Mudflat-sourced malathion degrading bacterium and application thereof

Abstract

The invention discloses a mud flat-derived malathion degrading bacterium and application thereof, and relates to the technical field of biology. The malathion degrading bacterium is Ectopseudomonas khazarica FJ5-34-2, and is preserved in the China General Microbiological Culture Collection Center on November 8, 2024, the preservation address is No.3, No.1 yard, Beichen West Road, Chaoyang District, Beijing, and the preservation number is CGMCC No.32547. The malathion degrading bacterium has the advantages that the malathion degrading bacterium can be used for degrading malathion; according to the invention, an in-vitro pseudomonas strain FJ5-34-2 is screened from a mud flat sample in a new area of Northern Daihe River in Qinhuangdao, Hebei province. The in-vitro pseudomonas can effectively degrade malathion, and the degradation rate of 100 mg / L malathion within 72 hours can reach 94.93%. The invention provides a new effective microorganism for microbial degradation of malathion, which has great practical significance for relieving environmental residues of pesticides.

Description

Technical Field

[0001] The invention relates to the field of biotechnology, in particular to a malathion-degrading bacterium derived from a tidal flat and application thereof. Background Art

[0002] With the improvement of farmland productivity, the low recycling rate of pesticide processing factories, the continuous increase in pesticide use and the irrational use of pesticides have led to serious soil pesticide pollution. Pesticides can be divided into organophosphorus, organochlorine, pyrethroids, amides, carbamates, etc. Organophosphorus pesticides (OPP) are one of the most widely used pesticides in the world since the ban on organochlorine pesticides.

[0003] After OPP enters the soil, it is adsorbed by soil colloids and minerals and retained for a long time. Its degradation is affected by soil type and plants, with a half-life ranging from a few minutes to a few years. 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 destroys the stability of the soil ecosystem. Although my country has effectively alleviated the environmental residues of pesticides by means of prohibition, less use, and substitution, many pesticides are still discharged into the living environment during production practice, and the original residual pesticides are difficult to be effectively degraded, which not only affects the subsequent use of land, but also threatens human health and ecological security. Therefore, the control and remediation of soil pollution caused by OPP is still one of the important goals of the current healthy soil action. Malathion is a type of OPP. It is a commonly used insecticide in the process of fruit and vegetable cultivation and is also often used as a protective agent for grain storage. Although malathion is a low-toxic compound, its long-term unreasonable use will lead to excessive malathion residues in the environment and food, and enter the human body through enrichment in the food chain. By inhibiting the activity of acetylcholinesterase, it causes damage to the liver and central nervous system, and can lead to poisoning and death in severe cases. Long-term 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 pesticide microbial degradation began in the 1950s, 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 efficient degradation of malathion. Summary of the invention

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

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

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

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

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

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

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

[0012] The present invention also provides a method for preparing the above-mentioned microbial agent, comprising the steps of inoculating the above-mentioned malathion-degrading bacteria into a fermentation medium for fermentation culture to obtain a fermentation liquid, and preparing the fermentation liquid into the microbial agent.

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

[0014] 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.

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

[0016] Furthermore, the fermentation culture time is 10 hours.

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

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

[0019] The invention screens an in vitro pseudomonad strain, FJ5-34-2, from a tidal flat sample in Beidaihe New District, Qinhuangdao, Hebei Province (119°44′53″ east longitude and 39°59′32″ north latitude). The in vitro pseudomonad strain can effectively degrade malathion, and the degradation rate of 100 mg / L malathion can reach 94.93% within 72 hours.

