A Malathion-Degrading Bacterium Derived from Tidal Flat and Its Application

Abstract

The present invention discloses a malathion-degrading bacterium derived from tidal flats and its application, which relates to the field of biotechnology. The malathion-degrading bacterium is Ectopseudomonas khazarica FJ5-34-2, which was deposited on November 8, 2024 at the General Microbiology Center of the China National Center for Culture Collection of Microorganisms. The deposit address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, and the deposit number is CGMCC No. 32547. The present invention screened a strain of Ectopseudomonas FJ5-34-2 from tidal flat samples in Beidaihe New Area, Qinhuangdao, Hebei Province. This Ectopseudomonas can effectively degrade malathion, and the degradation rate of 100 mg / L malathion can reach 94.93% within 72 h. The present invention provides a new and effective microorganism for the microbial degradation of malathion, which has great practical significance for alleviating the environmental residues of pesticides.

Description

Technical Field

[0001] The present invention relates to the field of biotechnology, and particularly to a malathion-degrading bacterium derived from tidal flats and its application. Background Art

[0002] With the improvement of farmland productivity, low recovery rates in pesticide processing factories, continuous increases in pesticide usage, and unreasonable pesticide use have led to serious soil pesticide pollution. Pesticides can be classified into organophosphorus, organochlorine, pyrethroid, amide, carbamate, etc. Organophosphorus pesticides (OPP) are one of the most widely used pesticides globally since the ban on organochlorine pesticides.

[0003] After entering the soil, OPP is adsorbed by soil colloids and minerals and remains in the soil for a long time. Its degradation is affected by soil types and plants, with half-lives ranging from a few minutes to several years, and it can also be converted into a stable state and persist in the soil. Due to its high toxicity, OPP seriously endangers the survival of soil microorganisms and animals and disrupts the stability of the soil ecosystem. Although China has effectively alleviated the environmental residues of pesticides through means such as bans, reduced use, and substitution, there are still many pesticides being discharged into the living environment during production practices, and the originally remaining pesticides are also difficult to be effectively degraded, which not only affects the subsequent use of land but also threatens human health and ecological safety. Therefore, the treatment and remediation of soil pollution caused by OPP are still one of the important goals of the current healthy soil action. Malathion is a type of OPP and is a commonly used insecticide in the process of fruit and vegetable cultivation and is also often used as a preservative for grain storage. Although malathion belongs to low-toxicity compounds, long-term unreasonable use will lead to excessive malathion residues in the environment and food, which enter the human body through the enrichment of the food chain and cause damage to the liver and central nervous system by inhibiting the activity of acetylcholinesterase, and severe cases can lead to poisoning and death. Prolonged exposure to an environment containing malathion may also cause complications such as myocarditis, pulmonary edema, and pancreatitis, posing a potential threat to human health.

[0004] The research on the microbial degradation of pesticides began in the 1950s of the 20th century, and a large number of experiments have verified that microbial degradation is the most important way for pesticides to degrade in the environment. The present invention intends to develop new microbial strains to achieve the efficient degradation of malathion. Summary of the Invention

[0005] The purpose of the present invention is to provide a malathion-degrading bacterium derived from tidal flats and its application to solve the problems existing in the above-mentioned prior art. This degrading bacterium can effectively degrade malathion, and the degradation rate can reach 94.93%, which has great practical significance for alleviating the environmental residues of pesticides.

[0006] To achieve the above purpose, the present invention provides the following solutions:

[0007] The present invention provides a malathion-degrading bacterium sourced from the tidal flat. The malathion-degrading bacterium is Ectopseudomonas khazarica FJ5-34-2, which was deposited on November 8, 2024, at the General Microbiological Center of the China Committee for Culture Collection of Microorganisms. The deposit address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, and the deposit number is CGMCC No. 32547.

[0008] The present invention also provides the application of the above-mentioned malathion-degrading bacterium in the preparation of a microbial agent for degrading malathion.

[0009] The present invention also provides a microbial agent for degrading malathion, which includes the above-mentioned malathion-degrading bacterium.

[0010] The present invention also provides the application of the above-mentioned malathion-degrading bacterium in degrading malathion.

[0011] The present invention also provides the application of the above-mentioned microbial agent in degrading malathion.

[0012] The present invention also provides a preparation method of the above-mentioned microbial agent, which includes inoculating the above-mentioned malathion-degrading bacterium into a fermentation medium for fermentation culture to obtain a fermentation broth, and preparing the fermentation broth into the microbial agent.

