diameter is 0.3-0.5 mu m. The strain can completely convert 160 micromoles of dichloromethane into formate and acetate within 7 days in an anaerobic inorganic salt culture medium, the degradation rate is as high as 32 micromoles D <-1 >, and it is indicated that the strain can efficiently degrade dichloromethane pollutants and has wide application prospects in environmental sewage treatment and environmental remediation.

Description

Technical Field

[0001] The invention discloses the field of environmental pollution restoration, and more specifically relates to a dehalogenating bacterium capable of anaerobic degradation of dichloromethane and application thereof. Background Art

[0002] Dichloromethane (DCM) is an important volatile halogenated hydrocarbon that is widely used in industrial production, mainly in adhesives, pesticides, metal degreasers, paint strippers, etc. With the continuous acceleration of urbanization and industrialization, the demand for dichloromethane is increasing. The large-scale use of dichloromethane leads to its entry into the environment through wastewater, gas and solid waste, especially into groundwater, soil and atmosphere. The environmental concentration of dichloromethane is often high in industrial areas, landfills and around chemical plants. This compound is volatile, has high water solubility and low adsorption capacity, making it highly mobile in the environment. In addition, dichloromethane is potentially toxic to humans and ecosystems. Short-term exposure can cause neurotoxicity, respiratory irritation and skin damage, while long-term exposure may lead to hepatotoxicity and carcinogenic risks. Therefore, the International Agency for Research on Cancer (IARC) classifies it as a possible human carcinogen (Group 2B). Dichloromethane is difficult to degrade naturally in the environment and has environmental persistence. In recent years, with the enhancement of environmental awareness and the implementation of relevant laws and regulations, environmental control of dichloromethane during production and use has received more and more attention. At present, dichloromethane has been included in the first batch of "List of New Pollutants under Key Control (2023 Edition)" issued by the Ministry of Ecology and Environment of my country, and has also been included in the list of toxic and harmful air pollutants and the list of toxic and harmful water pollutants. It is a new pollutant that needs to be controlled.

[0003] Traditional physical and chemical remediation technologies are costly and prone to secondary pollution. In comparison, bioremediation technology uses microorganisms to convert dichloromethane into low-toxic or non-toxic substances, which is a green, economical and efficient solution. So far, the dichloromethane aerobic degrading bacteria reported successively are mainly from microbial genera such as Hyphomicrobium, Albibacter, Ancylobacter, Bacillus, Gottschalkia, Lysinobacillus, Paracoccus, Methylophilus, Methylopila, and Methylobacterium. However, even in micro-oxic and anoxic environments, a large number of dichloromethane pollutants are distributed, but the anaerobic microbial population that can metabolize dichloromethane is very small. For example, the Dehalobacteriumformicoaceticum DMC strain reported in 1996 is currently the only pure culture that can anaerobically degrade dichloromethane. As early as 2012, some culture fluids highly enriched with Dehalobacter microorganisms were believed to be able to anaerobically metabolize dichloromethane, but due to the limitations of separation technology, pure cultures of Dehalobacter have not yet been obtained. This directly leads to problems such as low efficiency of anaerobic remediation of dichloromethane, insufficient adaptability, limited technology research and development, increased ecological risks, and over-reliance on other remediation methods. Therefore, obtaining a biomaterial that can anaerobically degrade dichloromethane, especially a new type of Dehalobacter, is a major breakthrough in the field of environmental bioremediation. Summary of the invention

[0004] In view of the above, the present invention aims to provide a Dehalogenobacter strain having the ability to anaerobically degrade dichloromethane and its application.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A strain of Dehalobacter sp. with the ability to anaerobically degrade dichloromethane, the strain is Dehalobacter sp. DCM (Dehalobacter sp.), which was deposited in the General Microbiology Center of China Culture Collection on November 30, 2021. The deposit address is the Institute of Microbiology, Chinese Academy of Sciences, No. 3, Building 1, Beichen West Road, Chaoyang District, Beijing, and the deposit number is CGMCC No. 24007.

[0007] The bacteria are rod-shaped, Gram-positive, 1-2 μm in length, and 0.3-0.5 μm in diameter.

[0008] An application of the Dehalogenating Bacterium, and application of the strain in degrading dichloromethane pollutants in the environment.