[0020] The present invention provides new effective microorganisms for microbial degradation of malathion, which has great practical significance for alleviating the environmental residues of pesticides. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

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

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

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

[0025] Figure 4 This is the plate streak pattern of strain FJ5-34-2;

[0026] Figure 5 This is a scanning electron micrograph of strain FJ5-34-2 after being cultured in 2216E liquid medium at 28°C for 10 h;

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

[0028] Figure 7 This is the transmission electron micrograph of strain FJ5-34-2 after being cultured in 2216E solid medium at 28°C for 10 h;

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

[0030] Fig. 9The LC / MS peak diagram of the negative control group in Example 2;

[0031] Fig.10 This is the LC / MS detection peak diagram of the experimental group in Example 2. DETAILED DESCRIPTION

[0032] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0033] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0034] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may 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 associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0035] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0036] The words “include,” “including,” “have,” “contain,” etc. used in this document are 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 stock solution (concentration 100 g / L): Dissolve 1 g of malathion in 10 mL of methanol.

[0040] (2) Artificial seawater: NaCl 23.477 g / L, Na2SO4 3.917 g / L, MgCl2·6H2O 4.981 g / L, CaCl2

[0041] 1.102g / L, NaHCO3193 mg / L, KCl 664mg / L, KBr 6mg / L, H3BO320 mg / L, SrCl224 mg / L and NaF 3mg / L.

[0042] (3) 1 M Tris-HCl (pH 7.0): Weigh 12.1 g of Tris and dissolve it in deionized water. Adjust the pH to 7.0 with concentrated HCl and make up to 100 mL. Sterilize by high pressure wet heat at 121°C for 20 min and leave at room temperature.

[0043] 2. Main culture medium

[0044] (1) M1 liquid medium: 0.002 wt% yeast extract, 0.1 wt% ammonium sulfate and 1.8 wt% sea salt were dissolved in deionized water, the pH was adjusted to 7.2-7.4 with 1 M Tris-HCl (pH 7.0), and sterilized by high pressure wet heat at 121°C for 20 min.

[0045] (2) 2216E liquid culture medium: 5 g of tryptone, 1 g of yeast extract, and 0.1 g of ferric citrate, dilute to 1 L with artificial seawater, and sterilize by high pressure wet heat at 121°C for 20 min.

[0046] (3) 2216E solid medium was composed of 5 g of tryptone, 1 g of yeast extract, 0.1 g of ferric citrate, and 18 g of agar. The volume was made up to 1000 mL with artificial seawater and sterilized by high pressure wet heat at 121°C for 20 min.

[0047] Example 1 Strain Screening and Identification

[0048] 1. Strain Screening

[0049] Strain FJ5-34-2 originated from a tidal flat sample in Beidaihe New District, Qinhuangdao, Hebei Province (119°44′53″E 39°59′32″N), and the isolation process was as follows:

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

[0051] Each round of enrichment culture solution was diluted and spread on 2216E solid culture medium, placed in an incubator at 28°C and inverted for 24 hours, and then single colonies grown on the solid plate were picked and expanded in 2mL sterile 2216E liquid culture medium; after 12 hours of culture, the 16S rDNA of the bacteria was amplified with primers Eubac-27F and Eubac-1492R, and the amplified products were sent to Sangon Biotech for sequencing; the 16S rDNA sequence of the screened bacteria was obtained, and BLAST comparison was performed in NCBI to obtain the closely related model strain with the highest sequence similarity to the screened strain. The screened strains were named "enrichment round number-beach sample number-colony number of the sample", and the Pseudomonas bacteria FJ5-34-2 screened by the present invention was the second strain screened from sample No. 34 in the fifth round of enrichment. The screened FJ5-34-2 strain was then streaked and purified on 2216E solid culture medium. The purified strain was inoculated into a conical flask filled with 2216E liquid culture medium and cultured at 28°C and 200rpm for 10 hours to obtain a fermentation broth for later use.