[0013] Further, the fermentation medium is 2216E liquid medium;

[0014] The 2216E liquid medium includes the following components: tryptone 5 g / L, yeast extract 1 g / L, ferric citrate 0.1 g / L, NaCl 23.477 g / L, Na 2 SO 4 3.917 g / L, MgCl 2 ·6H 2 O 4.981 g / L, CaCl 2 1.102 g / L, NaHCO 3 193 mg / L, KCl 664 mg / L, KBr 6 mg / L, H 3 BO 3 20 mg / L, SrCl 2 24 mg / L, and NaF 3 mg / L.

[0015] Further, the temperature of the fermentation culture is 28 °C.

[0016] Further, the time of the fermentation culture is 10 h.

[0017] The present invention also provides a method for degrading malathion in soil, which includes inoculating the above-mentioned malathion-degrading bacteria into the soil to be degraded and degrading malathion.

[0018] The present invention discloses the following technical effects:

[0019] The present invention screens a strain of Pseudomonas putida in vitro - FJ5-34-2 from a tidal flat sample in Beidaihe New Area, Qinhuangdao, Hebei Province (119°44′53″ E, 39°59′32″ N). This Pseudomonas putida in vitro can effectively degrade malathion, and the degradation rate of 100 mg / L malathion can reach 94.93% within 72 h.

[0020] The present invention provides new effective microorganisms for the microbial degradation of malathion, which has great practical significance for alleviating the environmental residues of pesticides. Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 It is a comparison result diagram of the 16S rDNA sequence of strain FJ5-34-2 in NCBI BLAST;

[0023] Figure 2 It is a result diagram of OrthoANIu (Orthologous Average Nucleotide Identity) analysis;

[0024] Figure 3 It is a phylogenetic tree diagram;

[0025] Figure 4 It is a streaking plate diagram of strain FJ5-34-2;

[0026] Figure 5 It is a scanning electron microscope image of strain FJ5-34-2 after culturing in 2216E liquid medium at 28°C for 10 h;

[0027] Figure 6 It is a scanning electron microscope image of strain FJ5-34-2 after culturing in M1 liquid medium containing 100 mg / L malathion at 28°C for 10 h;

[0028] Figure 7 It is a transmission electron microscope image of strain FJ5-34-2 after culturing in 2216E solid medium at 28°C for 10 h;

[0029] Figure 8 It is a transmission electron micrograph of strain FJ5-34-2 after culturing on a solid medium M1 containing 100 mg / L malathion at 28 °C for 10 h;

[0030] Figure 9 It is the LC / MS detection peak map of the negative control group in Example 2;

[0031] Figure 10 It is the LC / MS detection peak map of the experimental group in Example 2. Detailed implementation manners

[0032] Now, various exemplary implementation manners of the present invention will be described in detail. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics, and implementation schemes of the present invention.

[0033] It should be understood that the terms described in the present invention are only for describing specific implementation manners and are not used to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

[0034] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0035] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific implementation manners of the present invention specification, which are obvious to those skilled in the art. Other implementation manners obtained from the specification of the present invention are obvious to those skilled in the art. The specification and examples of the present invention are only exemplary.

[0036] Regarding the terms "comprising", "including", "having", "containing", etc. used herein, they are all open-ended terms, meaning including but not limited to.

[0037] The experimental materials involved in the following examples are as follows:

[0038] 1. Main reagents

[0039] (1) Malathion mother liquor (concentration: 100 g / L): Prepared by dissolving 1 g of malathion in 10 mL of methanol.

[0040] (2) Artificial seawater: 23.477 g / L of NaCl, 2 SO 4 3.917 g / L of MgCl 2 ·6H 2 O 4.981 g / L of CaCl 2

[0041] 1.102 g / L of NaHCO 3 193 mg / L of KCl, 664 mg / L of KBr, 6 mg / L of H 3 BO 3 20 mg / L of SrCl 2 24 mg / L of NaF.

[0042] (3) 1M Tris-HCl (pH 7.0): Weigh 12.1 g of Tris, dissolve it in deionized water, adjust the pH to 7.0 with concentrated HCl and make up the volume to 100 mL. Autoclave at 121 °C for 20 min and let it stand at room temperature.

