Efficient detoxification of pseudoxanthomonas to ochratoxin A and application of pseudoxanthomonas

Abstract

The invention relates to the technical field of microorganisms, and discloses efficient detoxification of a strain of pseudoxanthomonas to ochratoxin A and application of the strain of pseudoxanthomonas to the ochratoxin A. A strain of OTA efficient detoxification strain pseudoxanthomonas X-22 is screened out, and the pseudoxanthomonas X-22 can reduce 50 mu g / mL of OTA (10000 times of the national standard) to 0 within 70 min. The strain is mainly used for performing biological detoxification on OTA through intracellular enzyme, and a detoxification product is OTalpha with extremely low toxicity. The optimal growth conditions of the pseudoxanthomonas X-22 are as follows: 1.5 wt% of glucose is added into a basic culture medium as a carbon source, 1.5 wt% of yeast extract is added into the basic culture medium as a nitrogen source, the pH value of the culture medium is adjusted to 7.5, and the culture temperature is 37 DEG C. The OTA detoxification strain pseudoxanthomonas X-22 is applied to fermentation detoxification of polluted corn and oat, the detoxification rates of the corn and the oat are 61.29% and 97.26% respectively, OTA detoxification strain resources are enriched, and a theoretical basis is provided for application of a biological detoxification technology in the corn and the oat.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of microbial technology, and particularly relates to a Pseudomonas sp., a microbial preparation and high-efficiency detoxification of ochratoxin A by the microbial preparation. BACKGROUND

[0002] Ochratoxin A (OTA) is a secondary metabolite produced by Aspergillus and Penicillium fungi. OTA is highly toxic and carcinogenic, seriously threatens food safety and endangers human and animal health. The residual limit of OTA in food is less than 10 μg / kg. Therefore, it is of great practical significance to establish a detoxification technology that is efficient, low-cost and does not cause secondary pollution.

[0003] In the prior art, the main methods for detoxification of OTA are physical detoxification, chemical detoxification and biological detoxification. Physical detoxification methods include heating and extrusion, adsorption, irradiation, cold plasma and pulsed electric field technology. Among them, heating and extrusion and adsorption are difficult to completely remove OTA and may cause loss of nutritional quality. Although irradiation, cold plasma and pulsed electric field treatment can quickly degrade OTA and have little effect on product quality, these methods require some professional equipment, thus limiting their application.

[0004] Chemical detoxification has been widely used in food production, processing and storage. Chemical detoxification removes OTA by destroying its toxic groups or changing its solubility. Although chemical detoxification has certain effects, chemical treatment may produce new toxic and harmful substances, destroy the nutritional ingredients of food, and misuse of chemicals may also harm the ecological environment and human body.

[0005] With the continuous improvement of public awareness of environmental protection and food safety, biological detoxification has become the main means for detoxification of OTA in food and feed due to its advantages of high efficiency, low cost, low side effects and environmental friendliness. SUMMARY

[0006] The present application aims to provide a Pseudomonas sp. that can efficiently detoxify ochratoxin A (OTA) and inhibit the growth and toxin production of ochratoxin.

[0007] Another object of the present application is to use the Pseudomonas sp. to prepare various detoxification products of ochratoxin A.

[0008] To achieve the above objects, the present application adopts the following technical solutions.

[0009] The application provides a Pseudoxanthomonas sp. which has been preserved in Guangdong Microbial Culture Collection Center (GDMCC) on October 24, 2025, and the address of the center is: No. 59, Building 5, 100, Martyr Middle Road, Yuexiu District, Guangzhou, Guangdong Province (Guangdong Provincial Academy of Microbiology), and the preservation number is GDMCC 67026.

[0010] According to 16S rDNA amplification and sequencing analysis, the strain with the preservation number GDMCC 67026 has the following gene sequence number:

[0011] As in the case of other organisms, the Pseudoxanthomonas provided by the present application is still prone to variation. Therefore, mutant strains of the strain can be obtained using physical and chemical mutagenesis methods known in the art. As long as these mutant strains retain the characteristic of ochratoxin A detoxification ability, they also belong to the part of the present application.

[0012] Further, the present application provides a biological agent capable of degrading ochratoxin A, which takes Pseudoxanthomonas sp. as the active ingredient, and the preservation number of the Pseudoxanthomonas sp. is GDMCC No: 67026. The biological agent is in liquid or solid form.

[0013] More specifically, the active ingredient is Pseudoxanthomonas bacterial liquid obtained by activation and multi-stage expansion, Pseudoxanthomonas bacterial suspension obtained by resuspending the bacterial body with sterile PBS buffer after removing the supernatant of the bacterial liquid, or cell contents obtained by crushing and filtering the bacterial suspension.

