CN112458001B

CN112458001B - Bacterial strain capable of degrading polycyclic aromatic hydrocarbon and application thereof

Info

Publication number: CN112458001B
Application number: CN202010886837.6A
Authority: CN
Inventors: 唐鸿志; 刘耘莉; 胡海洋; 许平; 陶飞
Original assignee: Shanghai Jiaotong University
Current assignee: Shanghai Jiaotong University
Priority date: 2020-07-30
Filing date: 2020-08-28
Publication date: 2022-09-27
Anticipated expiration: 2040-08-28
Also published as: CN112458001A

Abstract

The invention provides a bacterial strain capable of degrading polycyclic aromatic hydrocarbon and application thereof. The invention provides a bacterial strain capable of degrading polycyclic aromatic hydrocarbon, wherein the preservation number of the bacterial strain is CCTCC NO: M2020186, the preservation date is 2020, 06 and 08 days, the preservation unit is China center for type culture Collection, and the preservation address is university of Wuhan, China. The strain provided by the invention can grow in a culture environment with polycyclic aromatic hydrocarbons such as naphthalene, fluorene, DBF, DBT and the like as the only carbon source, and has a degradation effect on the polycyclic aromatic hydrocarbons such as naphthalene, fluorene, DBF, DBT and the like, wherein the strain has high-efficiency degradation rate and degradation speed on naphthalene, so that the strain can realize a biological environment restoration treatment effect with high efficiency, cleanness and no secondary pollution, and has the characteristics of low cost, simple and convenient operation, mild reaction conditions and energy conservation; in addition, the strain provided by the invention can tolerate various antibiotics, and provides an operation example for pollution remediation in the actual environment.

Description

Bacterial strain capable of degrading polycyclic aromatic hydrocarbon and application thereof

Technical Field

The invention relates to the technical field of microorganisms, and particularly relates to a strain capable of degrading polycyclic aromatic hydrocarbons and application thereof.

Background

Polycyclic Aromatic Hydrocarbons (PAHs) refer to hydrocarbons consisting of two or more benzene rings, and are a class of organic pollutants widely present in the environment. PAHs are generally characterized by high melting points and high boiling points; insoluble in water, and easily soluble in organic solvents such as benzene, diethyl ether, chloroform, etc.; and as the number of benzene rings is increased, the water solubility is reduced, and the bioavailability and degradability are reduced.

PAHs are mainly derived from products of incomplete combustion or low-temperature treatment (100-300 ℃) of organic compounds under high-temperature conditions (500-800 ℃), and the organic compounds are mainly derived from substances containing hydrocarbon, such as petroleum, coal, wood, gas fuel, paper and the like. With the rapid development of economy, the current situation of PAHs pollution in China is very severe. According to preliminary estimation, the annual emission of PAHs in China exceeds 25000 tons, and the average emission density of cities is 158kg/km ² The local discharge density in rural areas is up to 479kg/km ² . PAHs can cause great pollution to the environment such as soil, atmosphere, water body and the like, seriously threaten the health and ecological safety of human bodies, and have the characteristics of cytotoxicity, immunotoxicity, carcinogenesis, teratogenesis and mutagenesis. The toxicity of PAHs has attracted public attention from countries around the world. As early as 1979, 16 PAHs have been listed as the priority pollutants for monitoring by the united states national Environmental Protection Agency (EPA). Therefore, PAHs in various media in the environment are efficiently degraded, pollution of the PAHs is eliminated, and the method has important significance for maintaining human health and protecting the environment.

The existing methods for treating polycyclic aromatic hydrocarbon pollution mainly comprise physical methods, chemical methods and biological methods. The physical method mainly includes an adsorption method, but the adsorption method has a high requirement on an adsorption material and causes a problem of cost increase, and the regeneration and utilization of the adsorption material are problems to be solved urgently. The chemical method mainly comprises an oxidation method, but the method has the disadvantages of high energy consumption, narrow application range and easy generation of secondary pollution. The removal of polycyclic aromatic hydrocarbons such as naphthalene, fluorene and the like and their heterocyclic derivatives DBF, DBT from polluted environments by conventional physical and chemical methods is an expensive and environmentally unfriendly process. Compared with a physical and chemical method, the microbial degradation has the advantages of low cost, high efficiency, small harmfulness and effective selection for repairing polluted soil and water, and the microbial metabolism can effectively degrade toxic substances into harmless intermediates and end products, so that the microbial degradation can be further used for repairing the environment polluted by various polycyclic aromatic hydrocarbon compounds.