[0043] 2. Main culture media

[0044] (1) M1 liquid culture medium: 0.002 wt% yeast extract, 0.1 wt% ammonium sulfate and 1.8 wt% sea salt, dissolved in deionized water, adjust the pH to 7.2 - 7.4 with 1M Tris-HCl (pH 7.0), autoclave at 121 °C for 20 min.

[0045] (2) 2216E liquid culture medium: 5 g of tryptone, 1 g of yeast extract powder and 0.1 g of ferric citrate, make up the volume to 1 L with artificial seawater, autoclave at 121 °C for 20 min.

[0046] (3) The composition of 2216E solid culture medium is as follows: 5 g of tryptone, 1 g of yeast extract powder, 0.1 g of ferric citrate and 18 g of agar, make up the volume to 1000 mL with artificial seawater, autoclave at 121 °C for 20 min.

[0047] Example 1 Strain screening and identification

[0048] 1. Strain screening

[0049] The strain FJ5-34-2 is derived from a tidal flat sample in Beidaihe New Area, Qinhuangdao, Hebei Province (119°44′53″ E, 39°59′32″ N). The isolation process is as follows:

[0050] Weigh 2 g of this sample and place it in a sterile M1 liquid medium containing 25 mg / L malathion. Enrichment culture is carried out in a shaker at 28 °C and 200 rpm. This is the first round of enrichment. After ten days, transfer the enriched culture broth to a sterile M1 liquid medium containing 50 mg / L malathion at a ratio of 1% and continue the enrichment culture under the above conditions for ten days. This is the second round of enrichment; transfer the second-round enriched culture broth to a sterile M1 liquid medium containing 100 mg / L malathion according to the above method and enrich it for ten days. This is the third round of enrichment; transfer the third-round enriched culture broth to a sterile M1 liquid medium containing 150 mg / L malathion and enrich it for ten days. This is the fourth round of enrichment; transfer the fourth-round enriched culture broth to a sterile M1 liquid medium containing 2000 mg / L malathion and enrich it for ten days. This is the fifth round of enrichment.

[0051] Dilute the enriched culture broth of each round and spread it on a 2216E solid medium. After incubating it upside down in an incubator at 28 °C for 24 h, pick a single colony growing on the solid plate and transfer it to 2 mL of sterile 2216E liquid medium for enlarged culture; after culturing for 12 h, amplify the 16S rDNA of the bacteria with primers Eubac-27F and Eubac-1492R, and send the amplified product to Sangon Biotech for sequencing; obtain the 16S rDNA sequence of the screened strain and perform a BLAST comparison in NCBI to obtain the closely related type strain with the highest sequence similarity to the screened strain. The screened strains are named as "enrichment round number - tidal flat sample number - colony serial number picked from this sample". The Pseudomonas bacterium FJ5-34-2 screened in the present invention is the second strain screened from sample No. 34 in the fifth round of enrichment. The screened strain FJ5-34-2 is further screened and purified by streaking on a 2216E solid medium. The purified strain is inoculated into a triangular flask containing 2216E liquid medium and cultured with shaking at 28 °C and 200 rpm for 10 h to obtain a fermentation broth for standby.

[0052] Use the BLAST function in NCBI to compare the 16S rDNA sequence of strain FJ5-34-2 in the 16S ribosomal database, and it is found that the closely related type strain with the highest sequence similarity to the screened strain is Ectopseudomonas khazaricastrain TBZ2 (NR 169334.1), and the sequence similarity is 99.65%, as follows Figure 1 shown. Figure 2Shows the results of OrthoANIu (Orthologous Average Nucleotide Identity) analysis, which is an improved method for calculating ANI (Average Nucleotide Identity) that uses orthologous genes to improve the accuracy and reliability of the calculation. This is a method for comparing the similarity between two genomes, and these results are usually used to determine whether two genomes belong to the same species or subspecies. High OrthoANIu values (usually exceeding 95%) and high coverage usually indicate that the two genomes are very similar and may belong to the same species. The OrthoANIu value between the two genomes is 98.67%, indicating a very high similarity in the orthologous regions of the two genomes and may belong to the same species. DNA-DNA hybridization (DDH) is a laboratory technique used to measure the similarity between two genomes. It is generally considered that a DDH value exceeding 70% indicates that they may belong to the same species, and exceeding 95% may belong to the same subspecies. This formula calculates the proportion of identical nucleotides in the high-scoring segments (HSPs). The results in Table 1 show that the distance is 0.0140 and the DDH estimate is 88.30%, which means that there is an 88.30% probability that the two genomes are of the same species. Through logistic regression analysis, the probability that the DDH value exceeds 70% is 95.19%.

