Pseudomonas aeruginosa and fungicide thereof, crude oil removal method and crude oil associated gas oil removal method

Abstract

The invention relates to the technical field of biology, in particular to Pseudomonas aeruginosa, a bacterial agent of the Pseudomonas aeruginosa, a method for removing crude oil and a method for removing oil from crude oil associated gas. The preservation number of the pseudomonas aeruginosa is CGMCC (China General Microbiological Culture Collection Center) No.9039. The pseudomonas aeruginosa can effectively remove crude oil in an oil-containing environment, has the advantages of low cost, simplicity in operation, good effect, environmental friendliness and the like when being used for removing oil, and is a green and sustainable environment treatment technology.

Description

Technical Field

[0001] This invention relates to the field of biotechnology, specifically to a Pseudomonas aeruginosa bacterium and its inoculant, a method for removing crude oil, and a method for removing oil from associated gas of crude oil. Background Technology

[0002] In oilfield production, waste materials or mixtures containing crude oil, such as oil sludge, oil sands, and oily wastewater, are often generated. Direct discharge or improper treatment of these materials not only wastes resources but also causes serious environmental pollution. Therefore, effectively separating and removing crude oil from these materials is crucial for improving resource utilization and reducing environmental pollution. Commonly used traditional technologies include gravity sedimentation and filtration, often involving the addition of chemical agents to alter the physicochemical properties of the materials, making crude oil easier to separate. For example, flocculants are used to aggregate crude oil into clumps for easier separation.

[0003] Meanwhile, the recovery and utilization of associated gas during crude oil extraction is a crucial aspect of the petroleum development industry. Associated gas refers to the gases produced alongside crude oil during extraction and production, primarily including natural gas, CO2, nitrogen, and small amounts of oil and liquid droplets. Removing oil from associated gas is essential for improving gas quality and ensuring subsequent processing and utilization. Commonly used traditional technologies include condensation separation, which lowers the gas temperature, causing oil and liquid droplets to condense and separate. Another method is adsorption separation, which utilizes the adsorption properties of adsorbents to adsorb oil and liquid droplets from the gas. This method is effective for separating tiny oil droplets, but the regeneration and replacement costs of the adsorbent are high. Summary of the Invention

[0004] To overcome the environmental pollution caused by crude oil-containing waste or mixtures in existing oilfield production processes, such as the oily wastewater still containing a small amount of crude oil after separation by a three-phase separator; and the high energy consumption and cost of removing crude oil-containing gases generated along with crude oil during crude oil extraction and production, this invention provides a strain of Pseudomonas aeruginosa and its inoculant, a method for removing crude oil, and a method for removing associated gas from crude oil. The application of Pseudomonas aeruginosa for oil removal described in this invention has advantages such as low cost, simple operation, and minimal secondary pollution, making it a green and sustainable environmental governance technology.

[0005] To achieve the above objectives, the first aspect of the present invention provides a strain of Pseudomonas aeruginosa, G028, with the accession number CGMCC No. 9039.

[0006] A second aspect of the present invention provides a bacterial agent containing the Pseudomonas aeruginosa strain G028 described in the present invention.

[0007] A third aspect of the present invention provides the application of the *Pseudomonas aeruginosa* strain G028 described in the present invention and / or the bacterial agent described in the present invention in oil removal.

[0008] A fourth aspect of the present invention provides a method for removing crude oil, the method comprising: contacting the Pseudomonas aeruginosa strain G028 of the present invention and / or the bacterial agent of the present invention with a material containing crude oil.

[0009] The fifth aspect of this invention provides a method for removing oil from associated gas in crude oil, the method comprising:

[0010] (1) Contact the associated gas from crude oil with alkaline solution;

[0011] (2) Mix the liquid product from step (1) with the Pseudomonas aeruginosa strain G028 or the bacterial agent described in this invention.

[0012] The *Pseudomonas aeruginosa* strain G028 described in this invention is a hydrocarbon-degrading bacterium. Applying this strain for oil removal can effectively remove crude oil, offering advantages such as simple operation, low cost, good results, and environmental friendliness. Furthermore, the *Pseudomonas aeruginosa* strain G028 described in this invention can achieve stable oil removal in environments containing sulfides (e.g., sulfur content of 50-200 mg / L). Moreover, the *Pseudomonas aeruginosa* strain G028 described in this invention does not exhibit antagonistic effects with desulfurization strains (e.g., *Bacillus jsHD-2* for thermal denitrification and *Bacillus jsHD-4* for composting), and they can co-grow. The oil removal product can be directly subjected to biological desulfurization.