[0009] The strain is used to degrade dichloromethane pollutants in the environment under anaerobic conditions.

[0010] The environment is water, sediment or soil.

[0011] A preparation for degrading dichloromethane pollutants, the preparation containing the Dehalogenobacter strain DCM.

[0012] The preparation contains the cell culture, cell culture concentrate, cell culture filtrate or culture suspension of the strain.

[0013] A method for degrading dichloromethane pollutants comprises inoculating the strain or the bacterial agent into an environmental sample to be treated, adding sodium sulfide with a final concentration of 0.05 mM as a deoxidizer to the environmental sample, and thereby achieving anaerobic degradation of dichloromethane in the environmental sample.

[0014] The inoculation amount of the strain or bacterial agent is 0.1% (w / v).

[0015] Compared with the prior art, the present invention has the following advantages and effects:

[0016] The invention provides a Dehalobacter sp. DCM strain capable of degrading dichloromethane. A gas chromatograph is used to perform quantitative analysis on dichloromethane, and it is found that the Dehalobacter sp. DCM strain has the ability to quickly consume DCM. A liquid chromatograph is used to perform qualitative and quantitative analysis on degradation products of DCM, and it is found that the degradation products are acetic acid and formic acid, which proves that the strain has the ability to efficiently degrade dichloromethane pollutants into non-toxic small-molecule organic acids, and has the potential to be applied to groundwater, soil and other environments to realize biodegradation of dichloromethane. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a comparison chart of the degradation rates of dichloromethane by different single bacterial colonies in the examples of the present invention;

[0018] Figure 2 This is a scanning electron microscope image of the novel Dehalobacter sp.DCM strain isolated in the examples of the present invention;

[0019] Figure 3 It is a phylogenetic analysis diagram of the novel Dehalobacter sp.DCM strain of the present invention;

[0020] Figure 4 This is a degradation curve diagram of the novel Dehalobacter sp.DCM strain converting dichloromethane into acetic acid and formic acid in an embodiment of the present invention;

[0021] Figure 5The degradation of dichloromethane by the novel Dehalobacter sp. DCM strain of the present invention at different culture temperatures. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the embodiments and drawings. It should be pointed out that the specific implementation methods described here are only for illustration and explanation of the present invention and are not limited thereto.

[0023] If the specific experimental conditions are not specified in the following embodiments, conventional experimental conditions or methods recommended by the reagent company are generally used. The materials, reagents and equipment used, unless otherwise specified, are conventional materials, reagents and equipment in the art and can be obtained from commercial channels.

[0024] Example 1. Isolation and purification of strains

[0025] (1) Sample collection

[0026] The sediment samples were collected at the Xihe sewage outlet in Shenyang City, Liaoning Province (latitude: 41°39′46″, longitude: 123°6′20″). A high-temperature sterilized shovel was used to dig deep into the river sediment. The removed sediment was quickly sent to a 2L sterile collection bottle, and river water was added to remove the air remaining in the headspace of the bottle. The bottle was covered with a sealed blue rubber stopper, and the collected samples were promptly stored in a 4°C refrigerator, and microbial screening was carried out within one month.

[0027] (2) Construction of artificial microecological system

[0028] First, prepare an anaerobic inorganic salt liquid culture medium according to Table 1, heat and boil it under nitrogen blowing conditions, add 24 mg / L L-cysteine, 48 mg / L Na2S·9H2O and 77 mg / L dithiothreitol (DTT) as reducing agents to remove oxygen from the culture medium, adjust the pH of the culture medium to 7.2 with CO2, and sterilize it with high-temperature steam at 121°C for 30 minutes. Take out 2g of the fresh sediment collected in the above step (1) and inoculate it into a culture bottle containing 10 μL dichloromethane, 0.1mL of complex vitamins and trace elements (Table 1) in 100mL of anaerobic inorganic salt liquid culture medium to prepare an artificial micro-ecological system with dichloromethane as the only carbon source, and place it in a 30°C biochemical incubator to avoid light and culture it statically.