[0053] Table 1 Results of DDH analysis

[0054]

[0055] Figure 3 Is a phylogenetic tree constructed by the NJ method based on the 16S rDNA sequence of strain FJ5-34-2, Pseudomonas strains, and in vitro Pseudomonas and Aquapseudomonas strains; the phylogenetic tree shows that strain FJ5-34-2 forms a tight branch with Pseudomonas khazarica strain TBZ2 (i.e., Ectopseudomonas khazarica strain TBZ2). In summary, the present invention identifies strain FJ5-34-2 as Ectopseudomonas khazarica.

[0056] 16S rDNA sequence of strain FJ5-34-2 (SEQ ID NO.1):

[0057]

[0058] 2. Colony Morphology

[0059] For strain FJ5-34-2, the colony on 2216E solid medium is milky white, opaque, raised, moist, with a milky white halo around it; the colony morphology of FJ5-34-2 is fusiform, with neat edges, smooth and shiny surface, see Figure 4 .

[0060] 3. Observe the differences of strain FJ5-34-2 in 2216E medium and M1 medium containing 100 mg / L by scanning electron microscopy and transmission electron microscopy.

[0061] (1) Scanning Electron Microscopy Observation

[0062] A. Streak-culture strain FJ5-34-2 on 2216E solid medium and incubate at 28 °C for 10 h; separately pick monoclonal colonies into 5 mL of sterile 2216E liquid medium, and incubate at 30 °C for 10 h at 200 rpm, then collect 20 μL - 30 μL of bacterial cells, which are the control group bacterial cells of strain FJ5-34-2; at the same time, transfer the bacterial cells cultured in 2216E medium (calculate the concentration of the bacterial cell culture solution using the absorbance value to make the final concentration OD 600 = 4) to 10 mL of medium containing malathion (100 mg / L) at a ratio of 3%, and incubate at 28 °C at 200 rpm for 10 h, then collect 20 μL - 30 μL of bacterial cells, which are the experimental group bacterial cells.

[0063] B. Wash the above-collected bacterial cells (experimental group and control group of strain FJ5-34-2) 2 times with PBS buffer (pH 7.2), then use 2.5% glutaraldehyde solution to fix the bacterial cells at a volume ratio of 1:10 and treat them overnight at 4 °C.

[0064] C. First centrifuge the above sample solutions, suck out the 2.5% glutaraldehyde fixing solution, and add deionized water to soak the samples for 4 min.

[0065] D. Centrifuge the above sample solutions, suck out the deionized water, and add 50% ethanol solution to soak for 14 min.

[0066] E. Suck out the ethanol solution in the above samples, and add 70% ethanol to soak for 14 min.

[0067] F. Suck out the ethanol solution in the above samples, and add 85% ethanol to soak for 14 min.

[0068] G. Suck out the ethanol solution in the above samples, and add 95% ethanol to soak for 14 min.

[0069] H. Aspirate the ethanol solution from each of the above samples and add 100% ethanol to soak for 15 min.

[0070] I. Perform sputtering gold treatment on the above fixed and dehydrated experimental group and control group samples respectively.

[0071] J. Conduct electron microscopy scanning.

[0072] (2) Transmission electron microscopy observation

[0073] A. Streak-culture the strain FJ5-34-2 on 2216E solid medium and culture it at 28 °C for 10 h; separately pick monoclonal colonies into 5 mL of sterile 2216E liquid medium and culture at 28 °C for 10 h under the condition of 200 rpm. At the same time, take 100 μL of the bacterial liquid cultured in 2216E medium (calculate the concentration of the bacterial liquid of the strain using the absorbance value to make the final concentration OD 600 = 4) and spread it onto 2216E solid medium and M1 solid medium containing malathion (100 mg / L) respectively, and place it in an incubator at 28 °C for overnight culture. Elute the bacteria on 2216E solid medium and M1 solid medium containing malathion (100 mg / L) with 100 μL of sterile water respectively, which are the control group and experimental group bacterial liquids;

[0074] B. Pipette 20 μL of the control group and experimental group bacterial liquids onto a clean sealing film respectively, cover the copper mesh with the film on it, after 2 min, pick up the copper mesh with forceps and absorb the excess control group and experimental group bacterial liquids with filter paper; drop two drops of negative staining solution (1.5% phosphotungstic acid) on another sealing film, and float the copper mesh with the control group and experimental group bacterial liquids facing down on the negative staining solution drops respectively for 2 min;

[0075] C. Pick up the copper mesh with forceps and absorb the excess staining solution with filter paper. After drying, observe it with an electron microscope.