[0013] Biological Preservation

[0014] The Pseudomonas aeruginosa strain G028 of this invention was deposited on April 11, 2014, at the China General Microbiological Culture Collection Center (address: No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, 100101, China) (abbreviation of depositary institution: CGMCC), with accession number CGMCC No. 9039.

[0015] The *Geobacillus thermodenitrificans* strain JSHD-2 provided by this invention was deposited on March 5, 2013, at the China General Microbiological Culture Collection Center (address: No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, 100101, China) (abbreviation of depositary institution: CGMCC), with accession number CGMCCNo.7271.

[0016] The Geobacillus toebii strain JSHD-4 provided by this invention was deposited on March 5, 2013, at the China General Microbiological Culture Collection Center (address: No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, 100101, China) (abbreviation of depositary institution: CGMCC), with accession number CGMCC No. 7273. Attached Figure Description

[0017] Figure 1 The image shows the growth of G028 in an oily environment and its oil removal effect. Detailed Implementation

[0018] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0019] The first aspect of this invention provides a strain of Pseudomonas aeruginosa, G028, which is deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 9039.

[0020] The strains described in this invention were isolated and screened from the produced fluid of oil wells in Jiangsu Oilfield.

[0021] The screening method is not particularly limited and can be any conventional method used in the field for screening new strains. For example, the screening method may be as follows: collect oilfield produced fluid, inoculate it into a culture medium at a volume ratio of 5%, and culture it in a closed shaking incubator at 37°C for 3-5 days. Stop the culture when the culture medium becomes turbid or flocculent. Dilute the enriched solution with sterile water, spread the diluted solution onto solid culture plates, and incubate them in a 37°C incubator for 24-48 hours until single colonies appear. Select a single colony and place it into an EP tube containing 1 mL of liquid culture medium, incubate it in a shaking incubator for 24 hours, and streak it onto the plate again. Repeat the single colony selection 3-5 times.

[0022] In this invention, the culture medium can be a conventional culture medium capable of culturing Pseudomonas aeruginosa. According to a preferred embodiment of this invention, the culture medium contains: 0.2g MgSO4, 0.02g CaCl2, 0.8g KH2PO4, 1.2g K2HPO4, 1.2g NH4NO3, 0.05g FeCl3, 500mL H2O, pH 7.2-7.5, with 0.5% crude oil as the sole carbon source.

[0023] Genomic DNA of the bacterial strain was extracted using a bacterial genomic DNA extraction kit and in accordance with the instructions. After PCR amplification and DNA quality assessment using universal 16S rDNA primers 805R and 8F, the DNA was sent to Nanjing Genscript Biotech Co., Ltd. for 16S rRNA gene sequencing. The 16S rRNA sequence is shown in SEQ ID NO:1.

[0024] The species of this strain was identified by 16S rDNA sequencing, and it was determined to be Pseudomonas aeruginosa, named G028.

[0025] Pseudomonas aeruginosa strain G028 was deposited at the China General Microbiological Culture Collection Center (address: No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, 100101, China), accession number CGMCC No. 9039; deposit date: April 11, 2014.

[0026] A second aspect of the present invention provides a bacterial agent containing the Pseudomonas aeruginosa strain G028 described in the present invention.

[0027] In this invention, the preparation method of the bacterial agent can be a conventional preparation method in the art; this is an example, but does not limit the scope of the invention. According to a preferred embodiment of the invention, the above-mentioned Pseudomonas aeruginosa is inoculated into a liquid culture medium for cultivation.

[0028] According to the present invention, the liquid culture medium can be a conventional culture medium capable of culturing Pseudomonas aeruginosa. In a preferred embodiment, the liquid culture medium contains 0.2 g of MgSO4, 0.02 g of CaCl2, 0.8 g of KH2PO4, 1.2 g of K2HPO4, 1.2 g of NH4NO3, 0.05 g of FeCl3, 500 mL of H2O, and has a pH of 7.2-7.5, with crude oil as the carbon source.