Naphthalene (naphthalene) is the most common bicyclic aromatic compound, is the main component of coal tar and creosote, and is one of polycyclic aromatic hydrocarbons with the strongest water solubility and volatility. The long-term naphthalene contact can cause the change of blood components in the human body, the activity of liver transaminase is increased, jaundice appears, and the health of the human body is seriously threatened; naphthalene also has a toxic effect on aquatic organisms, manifested by suppression of respiratory intensity, reduction of chlorophyll content, and finally, the atrophy and death of aquatic organisms. Fluorene is a polycyclic aromatic hydrocarbon typically containing 3 rings, has a characteristic aromatic odor similar to naphthalene, is present in high-boiling components of automobile exhaust gas and coal tar, and is listed in a list of 3 carcinogens by the international cancer research organization of the world health organization due to the toxic action of carcinogenesis and the like on organisms. DBF and DBT are typical heterocyclic aromatic compounds of fluorene. DBF is also called dibenzo-furan, dibenzopyran, epoxy biphenyl and the like, is an important fine chemical raw material, is a parent compound of dioxin substances, and has lower toxicity compared with chlorinated DBF, so that the research on the biodegradation of DBF has important significance on the repair of dibenzo-dioxin and polychlorinated DBF. DBT is also called dibenzothiophene and can be used as a drug intermediate. DBT is a suspected mutagen and large inhalations can cause muscle atrophy and ocular stinging, causing kidney and bladder cancer, damage to the central nervous system and liver.

At present, a plurality of strains capable of degrading naphthalene, fluorene, DBF and DBT respectively have been found, however, strains capable of degrading naphthalene, fluorene, DBF and DBT simultaneously are very rare in previous research reports, and therefore, a person skilled in the art is dedicated to develop a strain capable of degrading polycyclic aromatic hydrocarbons, which can degrade a plurality of polycyclic aromatic hydrocarbons such as naphthalene, fluorene, DBF and DBT simultaneously, so as to achieve a clean, efficient and secondary pollution-free environmental remediation effect.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the technical problem to be solved by the present invention is to provide a strain capable of degrading polycyclic aromatic hydrocarbons.

In order to realize the aim, the invention provides a bacterial strain capable of degrading polycyclic aromatic hydrocarbon, wherein the preservation number of the bacterial strain is CCTCC NO: M2020186, the preservation date is 2020, 06, 08 days, the preservation unit is China center for type culture Collection, and the preservation address is university of Wuhan, China.

Further, the strain is pseudomonas.

The second aspect of the present invention provides a screening method for the above strains, comprising the following steps:

collecting a soil sample in a polycyclic aromatic hydrocarbon polluted area, adding the soil sample into a culture medium containing polycyclic aromatic hydrocarbon for culture, and obtaining a single colony which can grow by taking the polycyclic aromatic hydrocarbon as a unique carbon source.

The third aspect of the invention provides an application of the strain in degrading polycyclic aromatic hydrocarbons.

Further, the polycyclic aromatic hydrocarbon includes one or more of naphthalene, fluorene, DBF, and DBT.

The fourth aspect of the present invention provides a method for degrading a pollutant containing polycyclic aromatic hydrocarbon, comprising the following steps: and culturing the strain, and adding the cultured strain into the pollutant containing the polycyclic aromatic hydrocarbon.

Further, the strain was cultured at 25 ℃.

Further, the strain was shake-cultured at 200 rpm.

Further, in the culture process of the strain, the addition amount of naphthalene was 50mg, and the addition amounts of fluorene, DBF and DBT were 5mg, respectively.

Further, the degradation rate of the strain on naphthalene, fluorene, DBF and DBT is 11.905mgL respectively ^-1 h ^-1 、0.631mgL ^-1 h ^-1 、0.676mgL ^-1 h ^-1 、0.386mgL ^-1 h ^-1 。

The strain provided by the invention can grow in a culture environment with polycyclic aromatic hydrocarbons such as naphthalene, fluorene, DBF, DBT and the like as the only carbon source, and has a degradation effect on the polycyclic aromatic hydrocarbons such as naphthalene, fluorene, DBF, DBT and the like, wherein the strain has high-efficiency degradation rate and degradation speed on naphthalene, so that the strain can realize a biological environment restoration treatment effect with high efficiency, cleanness and no secondary pollution, and has the characteristics of low cost, simple and convenient operation, mild reaction conditions and energy conservation; in addition, the strain provided by the invention can tolerate various antibiotics, and provides an operation example for pollution remediation in the actual environment.