[0076] The scanning electron micrograph of strain FJ5-34-2 after culturing in 2216E liquid medium at 28 °C for 10 h ( Figure 5 ) It can be seen that these bacteria present a rod-shaped morphology, slightly pointed at both ends, with a smooth surface. They exist in the form of clusters, are arranged relatively densely, and the sizes of the bacterial cells are different. The scanning electron micrograph of strain FJ5-34-2 after culturing in M1 liquid medium containing 100 mg / L malathion at 28 °C for 10 h ( Figure 6 ) shows that the bacterial cells are slender and rod-shaped, with a smooth surface, neatly arranged together, and the sizes of the bacterial cells are similar. Figure 7 This is the transmission electron micrograph of strain FJ5-34-2 after culturing on 2216E solid medium at 28 °C for 10 h. At this time, the bacterial cells are small, short rod-shaped, with a smooth surface, and aggregated together; while Figure 8This is a transmission electron micrograph of the bacteria after being cultured in M1 solid culture medium containing 100 mg / L malathion at 28°C for 10 hours. At this time, the bacteria are longer and rod-shaped, but the surface is not smooth and has defects. The three bacteria are almost the same size and are relatively uniform.

[0077] In summary, it can be clearly seen through comparison that there are significant differences in the colony morphology of strain FJ5-34-2 under different conditions. First, in ordinary liquid culture medium, the bacteria present a typical rod-shaped morphology, but in the culture medium containing malathion, some bacteria become more slender. Secondly, the transmission electron microscopy image shows that the bacteria in ordinary solid culture medium are small and have a smooth surface, while in the solid culture medium containing malathion, the length of the bacteria increases and defects appear on the surface. These changes may reflect the differences in the adaptability and survival strategies of strain FJ5-34-2 to different environmental conditions.

[0078] 2. Strain Preservation

[0079] The strain Ectopseudomonas khazarica FJ5-34-2 was deposited in the General Microbiology Center of China Microorganism Culture Collection on November 8, 2024. The deposit address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, and the deposit number is CGMCC No.32547.

[0080] Example 2 Degradation Detection of Malathion

[0081] 1. Main culture medium

[0082] Sea salt optimized culture medium: 0.4g yeast powder, 0.3g glucose, 1g (NH 4 ) 2 SO 4 and 18 g sea salt, dissolved in 1 L distilled water, adjusted pH to 7.0-7.2 with Tris-HCl, and sterilized by high pressure wet heat at 121°C for 20 min.

[0083] 2. Experimental Methods

[0084] 1. In vitro transfer of Pseudomonas bacterial strain FJ5-34-2 to inorganic salt medium

[0085] The purified in vitro Pseudomonas bacterial strain FJ5-34-2 was inoculated into a triangular flask containing 2216E liquid culture medium and cultured at 28°C and 200 rpm for 10 h to obtain a fermentation broth. The obtained fermentation broth was tested for OD by an ultraviolet spectrophotometer. 600 , collect OD 600The fermentation broth with a volume of 5 mL was centrifuged at 3500 rpm for 8 min at room temperature. The supernatant was discarded, and the pellet was resuspended with 1 mL of inorganic salt medium and washed three times for later use. The washed and resuspended fermentation broth was added to 10 mL of inorganic salt liquid medium at a ratio of 1%, which was the experimental group; another 10 mL of inorganic salt liquid medium without adding fermentation broth was the negative control group. Finally, malathion with a stock solution concentration of 20 g / L was added to the experimental group and the negative control group at a ratio of 0.5% to make the final concentration of malathion 100 mg / L. Under the condition of 30 °C, it was cultured with shaking at 200 rpm for 72 h, and the inorganic salt fermentation broth of the experimental group and the negative control group was reserved for later use.