[0029] In this invention, the crude oil source is crude oil from oil wells in Jiangsu Oilfield.

[0030] According to the present invention, the culture conditions may include: a temperature of 30-37°C and a time of 16-24 hours.

[0031] According to a preferred embodiment of the present invention, the viable bacteria count in the bacterial agent is 10. 8 cfu / mL or higher.

[0032] A third aspect of the present invention provides the application of the *Pseudomonas aeruginosa* strain G028 described in the present invention and / or the bacterial agent described in the present invention in oil removal.

[0033] A fourth aspect of the present invention provides a method for removing crude oil, the method comprising: contacting the Pseudomonas aeruginosa strain G028 of the present invention and / or the bacterial agent of the present invention with a material containing crude oil.

[0034] In this invention, the amount of microbial agent inoculated into the crude oil-containing material can be selected within a wide range. According to a preferred embodiment of the invention, the microbial agent is 0.1%-5% of the total volume of the crude oil-containing material, for example, 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, or 4.5%. For example, according to one embodiment of the invention, the amount of microbial agent inoculated into the crude oil-containing material is 0.1%-5% of the total volume of the crude oil-containing material.

[0035] In this invention, the microbial agent also contains desulfurizing strains. The range of desulfurizing strains that can be selected is relatively wide. This is an illustrative example, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the desulfurizing strain is Geobacillus thermodenitrificans strain JSHD-2 and / or Geobacillus toebii strain JSHD-4.

[0036] In this invention, the concentration of the desulfurizing strain in the microbial agent can be selected from a wide range, which is illustrative but does not limit the scope of the invention. According to a preferred embodiment of the invention, the concentration of the desulfurizing strain in the microbial agent is 10. 7 -10 8 cfu / mL.

[0037] In this invention, the concentration range of *Pseudomonas aeruginosa* strain G028 in crude oil-containing materials is relatively wide, which is illustrative but does not limit the scope of the invention. According to a preferred embodiment of the invention, the concentration of *Pseudomonas aeruginosa* strain G028 in crude oil-containing materials is 10... 7 -10 8 cfu / mL.

[0038] In this invention, the crude oil content in the crude oil-containing material can be selected from a wide range. This is an illustrative example, but does not limit the scope of this invention. The crude oil content is 5-20 mg / L, for example, 5 mg / L, 8 mg / L, 10 mg / L, 12 mg / L, 15 mg / L, and 18 mg / L.

[0039] In this invention, the crude oil-containing material also contains sulfides. The range of types of sulfides that can be selected is relatively wide. This is an illustrative example, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the sulfides are selected from sulfides of Group IA metal elements and / or hydrosulfides of Group IA metal elements, such as sodium sulfide and sodium hydrosulfide.

[0040] In this invention, the *Pseudomonas aeruginosa* strain G028 is tolerant to sulfides. The sulfide content in crude oil-containing materials can be selected within a wide range. This is an illustrative example, but does not limit the scope of the invention. According to a preferred embodiment of the invention, the sulfide content, calculated based on sulfur element, is not higher than 200 mg / L, preferably 50-200 mg / L, for example, 80 mg / L, 100 mg / L, 120 mg / L, 140 mg / L, 160 mg / L, or 180 mg / L.

[0041] In this invention, there are no particular limitations on the contact conditions; conventional contact conditions in the art are sufficient. According to a preferred embodiment of the invention, the contact conditions include a temperature of 30-37°C.

[0042] In this invention, the Pseudomonas aeruginosa strain G028 has a wide acid-base tolerance range. According to a preferred embodiment of this invention, the pH of the crude oil-containing material is 7.5-8.5, for example, 7.6, 7.8, 8.0, 8.2, or 8.4.

[0043] The fifth aspect of this invention provides a method for removing oil from associated gas in crude oil, the method comprising:

[0044] (1) Contact the associated gas from crude oil with alkaline solution;

[0045] (2) Mix the liquid product from step (1) with the Pseudomonas aeruginosa strain G028 or the bacterial agent described in this invention.

[0046] In this invention, the alkaline solution concentration can be selected within a wide range, as long as it can absorb the hydrogen sulfide in the associated gas. This is an illustrative example, but does not limit the scope of the invention. According to a preferred embodiment of the invention, the alkaline solution concentration is 30-40 g / L.