[0014] The preparation method of the biological detoxification agent comprises the following steps: activating the Pseudoxanthomonas with the preservation number of GDMCC No: 67026, multi-stage expansion, collecting the fermentation culture when the bacterial body is in the stable phase, and preparing a liquid biological detoxification agent; or activating the Pseudoxanthomonas with the preservation number of GDMCC No: 67026, multi-stage expansion, collecting the fermentation liquid when the bacterial body is in the stable phase, collecting the bacterial body by centrifugation and crushing to obtain cell contents, and preparing a liquid biological detoxification agent; or activating the Pseudoxanthomonas with the preservation number of GDMCC No: 67026, multi-stage expansion, collecting the fermentation liquid when the bacterial body is in the stable phase, collecting the bacterial body by centrifugation to prepare a solid biological detoxification agent; or activating the Pseudoxanthomonas with the preservation number of GDMCC No: 67026, multi-stage expansion, collecting the fermentation liquid when the bacterial body is in the stable phase, collecting the bacterial body by centrifugation and crushing to obtain cell contents, and preparing a solid biological detoxification agent.

[0015] The present application also includes the step of preparing a liquid biological detoxification agent into a solid biological detoxification agent.

[0016] In addition, the present application also provides the use of the Pseudoxanthomonas as described above in degrading ochratoxin A.

[0017] The present application also provides the use of the biological detoxification agent as described above in degrading ochratoxin A.

[0018] This invention also provides the application of *Xanthomonas pseudoepiplocinus* as described above for the detoxification of OTA in contaminated corn and oats.

[0019] The present invention also provides the application of the biological detoxifier described above for the detoxification of OTA in contaminated corn and oats.

[0020] Some other beneficial effects of the present invention will become more apparent in the following description or may be learned through actual production. Attached Figure Description

[0021] Figure 1 The image shows the colony morphology of Xanthomonas pseudoxanthomonas X-22.

[0022] Figure 2 The image shown is a microscopic staining image of Xanthomonas pseudoxanthomonas X-22.

[0023] Figure 3 The image shown is an electron microscope scan of Xanthomonas pseudoxanthomonas X-22.

[0024] Figure 4 The image shown is an electrophoresis diagram of 16S rDNA PCR amplification of Xanthomonas pseudoxanthomonas X-22.

[0025] Figure 5 The image shows a phylogenetic tree of 16S rDNA from Xanthomonas pseudoxanthomonas X-22.

[0026] Figure 6 The figure shows the standard curve for OTA.

[0027] Figure 7 The figure shows the HPLC chromatogram of detoxified OTA from Xanthomonas pseudoxanthomonas X-22.

[0028] Figure 8 The figure shows the detoxification effect of Pseudomonas X-22 on different concentrations of OTA; where a represents an OTA concentration of 5 μg / mL; b represents an OTA concentration of 10 μg / mL; c represents an OTA concentration of 20 μg / mL; and d represents an OTA concentration of 50 μg / mL.

[0029] Figure 9 The figure shows the OTA detoxification curve of Xanthomonas pseudoxanthomonas X-22.

[0030] Figure 10 The image shows the detoxification effect of Xanthomonas pseudoepiplocinus X-22 on OTA in corn and oats.

[0031] Figure 11 The figures shown are HPLC chromatograms of OTA detoxification products, where a is the HPLC chromatogram of OTA standard; b is the HPLC chromatogram of OTα standard; c is the HPLC chromatogram before detoxification; and d is the HPLC chromatogram after detoxification.

[0032] Figure 12 The image shows the LC-MS chromatograms of the OTA detoxification products, where a is the OTα positive ion mode extracted ion chromatogram; b is the positive ion mode MS1 chromatogram; and c is the positive ion mode MS2 chromatogram. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0034] This invention screened a highly efficient OTA detoxifying bacterium, *Xanthomonas pseudoxanthomonas* X-22, which can reduce OTA from 50 μg / mL (10,000 times the national standard) to 0 within 70 minutes. The strain primarily detoxifies OTA through intracellular enzymes, producing OTα, a substance with extremely low toxicity.

[0035] The optimal growth conditions for Xanthomonas pseudoepiploxum X-22 are as follows: 1.5 wt% glucose as a carbon source and 1.5 wt% yeast extract as a nitrogen source are added to the basal medium, the pH of the medium is adjusted to 7.5, and the culture temperature is 37℃.

[0036] The application of Xanthomonas pseudoxanthomonas X-22 in fermentation to detoxify contaminated corn and oats resulted in OTA detoxification rates of 61.29% and 97.26% for corn and oats, respectively. This enriched the OTA detoxification strain resources and provided a theoretical basis for the application of biological detoxification technology in corn and oats.

[0037] Example 1.

[0038] Screening and identification of OTA-efficient virus-removing bacteria.