[0029] (3) Enrichment and isolation of dichloromethane-degrading bacteria

[0030] After 30 days of culture, 3 mL of the culture solution was taken as seed solution and transferred to a new 100 mL anaerobic inorganic salt liquid medium according to the inoculum amount. The enrichment culture was carried out for 11 cycles under the same culture conditions and subculture method as in step (2) above to obtain an enriched culture with dichloromethane degradation ability. 1 mL of the suspension was taken from the enriched medium after the 11th subculture and diluted to 10 with a sterile anaerobic inorganic salt medium. -1 Up to 10 -10 Gradual dilution of bacterial solution, 10 -4 Up to 10 -10 The diluted solution was transferred to an inorganic salt semi-solid culture medium with dichloromethane as the sole carbon source, with 3 replicates for each concentration. The culture was placed in an incubator at 30°C and the colony morphology was observed regularly.

[0031] Table 1 Composition and content of anaerobic inorganic salt liquid culture medium, trace elements and composite microorganisms used in the present invention

[0032]

[0033]

[0034] The inorganic salt semi-solid culture medium contains 1% (w / v) agar with a low gelling temperature (Sigma, Germany, item number: A9045), and the other ingredients and preparation method are the same as those of the anaerobic inorganic salt liquid culture medium.

[0035] After half a month of cultivation, single colonies of different morphologies were selected and cultured in 100 mL of anaerobic inorganic salt liquid culture medium containing 10 μL of dichloromethane, and the dichloromethane degradation rate was measured. 1 mL of bacterial solution with the highest degradation rate was selected, and the above gradient dilution purification steps were repeated three times to obtain pure cultures that can degrade dichloromethane and store them in a refrigerator at 4°C.

[0036] Determination of degradation rate: During the biodegradation of dichloromethane, samples were taken regularly and the degradation rate was determined by gas chromatography-flame ionization detector. Degradation rate = (initial content - end point content) / number of culture days.

[0037] Determination of dichloromethane by gas chromatography-flame ionization detector: 1 mL of dichloromethane degradation culture medium was taken to a 20 mL headspace sample bottle and quickly sealed with a cap. Subsequently, the headspace bottle containing the sample was placed on the injection plate of the gas chromatograph for testing. The instrument parameters were as follows: chromatographic column (DB-624, 60 m × 0.32 mm × 1.8 μm); the split ratio of the injection port was 50:1; the injection port temperature was 200 ° C; the column oven temperature program was 60 ° C for 2 min, and then increased to 200 ° C at a heating rate of 25 ° C / min; the carrier gas was 99.999% pure helium, with a flow rate of 3 mL / min; the fuel gas and the combustion aid were hydrogen and synthetic air (purity of 99.999%), respectively, with flow rates of 30 mL / min and 350 mL / min, respectively, and the detector temperature was 300 ° C; the tail gas was nitrogen, with a flow rate of 25 mL / min.

[0038] The results showed that 8 single colonies with different morphologies were picked from the semi-solid culture medium and named as strains A1-A8. A1, A3 and A7 had no degradation activity for dichloromethane, while A2, A4, A5, A6 and A8 could consume dichloromethane at different rates, among which A6 had the highest degradation rate ( Figure 1 ).

[0039] Example 2. Identification of strains

[0040] (1) Morphological identification:

[0041] After culturing the A6 strain obtained in Example 1 in a semi-solid medium for half a month, the colony had neat edges, a smooth surface, and was opaque milky white. The colony diameter was about 0.5-1.0 mm. Using a conventional electron scanning microscope for bacterial physiological and biochemical identification, the isolated strain was stained Gram-positive, the bacteria were rod-shaped, without flagella, and the length of the bacteria was 1-2 μm and the diameter was 0.3-0.5 μm ( Figure 2 ).

[0042] (2) Molecular identification:

[0043] The DNA of the pure culture of the strain obtained in Example 1 was extracted using a soil genomic DNA extraction kit, and then 16S rRNA gene universal primers 27F and 1492E were used for PCR amplification and sequencing to obtain the 16S rRNA gene sequence (SEQ.ID.NO.1). The obtained 16S rRNA gene sequence was input into the Blastn program comparison box of the National Center for Biotechnology Information (NCBI) of the United States, and compared with all nucleotide sequences in the database. A phylogenetic tree was constructed using the 16S rRNA gene sequence ( Figure 3), and found that the 16S rRNA gene fragment of the isolated strain was 1617bp, with a homology of more than 95.0% with species of the genus Dehalobacter, and the highest homology with Dehalobacter sp.TCP1 that degrades trichlorophenol, reaching 97.3%.