[0047] In this invention, the range of types of alkali in the alkaline solution is relatively wide. This is an illustrative example, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the alkali is selected from one or more of sodium hydroxide and sodium bicarbonate.

[0048] In this invention, the flow rate of the associated gas is selected within a wide range, which is illustrative but does not limit the scope of the invention. According to a preferred embodiment of the invention, the flow rate of the associated gas is 40-60 m / s. 3 / h.

[0049] In this invention, the associated gas from crude oil also contains H2S. After being absorbed by the alkaline solution, the H2S is converted into sulfides. The range of types of sulfides that can be selected is relatively wide. This is an illustrative example, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the alkali in the alkaline solution is selected from hydroxides, carbonates, bicarbonates, etc. of group IA metal elements, such as sodium hydroxide and sodium bicarbonate.

[0050] In this invention, there is no particular limitation on the concentration of hydrogen sulfide in associated gas from crude oil, and the content of sulfides in the liquid product can be selected within a wide range. This is an illustrative example, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the sulfide content in the liquid product, calculated by sulfur element, is not higher than 200 mg / L, preferably 50-200 mg / L, for example 80 mg / L, 100 mg / L, 120 mg / L, 140 mg / L, 160 mg / L, or 180 mg / L.

[0051] In this invention, the *Pseudomonas aeruginosa* strain G028 has a wide acid-base tolerance range. The pH range of the liquid product after the *Pseudomonas aeruginosa* strain G028 or the bacterial agent of this invention comes into contact with the associated gas is relatively wide, as long as there is no biotoxicity. According to a preferred embodiment of this invention, the pH of the liquid product is 7.5-8.5, for example, 7.6, 7.8, 8.0, 8.2, or 8.4.

[0052] In this invention, there are no particular limitations on the contact conditions between the associated gas from crude oil and the alkaline solution; conventional contact conditions in the art are sufficient. According to a preferred embodiment of this invention, the contact conditions include a temperature of 30-37°C.

[0053] In this invention, the amount of microbial agent inoculated into the liquid product can be selected within a wide range. According to a preferred embodiment of the invention, the microbial agent is 3%-5% of the total volume of the liquid product, for example, 3%, 3.5%, 4%, or 4.5%. For example, according to one embodiment of the invention, the amount of microbial agent inoculated into the liquid product is 3%-5% of the total volume.

[0054] In this invention, the concentration range of *Pseudomonas aeruginosa* strain G028 in the liquid product is relatively wide, which is illustrative but does not limit the scope of the invention. According to a preferred embodiment of the invention, the concentration of *Pseudomonas aeruginosa* strain G028 in the liquid product is 10... 7 -108 cfu / mL.

[0055] In this invention, there are no particular limitations on the mixing conditions of the liquid product and the bacterial agent; conventional contact conditions in the art are sufficient. According to a preferred embodiment of the present invention, the mixing conditions include a temperature of 30-37°C.

[0056] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims of the present invention.

[0057] In this invention specification and context, the ultraviolet method is used to determine the crude oil content: extraction with petroleum ether is used, and measurement is performed on an ultraviolet spectrophotometer. Standard curves are prepared using standard oil solutions of different concentrations obtained by diluting with petroleum ether.

[0058] In this invention specification and context, the OD value of the bacterial solution is measured using spectrophotometry, and the absorbance of the bacterial solution is measured at a wavelength of 600 nm.

[0059] In the present invention specification and context, including the following embodiments, iodometric titration is used to detect sulfide content.

[0060] In the following examples, the G028 bacterial agent is the product of Pseudomonas aeruginosa strain G028 after being cultured in liquid medium (MgSO4 0.2g, CaCl2 0.02g, KH2PO4 0.8g, K2HPO4 1.2g, NH4NO3 1.2g, FeCl3 0.05g, H2O 500mL, pH 7.5, 0.5wt% crude oil as carbon source) at 30°C.

[0061] In the following examples, the JSHD-2 bacterial agent is the product of *Bacillus thermodenitrificans* JSHD-2 cultured in liquid medium (1.0 g / L Na2NO3, 4 g / L sodium acetate, 1.0 g / L MgSO4, 0.1 g / L FeCl3, 0.1 g / L CaCl2, 1.0 g / L KH2PO4, 0.5 g / L yeast extract) at 30°C.