[0039] 1.1 Experimental methods.

[0040] 1.1.1 Sample.

[0041] Soil samples were collected from farmland in Foshan City, Guangdong Province; water samples were collected from a reservoir in Foshan City, Guangdong Province; and corn soaking solution samples were stored in our laboratory. All samples were sealed in sterile sampling bags after collection and stored at 4°C for later use.

[0042] 1.1.2 Bioaccumulation.

[0043] Add 10g of sample to 90mL of LB liquid medium and incubate at 37℃ with shaking at 180r / min for 24h. Take 10mL of culture medium, centrifuge at 5000r / min for 5min, and take the supernatant for 10-fold serial dilution to 10. -5Spread 200 μL of the diluted solution onto LB agar plates and incubate upside down at 37°C for 24 h. Isolate single colonies based on differences in colony morphology. Repeat streak purification 5 times. Mix the purified colonies with 70% water content glycerol and store at -80°C for later use.

[0044] 1.1.3 Screening of OTA-efficient detoxifying bacteria.

[0045] After activating the purified colonies on LB agar, single colonies were picked and cultured overnight on LB liquid medium. Then, they were transferred to fresh LB medium at a 1 wt% inoculation rate and cultured until OD500. 600 =0.6~0.8 for later use. The cultured bacterial solution and OTA were co-incubated in a constant temperature shaking incubator at 37℃ and 180 rpm for 48 h, with a final OTA concentration of 2 μg / mL in the bacterial solution-OTA system. LB medium containing the same concentration of OTA was used as a blank control. After incubation, OTA was extracted, and the OTA content was detected by HPLC to screen for strains with OTA detoxification capabilities. Strains with a detoxification rate exceeding 80% were cultured to OD200. 600 After adding 0.6–0.8 μg of OTA, the culture was co-incubated with 5 μg / mL OTA in a constant temperature shaker at 37°C and 180 rpm for 48 h. LB medium containing the same concentration of OTA served as a blank control. After incubation, OTA was extracted, and the OTA content was detected by HPLC. Finally, highly efficient OTA-detoxifying bacteria were screened.

[0046] Specifically, different single colonies were isolated from the samples based on their morphology, and their OTA detoxification ability was determined. In this experiment, a total of 128 strains were isolated from the samples, of which 22 strains showed detoxification of 2 μg / mL OTA within 48 hours. Four of these strains achieved a detoxification rate exceeding 80%. These four strains with good detoxification ability were further screened and co-incubated with 5 μg / mL OTA for 48 hours. The results showed that strain X-22 exhibited stable and optimal detoxification, completely detoxifying 5 μg / mL OTA within 48 hours. Therefore, strain X-22 was selected as the most efficient OTA detoxifying bacterium.

[0047] 1.2 Morphological identification of OTA-efficient virus-detoxifying bacteria.

[0048] 1.2.1 Morphological identification of strain X-22.

[0049] 1) The selected OTA high-efficiency virus-free bacteria were taken out of the -80℃ freezer and activated on LB agar medium. Once a single colony grew, one colony was picked and streaked onto LB agar medium. The colony was then incubated upside down in a 37℃ constant temperature and humidity incubator for 24 hours, and its morphological characteristics were observed. For example... Figure 1As shown, after 24 hours of culture on LB agar medium, the single colonies formed are light yellow, nearly round, raised, with neat edges, translucent, relatively moist, and glossy.

[0050] 2) Prepare slides using Gram staining and observe bacterial morphology under an upright biological microscope. For example... Figure 2 As shown, the colony morphology of strain X-22 under an upright biological microscope staining is Gram-negative.

[0051] 3) Scanning electron microscopy sample preparation: After collecting the bacterial cells, fix them with 2.5wt% glutaraldehyde at 4℃ for 24h, wash twice with PBS, dehydrate with distilled water and graded ethanol for 15min each, dry and spray with gold before microscopic examination.

[0052] Scanning electron microscope, such as Figure 3 As shown, the bacteria are short rod-shaped and measure 0.2–0.3 × 1.5–2.0 μm in size.

[0053] 1.2.2 Physiological and biochemical identification of strain X-22.

[0054] Physiological and biochemical identification was performed with reference to Bergey's Manual of Bacterial Identification, Ninth Edition and the Manual of Systematic Identification of Common Bacteria. The results are shown in Table 1.

[0055] Table 1. Physiological and biochemical characteristics of strain X-22.

[0056]

[0057] As shown in Table 1, the physiological and biochemical characteristics of strain X-22 indicate that it can utilize fructose, xylose, sucrose, maltose, glucose, cellobiose, and arabinose, but cannot utilize inulin, sucrose, galactose, sorbitol, and mannitol.

[0058] 1.2.3 Molecular identification of OTA-efficient detoxifying bacteria.