The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, the features and the effects of the present invention.

Drawings

FIG. 1 is a phylogenetic tree constructed after the 16SrRNA sequence of the strain capable of degrading polycyclic aromatic hydrocarbons provided by the invention is analyzed and compared;

FIGS. 2A-2D are OD of strains grown in MSM medium containing naphthalene, fluorene, DBF and DBT under different temperature conditions ₆₀₀ A line graph of (a);

FIGS. 3E-3H are OD of strain grown in MSM medium containing naphthalene, fluorene, DBF and DBT at different rotation speeds ₆₀₀ A line graph of (a);

FIGS. 4I-4L are OD values of strains grown in MSM medium having different contents of naphthalene, fluorene, DBF and DBT at 25 ℃ and 200rpm ₆₀₀ A line graph of (a);

FIGS. 5M-5P are a line graph showing the degradation amounts of naphthalene, fluorene, DBF and DBT by the strain and the OD of the strain growth ₆₀₀ A line graph of (a);

FIGS. 6A-6B are schematic diagrams showing analysis of intermediate metabolites during naphthalene degradation by the strain;

FIGS. 7C-7E are schematic diagrams showing analysis of intermediate metabolites during degradation of fluorene by the strain;

FIGS. 8F-8H are schematic diagrams of intermediate metabolite analysis during DBF degradation by this strain;

FIGS. 9I-9K are schematic diagrams of intermediate metabolite analysis during DBT degradation by this strain;

FIG. 10 shows the predicted naphthalene degradation gene cluster in the genome of this strain.

Detailed Description

The technical contents of the preferred embodiments of the present invention will be more clearly and easily understood by referring to the drawings attached to the specification. The present invention may be embodied in many different forms of embodiments and the scope of the invention is not limited to the embodiments set forth herein.

The invention mainly provides a bacterial strain capable of degrading polycyclic aromatic hydrocarbon, which is elaborated in detail from the following aspects:

example 1 screening, isolation and identification of strains

1. Sampling a sample

Collecting soil or mud samples of petrochemical engineering polluted sites polluted by certain polycyclic aromatic hydrocarbon of Tianjin.

2. Screening and isolation of strains

Weighing 5g of sample, adding the sample into a 50mLMSM liquid culture medium, adding 20mg of naphthalene, and culturing for 5 days at the temperature of 30 ℃ and the speed of 200 rpm;

transferring the culture solution cultured for 5 days into 50mL of fresh MSM culture medium according to the inoculation amount of 5%, adding 20mg of naphthalene, continuously culturing for 5 days, repeating for three times, diluting the culture solution of the last time, coating the diluted culture solution on an inorganic salt solid culture medium, covering an inverted flat plate with 50mg of naphthalene, and culturing at 30 ℃ until a single colony grows out;

and (3) selecting a single bacterium, dropping the single bacterium into a fresh inorganic salt liquid culture medium, selecting a strain with the fastest growth, carrying out streaking separation, and repeating for multiple times until a purified single bacterium is obtained.

Wherein the MSM liquid culture medium (1L) comprises 6.8g K ₂ HPO ₄ ·3H ₂ O，3.7g KH ₂ PO ₄ ，0.1g MgSO ₄ ，1.0g Na ₂ SO ₄ And 0.5mL of metal ion buffer;

wherein the metal ion buffer solution (1L) comprises 0.3g FeCl ₂ ·4H ₂ O，0.02g MnCl ₂ ·4H ₂ O，0.0124g H ₃ BO ₃ ，0.0034g CuCl ₂ ·2H ₂ O，0.038g CoCl ₂ ·6H ₂ O，0.014g ZnCl ₂ And 0.04g of Na ₂ MoO ₄ ·2H ₂ Dissolving O in 0.1mol/L hydrochloric acid solution;

the inorganic salt solid culture medium is prepared by adding 1.5% agar powder into the MSM liquid culture medium.

3. Identification of strains

The strain is identified as gram-negative bacteria, prefers oxygen, is amplified and sequenced by using 16SrRNA universal primers (27F5 '-AGAGTTTGATCCTGGCTCA-3' and 1492R5 '-AGAGTTTGATCCTGGCTCA-3'), and the amplification result is sent to a company for sequencing.