[0062] Example 1

[0063] Crude oil from Jiangsu oilfield wells was added to 100 mL of culture medium (MgSO4 0.2 g, CaCl2 0.02 g, KH2PO4 0.8 g, K2HPO4 1.2 g, NH4NO3 1.2 g, FeCl3 0.05 g, H2O 500 mL, pH 7.5) until the oil content in the liquid was 10 mg / L. 0.1 mL of a 10% crude oil solution was then added. 10The G028 bacterial agent (cfu / mL) was incubated in a constant temperature incubator at 30°C.

[0064] A blank culture medium was used as a control. The spectrophotometer was zeroed, and small amounts of the cultured liquid were taken after 24h, 48h, and 72h of incubation to determine the oil content and OD600 value. The results showed that after 24h of incubation, the OD600 value of the liquid was 0.910, indicating that G028 grew extensively in the culture medium, and the oil content in the liquid was 0.5 mg / L. After 48h of incubation, the OD600 value reached 0.936, indicating that the G028 cell concentration still increased after 48h of incubation, and the oil content in the water was 0.1 mg / L. After 72h of incubation, the OD value of the liquid was 0.893, and the oil content in the water was 0 mg / L. These results demonstrate that *Pseudomonas aeruginosa* G028 can effectively remove oil from materials containing crude oil.

[0065] Example 2

[0066] (1) The flow rate is 40m 3 A crude oil associated gas of / h is passed into a 30g / L sodium hydroxide solution at a solution temperature of 30℃ to obtain a liquid product containing sulfides. The sulfide content is 50mg / L based on sulfur element, the liquid oil content is 5mg / L, and the pH is 8.2.

[0067] (2) Inoculate the Pseudomonas aeruginosa strain G028 into the liquid product at 3% of the volume of the liquid product from step (1). The concentration of the strain in the inoculated solution is 10. 7 cfu / mL; the inoculated solution was placed in a constant temperature incubator and cultured at 30°C.

[0068] After 72 hours of incubation, the results showed that the crude oil content in the solution was 0 mg / L after treatment with Pseudomonas aeruginosa strain G028. These results indicate that Pseudomonas aeruginosa G028 can effectively remove crude oil from associated gas.

[0069] Example 3

[0070] (1) The flow rate is 50m 3 A crude oil associated gas of / h is passed into a 40g / L sodium bicarbonate solution at a solution temperature of 32℃ to obtain a liquid product containing sulfides, wherein the sulfide content is 120mg / L, the liquid oil content is 10mg / L, and the pH is 8.4.

[0071] (2) Inoculate the liquid product with Pseudomonas aeruginosa strain G028 at 5% of the volume of the liquid product from step (1). The concentration of the strain in the inoculated solution is 10. 8 cfu / mL; the inoculated solution was placed in a constant temperature incubator and cultured at 30°C.

[0072] After 72 hours of incubation, the results showed that the crude oil content in the solution was 0 mg / L after treatment with Pseudomonas aeruginosa strain G028.

[0073] Example 4

[0074] (1) The flow rate is 60m 3 A crude oil associated gas of / h is passed into a 40g / L sodium hydroxide solution at a solution temperature of 32℃ to obtain a liquid product containing sodium sulfide, wherein the sulfide content is 150mg / L, the liquid oil content is 15mg / L, and the pH is 8.5.

[0075] (2) Inoculate the liquid product with Pseudomonas aeruginosa strain G028 at 5% of the volume of the liquid product from step (1). The concentration of the strain in the inoculated solution is 10. 8 cfu / mL; the inoculated solution was placed in a constant temperature incubator and cultured at 30°C.

[0076] After 72 hours of incubation, the results showed that the crude oil content in the solution was 0 mg / L after treatment with Pseudomonas aeruginosa strain G028.