[0044] Based on the above physiological and biochemical characteristics and 16S rRNA gene sequence results, the strain isolated in the present invention should be classified as a new variant of the genus Dehalobacter and named Dehalobacter sp. (Dehalobacter sp. DCM).

[0045] The Dehalogenobacter strain DCM was deposited in the General Microbiology Center of the China Culture Collection Administration on November 30, 2021. The deposit address is the Institute of Microbiology, Chinese Academy of Sciences, No. 3, Building 1, Beichen West Road, Chaoyang District, Beijing, and the deposit number is CGMCC No. 24007.

[0046] The 16S rRNA gene sequence of Dehalobacterium strain DCM is as follows:

[0047] ACACATGCGAGTCGAACGGTCCGATACCTAACACCGAGTGCTTACGT

[0048] GTAAACAGCAAGCATCTAAAGCGAGTGCGCGAACGAAGAGAGCGCA

[0049] CCACGCTATTAAAAAGTGACTGACACATAATGCAGAAGAAAACTTTT

[0050] TAGTAGGTGGGAGCGAACGAAGAGAGCGCACCACGCAAATAAAGCT

[0051] TGCTAACACATGCAATGAGCATTGGGTGTTAGGTAGAGGATAGTGGC

[0052] GAACGGGTGAGTAACGCGTGGGTAACCTGCCCTTAAGACCGGGACA

[0053] ACAGCTGGAAACGGCTGCTAATACCGGATGATTTTCCTTGAAGGCAT

[0054] CTTCGAGGAAGTAAAGCTGGCCTCTGAATATGCTAGCGCTTAGGGAT

[0055] GGACCCGCGTCTGATTAGCTAGTTGGTGGGGTAATGGCCTACCAAGG

[0056] CGACGATCAGTAGCCGGCCTGAGAGGGTAAACGGCCACACTGGGAC

[0057] TGAGACACGGCCCAGACTCCTACGGGAGGCAGCAGTGGGGAATCTT

[0058] CCGCAATGGACGAAAGTCTGACGGAGCAACGCCGCGTGTATGAAGA

[0059] AGGCCTTCGGGTTGTAAAATACTGTTGTTAGGGAAGAACTTTAGAGG

[0060] TGTGAATAATGCCTTTAATTGACGGTACCTAACGAGGAAGCCCCGGC

[0061] TAACTACGTGCCAGCAGCCGCGGTAATACGTAGGGGGCAAGCGTTGT

[0062] CCGGAATCATTGGGCGTAAAGGGCGCGTAGGCGGCTATATAAGTCTG

[0063] ATGTGAAAGTGCGGAGCTTAACTCCGTAAAGCATTGGAAACTGTATG

[0064] GCTTGAGGACAGGAGAGGAAAGTGGAATTCCACGTGTAGCGGTGAA

[0065] ATGCGTAGAGATGTGGAGGAACACCAGTGGCGAAGGCGACTTTCTG

[0066] GACTGTAACTGACGCTGAGGCGCGAAAGCGTGGGGAGCGAACAGGA

[0067] TTAGATACCCTGGTAGTCCACGCCGTAAACGATGAGTGCTAGGTGTA

[0068] GAGGGTATCGACCCCTTCTGTGCCGCAGTTAACACAATAAGCACTCC

[0069] GCCTGGGGAGTACGGCCGCAAGGTTGAAACTCAAAGGAATTGACGG

[0070] GGGCCCGCACAAGCGGTGGAGCATGTGGTTTAATTCGACGCAACGCG

[0071] AAGAACCTTACCAAGGCTTGACATCCATAGAATCCTTAAGAGATTAG

[0072] GGAGTGCCCTTCGGGGAACTATGAGACAGGTGGTGCATGGTTGTCGT

[0073] CAGCTCGTGTCGTGAGATGTTGGGTTAAGTCCCGCAACGAGCGCAAC

[0074] CCCTATATTTAGTTGCTAACAGGTAAAGCTGAGAACTCTAGATAGAC

[0075] TGCCGGTGACAAACCGGAGGAAGGTGGGGATGACGTCAAATCATCA

[0076] TGCCCCTTATGTCTTGGGCTACACACGTGCTACAATGGACGGTACAG

[0077] ACGGAAGCGAAGCCGCGAGGTGAAGCAAATCCGAGAAAGCCGTTCT

[0078] CAGTTCGGATTGCAGGCTGCAACTCGCCTGCATGAAGTCGGAATCGC

[0079] TAGTAATCGCAGGTCAGCACACTGCGGTGAATACGTTCCCGGGCCTT

[0080] GTACACACCGCCCGTCACACCACGAAAGTTTGCAACACCCGAAGCCG

[0081] GTGGGGTAACCGTAAGGAGCCAGCCGTCGAA

[0082] Example 3. Degradation performance of Dehalobacterium sp. strain DCM on dichloromethane