The 16S rRNA sequences of the strains were retrieved in BLAST using nucleotide BLAST (BLASTn) in NCBI database (https:// BLAST. NCBI. nlm. nih. gov/BLAST. cgi), the Pseudomonas standard strains were retrieved using RDP database (http:// RDP. cme. msu. edu /), and phylogenetic trees were established using the adjacency (NJ) method of MEGA 7.

As shown in FIG. 1, the strain has the closest relationship with Pseudomonas.

The strain is identified as pseudomonas MPDS (Pseudomonas brassicearum MPDS) by combining the above physiological and biochemical bacteriological characteristics and phylogenetic tree analysis, and is preserved to China center for type culture Collection (CCTCC NO: M2020186) in 2020, 06 and 08 days.

Example 2 optimal growth conditions for this Pseudomonas MPDS

1. Optimal growth temperature of the strain: the strains were inoculated into 50mL MSM medium containing 50mg naphthalene, 2.5mg fluorene, 2.5mg DBF and 2.5mg DBT, respectively, subjected to shake cultivation at 25 deg.C, 30 deg.C, 37 deg.C, 42 deg.C, 200rpm, respectively, and their OD was measured with a spectrophotometer at regular intervals ₆₀₀ The measurement results are shown in FIGS. 2A-2D.

Wherein FIG. 2A is OD of strain grown in MSM medium containing 50mg naphthalene under different temperature conditions ₆₀₀ FIG. 2B is a graph showing OD of strains grown in MSM medium containing 2.5mg of fluorene under different temperature conditions ₆₀₀ Fig. 2C is a graph showing, under different temperature conditions,OD of strain grown in MSM medium containing 2.5mg DBF ₆₀₀ FIG. 2D is a graph showing the OD of the strain grown in MSM medium containing 2.5mg DBT under different temperature conditions ₆₀₀ A line graph of (a);

as can be seen from FIGS. 2A-2D, the optimal growth temperature for the strain was 25 ℃.

2. Optimal growth speed of the strain: the strains were inoculated into 50mL of MSM medium containing 50mg of naphthalene, 2.5mg of fluorene, 2.5mg of DBF and 2.5mg of DBT, respectively, and were subjected to shake cultivation at 50rpm, 100rpm, 200rpm and 25 ℃ respectively, and OD was measured at regular intervals by a spectrophotometer ₆₀₀ The results are shown in FIGS. 3E-3H.

Wherein, FIG. 3E is OD of strain grown in MSM medium containing 50mg naphthalene at different rotation speeds ₆₀₀ FIG. 3F is the OD of the strain grown in MSM medium containing 2.5mg of fluorene at different rotation speeds ₆₀₀ FIG. 3G is the OD of the strain grown in MSM medium containing 2.5mg DBF at different rotation speeds ₆₀₀ FIG. 3H is a graph showing the OD of the strain grown in MSM medium containing 2.5mg DBT at different rotation speeds ₆₀₀ A line graph of (a);

as can be seen from FIGS. 3E-3H, the optimum growth rate of the strain was 200 rpm.

3. Optimal substrate addition amount of the strain: inoculating the strains into 50mL MSM culture medium, adding

naphthalene

10, 50, 100mg, adding fluorene, DBF and DBT 2.5, 5, 10, 20, 50mg, culturing at 25 deg.C and 200rpm, measuring OD at regular intervals with spectrophotometer ₆₀₀ The test results are shown in FIGS. 4I-L.

Wherein FIG. 4I is the OD of the strain grown in MSM medium with different naphthalene content at 25 deg.C and 200rpm ₆₀₀ FIG. 4J is the OD of the strain grown in MSM medium with different fluorene contents at 25 ℃ and 200rpm ₆₀₀ FIG. 4K is the OD of the strain grown in MSM medium with different DBF content at 25 ℃ and 200rpm ₆₀₀ FIG. 4L is the OD of the strain grown in MSM medium with different DBT content at 25 ℃ and 200rpm ₆₀₀ A line graph of (a);

as can be seen from FIGS. 4I-4K, the optimum amount of naphthalene was 50mg, and the optimum amounts of fluorene, DBF and DBT were all 5 mg.

Example 3 ability of this Pseudomonas MPDS to degrade naphthalene, fluorene, DBF and DBT

Respectively inoculating the strains into 50mL of MSM culture medium, wherein the addition amount of naphthalene is 50mg, and the addition amounts of fluorene, DBF and DBT are 5mg, culturing at 25 ℃ and 200rpm, collecting culture solutions at different culture periods, respectively extracting the culture solutions with equal volume of ethyl acetate, respectively carrying out High Performance Liquid Chromatography (HPLC) detection on extract liquor, and respectively detecting the content of naphthalene, fluorene, DBF and DBT in the culture solutions.