[0086] 2. Extraction of Malathion

[0087] To the inorganic salt culture fermentation broth of the experimental group and the negative control group, 5 mL of methanol was added to each, shaken thoroughly for 1 min, and left to stand at room temperature for 1 - 2 h. Then, 1 mL of the upper organic phase solution was aspirated, centrifuged at 13000 rpm for 1 min, and the supernatant was filtered into a brown bottle.

[0088] 3. Detection of Malathion Degradation

[0089] A liquid chromatography - mass spectrometry (Agilent 1260 / 6460 Triple Quad LC / MS) was used to detect malathion. A C - 18 column (2.1×100 mm, dp = 3.5 μm) was used. The detection conditions were as follows: gradient elution was carried out with 0.1% HCOOH and 2% MeOH in water (solvent A) and pure acetonitrile (solvent B). The injection volume was 10 μL. The initial condition of the gradient elution was 95% A - 5% B, maintained at 95% A - 5% B for 2 min, programmed to 10% A - 90% B within 29 min, and maintained at 10% A - 90% B for 27 min. The total analysis time was 44 min. The malathion content was detected near the retention time of 21.3 min. The degradation rate of malathion was determined according to the difference in peak areas between the experimental group and the negative control group, that is, degradation rate = (peak area of the negative control group - peak area of the experimental group) / peak area of the negative control group.

[0090] III. Experimental Results

[0091] According to Figure 9 and Figure 10The LC / MS detection peak chart after 72 hours of cultivation shows that the malathion characteristic peak appears near 21.3 minutes in both the negative control group and the experimental group. According to the peak chart, the peak area of malathion after 72 hours can be obtained and is listed in Table 2. The peak area of the negative control is 7786802, and the peak area of the experimental group is 395009. The degradation rate of malathion is determined based on the difference in peak areas between the experimental group and the negative control group, that is, degradation rate = (peak area of negative control group - peak area of experimental group) / peak area of negative control group. After calculation, it can be obtained that after 72 hours of cultivation, the malathion degradation rate in the experimental group is as high as 94.93%. This indicates that after 72 hours of cultivation, the malathion in the experimental group is significantly degraded. The strain FJ5-34-2 has a malathion degradation rate of up to 94.93% for 100 mg / L malathion in 72 hours, which has great practical significance for alleviating the environmental residues of pesticides.

[0092] Table 2 LC / MS detection data

[0093] Group Retention time (min) Peak area Degradation rate Negative control group 21.307 7786802 / Experimental group 21.271 395009 94.93％

[0094] The embodiments described above are only descriptions of the preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A malathion-degrading bacterium derived from a tidal flat, characterized in that: The malathion-degrading bacteria is Ectopseudomonas khazarica FJ5-34-2, which was deposited in the General Microbiology Center of China Microorganism Culture Collection Administration on November 8, 2024. The deposit address is No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, and the deposit number is CGMCC No. 32547.

2. Use of the malathion-degrading bacteria as claimed in claim 1 in the preparation of a microbial agent for degrading malathion.

3. A microbial agent for degrading malathion, characterized in that: It includes the malathion-degrading bacteria described in claim 1.

4. Use of the malathion-degrading bacteria as claimed in claim 1 in degrading malathion.

5. Use of the microbial agent as claimed in claim 3 in degrading malathion.

6. A method for preparing the microbial agent according to claim 3, characterized in that: The method comprises the steps of inoculating the malathion-degrading bacteria described in claim 1 into a fermentation medium for fermentation culture to obtain a fermentation liquid, and preparing the fermentation liquid into the microbial agent.

7. The preparation method according to claim 6, characterized in that: The fermentation medium is 2216E liquid medium; The 2216E liquid culture medium includes the following components: 5 g / L tryptone, 1 g / L yeast extract and 0.1 g / L ferric citrate, 23.477 g / L NaCl, 3.917 g / L Na2SO4, 4.981 g / L MgCl2·6H2O, 1.102 g / L CaCl2, 193 mg / L NaHCO3, 664 mg / L KCl, 6 mg / L KBr, 20 mg / L H3BO3, 24 mg / L SrCl2 and 3 mg / L NaF.

8. The preparation method according to claim 6, characterized in that: The fermentation temperature was 28°C.

9. The preparation method according to claim 6, characterized in that: The fermentation culture time is 10 hours.

10. A method for degrading malathion in soil, characterized in that: The method comprises the steps of inoculating the malathion-degrading bacteria described in claim 1 into the soil to be degraded to degrade the malathion.

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