[0083] The degradation performance of dichloromethane was studied by investigating the degradation curve, maximum degradation substrate amount and optimal degradation temperature of dichloromethane by Dehalobacterium strain DCM.

[0084] The Dehalobacter sp. DCM culture solution used in the following examples is a bacterial solution obtained by culturing the above-obtained preserved strain (Dehalobacter sp.) in an anaerobic inorganic salt liquid culture medium at 30° C. to the logarithmic growth phase.

[0085] (1) Degradation curve of dichloromethane by Dehalogenobacter strain DCM

[0086] The treatment group was set up as follows: 1 mL of the culture solution of the Dehalobacter strain DCM obtained above was taken and inoculated into an anaerobic bottle containing 100 ml of anaerobic inorganic salt liquid culture medium, and 0.1 mL of a complex vitamin mixture and 10 μL of dichloromethane were added to the culture bottle. Blank control group: except for the absence of Dehalobacter strain DCM, the other culture components were the same. All bottles of the treatment group and the blank control group were placed in a constant temperature box at 30°C for culture. 2 mL of bacterial liquid samples were taken regularly to analyze the substrate and degradation products, among which 1 mL of each group of samples was used to quantitatively analyze the consumption of dichloromethane by the strain using a gas chromatograph according to the method of Implementation Case 1; another 1 mL of each group of samples was centrifuged at 1,2000×g for 10 minutes at room temperature, and the supernatant was transferred to a 2 mL liquid injection bottle, and 1 μL of concentrated sulfuric acid was added to acidify it and then placed in the injection plate of the high performance liquid chromatography to analyze the type and content of dichloromethane degradation products. The instrument parameters were as follows: Agilent 1260LC series high performance liquid chromatograph; the detector was a diode array detector (DAD), the wavelength was set to 210 nm, the elution column was Aminex HPX-87H (300×7.8 mm, 9 μm, Bio-Rad, USA), the flow rate was 0.6 mL / min, and the mobile phase was 100% 4 mM H2SO4; the total running time was 20 min.

[0087] After one week of cultivation and monitoring, it was observed that the content of dichloromethane added to the blank control group was almost not reduced, and no product appeared, which indicated that there was no abiotic degradation reaction of dichloromethane pollutants. In addition, dichloromethane in the treatment group inoculated with Dehalogenobacter strain DCM was rapidly consumed, with a degradation rate of up to 32 μmol D -1 ; Small molecule organic acid products with no side effects on the environment were also detected in the bottle, which were 37.3 μmol acetic acid and 8.9 μmol formic acid ( Figure 4 ).

[0088] (2) Maximum substrate amount of dichloromethane degradation by Dehalobacterium strain DCM

[0089] Use a microsyringe to take different amounts of dichloromethane (10, 20, 30, 40, 50, 100 μL) and add them to anaerobic culture bottles containing 100 mL of anaerobic inorganic salt liquid culture medium. Subsequently, the culture bottles were placed in an ultrasonic cleaner and ultrasonicated at 100W for 20 minutes to promote the dissolution of dichloromethane. Then, 0.1 mL of multivitamins (Table 1) and 1 mL of the above-obtained DCM culture solution of the Dehalogenobacter strain were added to all bottles as inoculation sources; all bottles were placed in a 30°C incubator for culture. 1 mL of bacterial solution samples were taken regularly to monitor the degradation of dichloromethane in a gas chromatograph.

[0090] After 20 days of cultivation and monitoring, it was observed that the Dehalobacter strain DCM in the group with ≥30μL dichloromethane addition was able to completely degrade dichloromethane; while the Dehalobacter strain DCM in the group with 40 and 50μL addition was only able to degrade 30% and 10% of the initial addition, respectively; and the dichloromethane in the group with 100μL addition was not degraded. Therefore, in a 100mL culture system, the Dehalobacter strain DCM can well degrade dichloromethane below 30μL, but dichloromethane exceeding 30μL will inhibit the growth of the Dehalobacter strain DCM.