Wherein, the detection conditions of the high performance liquid chromatography are Agilent technologies1200 instrument equipped with eclipse XDB-C18(5 μm, 4.6X 150mm) analytical column, mobile phase A: ultra I water, mobile phase B: chromatographic grade methanol, in a ratio of 20: 80; the flow rate is 0.5 mL/min, and the column temperature is 30 ℃; the detection wavelengths were 275nm (naphthalene), 280nm (DBF), 254nm (fluorene and DBT). Preparing naphthalene, fluorene, DBF and DBT standard substances with different concentration gradients, measuring peak areas under corresponding concentrations, and drawing a standard curve. And converting the peak area measured in the sample from the standard curve to obtain the substrate content.

FIG. 5M is a line graph showing the degradation of naphthalene by MPDS of the Pseudomonas bacteria and the OD of the strain growth ₆₀₀ Line graphs, FIG. 5N is a line graph of the degradation amount of fluorene by the Pseudomonas MPDS and the OD of the strain growth ₆₀₀ The line graph, FIG. 5O is the line graph of the DBF degradation amount of the Pseudomonas MPDS and the OD of the strain growth ₆₀₀ Line graphs, FIG. 5P is a line graph showing the amount of DBT degradation by MPDS of the Pseudomonas bacteria and the OD of strain growth ₆₀₀ A line drawing; wherein, a-solidup represents the substrate content of the blank control group, ■ represents the OD of the blank control group ₆₀₀ (ii) a t.X represents the substrate content of the experimental group, ● represents the OD of the experimental group ₆₀₀ ；

As can be seen from FIGS. 5M-5P, the degradation rates of the strain on naphthalene, fluorene, DBF and DBT are 11.905mgL respectively ^-1 h ^-1 、0.631mgL ^-1 h ^-1 、0.676mgL ^-1 h ^-1 、0.386mgL ^-1 h ^-1 。

Example 4 intermediate metabolite analysis of the Pseudomonas MPDS for the degradation of naphthalene, fluorene, DBF and DBT

1. Sample preparation: activating the strain, transferring the strain solution to a fresh LB culture medium for overnight culture, centrifugally collecting thalli at 4 ℃, re-suspending with PBS buffer solution, centrifugally collecting thalli, repeatedly washing for 2 times, starving the thalli for 3 hours, and then diluting OD of resting cells with the PBS buffer solution ₆₀₀ When the amount of each of naphthalene and fluorene was 5.0 mg, 50mg, 2.5mg, DBF and DBT were added to the reaction solution to perform resting cell reaction. Sampling at different times, adding equal volume of ethyl acetate for extraction, shaking and extracting by using a separating funnel, concentrating by using a rotary evaporator, and taking 100 mu L of organic phase for LC-MS detection. Silanization derivatization was performed in 15. mu.L, followed by GC-MS detection.

2. LC-MS detection: the LC-MS detection conditions were liquid chromatography (Agilent HPLC1290-MS6230), column temperature 30 ℃, water: methanol 20%: 80% and flow rate 0.4mL ^-1 Injection volume 5. mu.L, detection wavelength 275nm, 280nm, 254 nm.

3. And (3) GC-MS detection: the detection condition is gas chromatography (Agilent6850/5975C), the detector temperature is 250 ℃, the helium flow is 1 mL/min, and the temperature rise process is as follows: the initial temperature was 50 ℃ and held for 2 minutes; the temperature was raised from 50 ℃ to 250 ℃ at a rate of 15 ℃/min and held for 10 minutes.