[0052] The 16S rDNA sequence of strain FJ5-34-2 was compared with the 16S ribosomal database using the BLAST function in NCBI, and the closely related model strain with the highest sequence similarity to the screened strain was Ectopseudomonas khazarica strain TBZ2 (NR 169334.1), with a sequence similarity of 99.65%, as follows Figure 1 shown. Figure 2Results of OrthoANIu (Orthologous Average Nucleotide Identity) analysis are shown. OrthoANIu is an improved ANI (Average Nucleotide Identity) calculation method that uses orthologous genes to improve the accuracy and reliability of the calculation. This is a method used to compare the similarity between two genomes. These results are often used to determine whether two genomes belong to the same species or subspecies. High OrthoANIu values ​​(usually over 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 that the two genomes are very similar in the orthologous regions 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 believed that DDH values ​​over 70% indicate that they may belong to the same species, and over 95% may belong to the same subspecies. This formula calculates the proportion of identical nucleotides in high-scoring fragments (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 the same species. Through logistic regression analysis, the probability that the DDH value exceeds 70% is 95.19%.

[0053] Table 1 DDH analysis results

[0054]

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

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

[0057]

[0058] 2. Colony morphology

[0059] The colonies of strain FJ5-34-2 on 2216E solid medium are milky white, opaque protuberances, moist, and surrounded by a milky white halo; the colonies of FJ5-34-2 are fusiform, with neat edges and a smooth and shiny surface. Figure 4 .

[0060] 3. Scanning electron microscopy and transmission electron microscopy were used to observe the differences between strain FJ5-34-2 in 2216E medium and M1 medium containing 100 mg / L.

[0061] (1) Scanning electron microscopy observation

[0062] A. The strain FJ5-34-2 was streaked in 2216E solid medium and cultured at 28°C for 10 h; single clones were picked and added to 5 mL of sterile 2216E liquid medium, cultured at 200 rpm and 30°C for 10 h, and 20 μL-30 μL of bacteria were collected, which were the control group of strain FJ5-34-2; at the same time, the bacteria cultured in 2216E medium (the concentration of the strain culture solution was calculated using the absorbance value, and the final concentration was OD 600 =4) The culture medium was transferred to 10 mL of culture medium containing malathion (100 mg / L) at a ratio of 3%, cultured at 200 rpm and 28°C for 10 h, and 20 μL to 30 μL of the cells were collected as the cells of the experimental group.

[0063] B. After washing the collected bacteria (experimental group and control group of strain FJ5-34-2) twice with PBS buffer (pH 7.2), fix the bacteria with 2.5% glutaraldehyde solution at a volume ratio of 1:10 and treat at 4°C overnight.

[0064] C. First, centrifuge the above sample solutions, aspirate out the 2.5% glutaraldehyde fixative, and add deionized water to soak the samples for 4 minutes.

[0065] D. Centrifuge the above sample solutions, aspirate the deionized water, add 50% ethanol solution and soak for 14 minutes.

[0066] E. Aspirate the ethanol solution from the above samples and add 70% ethanol to soak for 14 minutes.

[0067] F. Aspirate the ethanol solution from the above samples and add 85% ethanol to soak for 14 minutes.

[0068] G. Aspirate the ethanol solution from the above samples and add 95% ethanol to soak for 14 minutes.

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

[0070] I. The fixed and dehydrated samples of the experimental group and the control group were subjected to gold spraying treatment respectively.

[0071] J. Perform electron microscopy scanning.

[0072] (2) Transmission electron microscopy observation

[0073] A. Streak strain FJ5-34-2 in 2216E solid medium and culture at 28°C for 10 hours; pick single clones and transfer them to 5 mL of sterile 2216E liquid medium and culture at 200 rpm at 28°C for 10 hours. At the same time, take the bacterial solution cultured in 2216E medium (calculate the concentration of the strain culture solution using the absorbance value, so that the final concentration is OD 600 =4) 100 μL was spread on 2216E solid medium and M1 solid medium containing malathion (100 mg / L), respectively, and cultured in a 28°C incubator overnight. 100 μL of sterile water was used to wash off the bacteria on 2216E solid medium and M1 solid medium containing malathion (100 mg / L), respectively, which were the bacterial solutions of the control group and the experimental group;

[0074] B. Pipette 20 μL of the bacterial solution of the control group and the experimental group onto a clean sealing film, and cover the copper mesh with the film on it. After 2 minutes, pick up the copper mesh with tweezers and absorb the excess bacterial solution of the control group and the experimental group 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 bacterial solution of the control group and the experimental group facing down on the negative staining solution drops, and stain for 2 minutes;

[0075] C. Pick up the copper mesh with tweezers, absorb the excess dye with filter paper, and observe it with an electron microscope after it dries.