[0091] (3) The optimal temperature for the degradation of dichloromethane by Dehalogenobacter strain DCM.

[0092] 1 mL of the DCM culture solution of the Dehalogenobacter strain obtained above was inoculated into a culture bottle containing 100 mL of anaerobic inorganic salt liquid culture medium at a ratio of 1% (v / v), and after adding 10 μL of dichloromethane and multivitamins, the culture was cultured in a constant temperature and light-proof incubator at 4°C, 10°C, 16°C, 20°C, 25°C, 30°C, 34°C, 37°C and 40°C, respectively, and the consumption of dichloromethane was regularly monitored by gas chromatography.

[0093] The results showed that after 20 days of cultivation, the Dehalogenobacter strain DCM had no dichloromethane degradation activity below 10°C; dichloromethane degradation was observed in the cultivation temperature range of 16-40°C; the dichloromethane degradation rate was the highest in the cultivation temperature range of 30-37°C ( Figure 5 ).

[0094] Example 4. Degradation of environmental samples containing dichloromethane by Dehalobacterium strain DCM

[0095] A 15L laboratory waste water sample containing about 0.1mM dichloromethane pollutant was collected using a plastic barrel (latitude: 41°54′28″, longitude: 123°35′42″), and sodium sulfide with a final concentration of 0.05mM was added to the water sample to remove oxygen from the water; 1mL of the complex vitamins in Table 1 was added. The culture solution of the Dehalogenobacter strain DCM obtained in Example 3 was centrifuged at a centrifugal force of 1,2000×g for 10 minutes to prepare a cell culture concentrate containing the Dehalogenobacter strain DCM, which was then inoculated into the above-mentioned barrel containing the water sample at a ratio of 0.1% (w / v). After sealing the mouth of the plastic barrel with a rubber stopper, the barrel was placed at 30°C in a dark and static culture condition. During the culture period, the dichloromethane consumption in the system was regularly monitored using a gas chromatograph.

[0096] After half a month of cultivation, it was observed that the dichloromethane in the laboratory waste water sample was completely consumed. It can be seen that the degradation rate of dichloromethane in environmental samples removed by the Dehalogenobacter strain DCM of the present invention can reach 100%, which has a good practical application effect.

Claims

1. A Dehalogenating Bacterium capable of anaerobic degradation of dichloromethane, characterized in that: The strain is Dehalobacter sp. DCM, which was deposited in the General Microbiology Center of China Culture Collection Administration on November 30, 2021. The deposit address is Institute of Microbiology, Chinese Academy of Sciences, No. 3, Building 1, Beichen West Road, Chaoyang District, Beijing, and the deposit number is CGMCC No. 24007.

2. The Dehalogenobacterium having the ability to anaerobically degrade dichloromethane according to claim 1, characterized in that: The bacteria are rod-shaped, Gram-positive, 1-2 μm in length, and 0.3-0.5 μm in diameter.

3. An application of the Dehalogenobacter according to claim 1, characterized in that: The strain is used to degrade dichloromethane pollutants in the environment.

4. An application of the Dehalogenobacter according to claim 1, characterized in that: The strain is used to degrade dichloromethane pollutants in the environment under anaerobic conditions.

5. The use of Dehalobacterium according to claim 3, characterized in that: The environment is water, sediment or soil.

6. A preparation for degrading dichloromethane pollutants, characterized in that: The preparation contains the Dehalogenobacter strain DCM as claimed in claim 1.

7. The preparation for degrading dichloromethane pollutants according to claim 6, characterized in that: The preparation contains the cell culture, cell culture concentrate, cell culture filtrate or culture suspension of the strain.

8. A method for degrading dichloromethane pollutants, characterized in that: The strain described in claim 1 or the bacterial agent described in claim 6 is inoculated into the environmental sample to be treated, and sodium sulfide with a final concentration of 0.05 mM is added to the environmental sample as a deoxidizer, thereby achieving anaerobic degradation of dichloromethane in the environmental sample.

9. The method according to claim 8, characterized in that: The inoculation amount of the strain or bacterial agent is 0.1% (w / v).

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