4. And (3) detection results: by LC-MS, naphthalene products 1, 2-dihydroxynaphthalene, salicylic acid and catechol were detected (FIG. 6A), demonstrating that its metabolic pathway is a salicylic acid degradation pathway (FIG. 6B);

the products of DBF, 3- (3 '-oxybenzofuran-2' -yl) propionic acid, 2- (3 '-oxybenzofuran-2' -yl) acetic acid, 2- (3 '-hydroxy-2', 3 '-dihydrobenzofuran-2' -yl) acetic acid, 2-oxo-2- (2-hydroxyphenyl) acetic acid, salicylic acid and catechol were detected by LC-MS (fig. 7C), silanized salicylic acid was detected by GC-MS (fig. 7D), demonstrating ring-opening degradation of salicylic acid by the 3,4 plus hydroxyl side bis-addition pathway (fig. 7E);

DBT products including 1, 2-dihydroxydibenzothiophene, 3-hydroxy-2-formylbenzothiophene, 2, 3-dihydroxybenzothiophene and thiosalicylic acid (FIG. 8F), detection of silanized thiosalicylic acid by GC-MS (FIG. 8G), demonstrating that DBT is also degraded by ring opening via the lateral dioxygen pathway to 3,4 plus hydroxyl groups (FIG. 8H);

fluorene products were detected to include in 9-fluorenol, 2-propanoic acid-1-indanone and 2-aceto-1-indanone by LC-MS (fig. 9I), and 9-fluorenone was detected by GC-MS (fig. 9J), which involved metabolites of both pathways, so that the metabolic pathway for degradation of fluorene by MPDS still needed further investigation (fig. 9K).

Example 5 detection of resistance of the Pseudomonas MPDS to multiple antibiotics

Dipping activated strains by sterilized cotton, uniformly coating the strains on an M-H solid culture medium, after liquid is dried in the air, attaching drug sensitive test paper containing different antibiotics to the center of a plate, inversely placing the plate in a 30-DEG incubator for overnight culture, measuring and recording the diameter of an inhibition zone after the inhibition zone is grown, comparing the diameter with an antibiotic standard table as shown in table 1, wherein R represents resistance, I represents medium, and S represents sensitivity, and the strains MPDS have resistance to amoxicillin, nitrofurantoin, erythromycin, lincomycin, clindamycin, ampicillin, penicillin, chloramphenicol, norfloxacin, vancomycin and cefazolin.

The formula (1L) of the M-H medium is as follows: 2.0g of beef powder, 1.5g of soluble starch and 17.5g of acid hydrolyzed casein, adjusting the pH to 7.4, and adding 1.5% agar powder to prepare a solid culture medium.

TABLE 1 detection of the antibiotic resistance of the strain Pseudomonas brassicerarum MPDS

Example 6 genomic analysis of the Pseudomonas MPDS and mining of the associated degradative genes

Culturing the thalli to a logarithmic phase, centrifugally collecting the thalli at 4 ℃, resuspending the thalli by using PBS buffer solution, centrifugally collecting the thalli, repeatedly washing for 2 times, quickly freezing the thalli by using liquid nitrogen, and then storing the thalli in a refrigerator at-80 ℃. The dry ice is transported to Shanghai Paisenno company to carry out the machine sequencing by utilizing an Illumina NovaSeq sequencing platform and a Pacbiosequel sequencing platform, and the whole genome sequencing of Pseudomonas brassicerarum MPDS is completed.

As shown in fig. 10, the entire naphthalene degradation gene cluster nahaaaabacadbfced was found in the genome of strain MPDS, highly similar (> 98%) to the sequence of the naphthalene degradation gene cluster of Pseudomonas stutzeri, and degradation genes of downstream salicylic acid and catechol as well as degradation genes of other monocyclic compounds were found. Meanwhile, the existence of genes similar to the reported fluorene, DBF and DBT degradation genes is not found, and the MPDS genome may contain new degradation genes to be excavated.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims

1. The strain capable of degrading the polycyclic aromatic hydrocarbon is characterized in that the strain is Pseudomonas (Pseudomonas brassicerarum) MPDS, the preservation number is CCTCC NO: M2020186, the preservation date is 2020, 06 and 08 days, the preservation unit is China center for type culture Collection, and the preservation address is university of Wuhan, China.

2. The strain of claim 1, wherein the polycyclic aromatic hydrocarbon is one or more of naphthalene, fluorene, DBF and DBT.

3. A method for degrading pollutants containing polycyclic aromatic hydrocarbons is characterized by comprising the following steps:

culturing the strain of claim 1, and adding the cultured strain to the pollutant containing polycyclic aromatic hydrocarbon, wherein the polycyclic aromatic hydrocarbon is one or more of naphthalene, fluorene, DBF and DBT.

4. The method of claim 3, wherein the strain is cultured at 25 ℃.

5. The method of claim 3, wherein the strain is shake-cultured at 200 rpm.

6. The method according to claim 3, wherein the naphthalene content is 50mg and the fluorene, DBF and DBT contents are 5mg, respectively.