[0076] SEM image of strain FJ5-34-2 after being cultured in 2216E liquid medium at 28℃ for 10h ( Figure 5 ) It can be seen that these bacteria are rod-shaped, with slightly pointed ends and smooth surfaces. They exist in clusters, are densely arranged, and have different sizes. SEM images of strain FJ5-34-2 after being cultured in liquid medium containing 100 mg / L malathion at 28°C for 10 hours ( Figure 6 ) showed that the bacteria were slender and rod-shaped with a smooth surface, neatly arranged together, and of similar size. Figure 7 This is a transmission electron micrograph of strain FJ5-34-2 after being cultured in 2216E solid medium at 28°C for 10 hours. At this time, the bacteria are small, short rod-shaped, smooth on the surface, and aggregated together; 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: Dissolve 0.4 g yeast powder, 0.3 g glucose, 1 g (NH4)2SO4 and 18 g sea salt in 1 L distilled water, adjust the pH to 7.0-7.2 with Tris-HCl, and sterilize 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 600=5 was centrifuged at room temperature and 3500rpm for 8min, the supernatant was discarded, and the mixture was resuspended with 1mL of inorganic salt medium, washed 3 times, and set aside. The washed and resuspended fermentation liquid was added to 10mL of inorganic salt liquid medium at a ratio of 1%, which was the experimental group; no fermentation liquid was added to another 10mL of inorganic salt liquid medium, which was the negative control group; finally, 20g / L malathion mother liquid concentration was added to the experimental group and the negative control group at 0.5%, so that the final concentration of malathion was 100mg / L, and the culture was shaken at 200rpm for 72h at 30℃, and the inorganic salt fermentation liquid of the experimental group and the negative control group was set aside.

[0086] 2. Malathion Extraction

[0087] Add 5 mL of methanol to the inorganic salt culture fermentation broth of the experimental group and the negative control group, shake thoroughly for 1 min, let stand for 1-2 h at room temperature, absorb 1 mL of the upper organic phase solution, centrifuge at 13000 rpm for 1 min, and filter the supernatant into a brown bottle.

[0088] 3. Malathion degradation detection

[0089] Malathion was detected by liquid chromatography-mass spectrometry (Agilent 1260 / 6460 Triple Quad LC / MS) using a C-18 column (2.1×100 mm, dp=3.5 μm) under the following detection conditions: gradient elution with 0.1% HCOOH and 2% MeOH in water (solvent A) and pure acetonitrile (solvent B), injection volume of 10 μL, gradient elution. The conditions were initially 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 around the retention time of 21.3 min, and the malathion degradation rate was determined based on the difference in peak area between the experimental group and the negative control group, i.e., degradation rate=(negative control group peak area-experimental group peak area) / negative control group peak area.

[0090] 3. Experimental Results

[0091] according to Fig. 9 and Fig.10The LC / MS peak graph after 72 hours of cultivation showed that the characteristic peak of malathion appeared near 21.3min in both the negative control group and the experimental group. According to the peak graph, the peak area of ​​malathion after 72 hours was obtained, which is listed in Table 2. The peak area of ​​the negative control group was 7786802, and the peak area of ​​the experimental group was 395009. The degradation rate of malathion was determined according to the difference between the peak areas of the experimental group and the negative control group, that is, the degradation rate = (peak area of ​​the negative control group - peak area of ​​the experimental group) / peak area of ​​the negative control group. After calculation, it was found that after 72 hours of cultivation, the degradation rate of malathion in the experimental group was as high as 94.93%. It shows that after 72 hours of cultivation, the malathion in the experimental group was significantly degraded. The degradation rate of strain FJ5-34-2 for 100mg / L malathion was as high as 94.93% in 72 hours, which has great practical significance for alleviating the environmental residue 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 modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all 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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