[0077] Example 5

[0078] 0.1 mL of a 100 mL culture medium (0.4 g / L MgSO4, 0.04 g / L CaCl2, 1.6 g / L KH2PO4, 2.4 g / L K2HPO4, 2.4 g / L NH4NO3, 0.1 g / L FeCl3, 0.5 g / L yeast extract) was inoculated with each of the following solutions: 8 CFU / mL G028 bacterial suspension and 0.9 mL of 10 CFU / mL G028 bacterial suspension 8 A JSHD-2 bacterial suspension of CFU / mL was inoculated into 1.0 mL of a 10⁻⁶ CFU / mL culture medium. 8 A JSHD-2 bacterial suspension of cfu / mL was used as a control group and cultured at 30℃ to observe the growth and reproduction of the two bacteria under a common nutrient system.

[0079] A blank culture medium was used as a blank control. The spectrophotometer was zeroed, and small amounts of the cultured liquid were taken after 24h, 48h, and 72h of incubation to measure the OD600 value. The results showed that after 16h of incubation, the OD600 value was 0.690, indicating that the bacteria were in the logarithmic growth phase. A small amount of liquid was centrifuged and Gram-stained for microscopic examination. Most bacteria in the field of view were stained blue-purple, with a few red, indicating significant growth of JSHD-2 strain, and a small amount of G028 also grew. There was no significant difference in the OD600 value (0.675) after 16h of incubation compared to the control group inoculated with JSHD-2 alone. After 24h of incubation, the OD600 value was 0.846, indicating that the bacterial concentration reached its maximum, while the control group's OD600 value was 0.819. These results indicate that there is no significant competition for growth between the two bacteria in the mixed culture, and they can co-grow.

[0080] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A strain of Pseudomonas aeruginosa, G028, characterized in that, The preservation number of this Pseudomonas aeruginosa is CGMCC No. 9039.

2. A microbial agent, characterized in that, The bacterial agent contains the *Pseudomonas aeruginosa* strain G028 as described in claim 1; preferably, the viable count in the bacterial agent is 10. 8 cfu / mL or higher.

3. The application of the Pseudomonas aeruginosa strain G028 according to claim 1 and / or the bacterial agent according to claim 2 in oil removal.

4. A method for removing crude oil, characterized in that, The method includes contacting the Pseudomonas aeruginosa strain G028 of claim 1 and / or the bacterial agent of claim 2 with a crude oil-containing material.

5. The method according to claim 4, wherein, The bacterial agent is 0.1%-5.0% of the total volume of the crude oil-containing material; Preferably, the microbial agent further contains desulfurization strains; Preferably, the desulfurization strain is Geobacillus thermodenitrificans strain JSHD-2 and / or Geobacillus toebii strain JSHD-4; Preferably, the concentration of the *Pseudomonas aeruginosa* strain G028 in the crude oil-containing material is 10. 7 -10 8 cfu / mL.

6. The method according to claim 4 or 5, wherein, In materials containing crude oil, the crude oil content is 5-20 mg / L; Preferably, the crude oil-containing material also contains sulfides, which are selected from sulfides of Group IA metals and / or hydrosulfides of Group IA metals. Preferably, the sulfide content, calculated as sulfur element, is not higher than 200 mg / L, and more preferably 50-200 mg / L.

7. The method according to any one of claims 4-6, wherein, The pH of materials containing crude oil is 7.5-8.5; and / or Contact conditions include a temperature of 30-37℃.

8. A method for removing oil from associated gas of crude oil, characterized in that, The method includes; (1) Contact the associated gas from crude oil with alkaline solution; (2) Mix the liquid product from step (1) with the Pseudomonas aeruginosa strain G028 as described in claim 1 and / or the bacterial agent as described in claim 2.

9. The method according to claim 8, wherein, The concentration of the alkali solution is 30-40 g / L; and / or The associated gas flow velocity is 40-60 m / s. 3 / h; Preferably, the associated gas also contains H2S, which forms sulfides upon contact with alkaline solution; Preferably, the sulfide content in the liquid product, calculated as sulfur element, is not higher than 200 mg / L, and more preferably 50-200 mg / L.

10. The method according to claim 8 or 9, wherein, The pH of the liquid product is 7.5-8.5; and / or Mixing conditions include: a temperature of 30-37°C; and / or The bacterial agent constitutes 3%-5% of the total volume of the liquid product; Preferably, the concentration of the *Pseudomonas aeruginosa* strain G028 in the liquid product is 10. 7 -10 8 cfu / mL.

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