[0059] PCR amplification was performed using DNA from strain X-22 as a template. The amplification results are as follows: Figure 4 As shown, the bands are bright and clear, with high specificity, and the 16S rDNA amplification fragment is approximately 1500bp.

[0060] The 16S rDNA sequence of strain X-22 is 1484 bp in length. The 16S rDNA sequence of strain X-22 was analyzed by BLAST in NCBI and compared with the GenBank database to construct a phylogenetic tree. The results are as follows: Figure 5As shown, the 16S rDNA sequence of strain X-22 showed the highest homology (99.93%) with that of *Pseudoxanthomonas* sp. Based on comprehensive analysis of the 16S rDNA sequence of strain X-22, combined with morphological and physiological / biochemical results, strain X-22 was identified as *Pseudoxanthomonas* sp. X-22.

[0061] Example 2.

[0062] Extraction and HPLC detection of OTA.

[0063] Add 3 times the volume of methanol to the fermentation broth, vortex for 5 min, centrifuge at 10000 r / min for 10 min, and filter the supernatant through a 0.22 μm filter membrane for HPLC analysis.

[0064] HPLC detection conditions: Agilent 1260 system, FLD detector, Zorbax SB-C18 column (250 mm × 4.6 mm, 5 μm); mobile phase: acetonitrile / water / acetic acid (99:99:2, v / v / v); flow rate: 1.00 mL / min; column temperature: 30 °C; injection volume: 10 μL; detection wavelength: Ex 333 nm, Em 460 nm; isocratic elution for 15 min.

[0065] OTA Standard Curve: OTA was diluted with chromatographic grade methanol to concentrations of 0.1 μg / mL, 0.5 μg / mL, 1 μg / mL, 2 μg / mL, 5 μg / mL, 10 μg / mL, 20 μg / mL, 50 μg / mL, and 100 μg / mL. HPLC analysis yielded a standard curve of y = 102.28x + 20.61, with R² = 0.9994. Figure 6 As shown, x represents the OTA concentration (μg / mL), y represents the peak area (mv·s), and the standard curve shows good linearity in the concentration range of 0.10–100.00 μg / mL.

[0066] The formula for OTA detoxification rate is: Y = X0 - X1 / X0 × 100%.

[0067] In the formula: Y is the detoxification rate; X0 is the OTA concentration in the blank control group; X1 is the OTA concentration in the experimental group.

[0068] Example 3.

[0069] Detoxification effect of strain X-22 on OTA.

[0070] Strain X-22 was inoculated into LB medium with a final OTA concentration of 5 μg / mL. After incubation at 37℃ and 180 rpm for 48 h using a constant temperature shaker, the OTA content was detected by HPLC. The results are as follows:Figure 7 As shown, the OTA elution time was around 11 min. Compared with the blank control group, after incubation of strain X-22 with OTA for 48 h, no peak was detected at the OTA elution position around 11 min, indicating that strain X-22 achieved a 100% detoxification rate for 5 μg / mL OTA within 48 h, demonstrating that strain X-22 has a highly efficient OTA detoxification ability.

[0071] The concentration of OTA was increased sequentially to 10 μg / mL, 20 μg / mL, and 50 μg / mL, and then incubated with *Xanthomonas pseudoepiplo* X-22 in a constant temperature shaking incubator at 37℃ and 180 rpm for 48 h. The results showed that the strain could completely detoxify OTA at 50 μg / mL within 48 h. Figure 8 As shown.

[0072] The detoxification effect of OTA by *Xanthomonas pseudoxanthomonas* X-22 was investigated using a final concentration of 50 μg / mL. The strain and OTA at a final concentration of 50 μg / mL were mixed and incubated for 120 min, with samples taken every 10 min. The results are shown below. Figure 9 As shown, *Xanthomonas pseudoxanthomonas* X-22 achieved a 90.18% detoxification rate of OTA within 30 minutes. The detoxification effect of the strain tended to stabilize between 30 and 70 minutes. At 70 minutes, OTA at 50 μg / mL was completely detoxified by the strain. This indicates that *Xanthomonas pseudoxanthomonas* X-22 can detoxify high concentrations of OTA in a very short time, and the strain has a very efficient OTA detoxification ability.

[0073] Example 4.

[0074] Application of Xanthomonas pseudoxanthomonas X-22 in the detoxification of OTA in contaminated corn and oats.

[0075] 1) Grind corn and oats into powder using a grinder, and filter through a 40-mesh sieve. Weigh 2.5g of corn flour and 2.5g of oat flour into 50mL centrifuge tubes, seal with heat-resistant and breathable sealing film, and sterilize in an autoclave at 121℃ for 15min. After sterilization, allow the corn flour and oat flour to reach room temperature and test the initial OTA content. After testing, add OTA standard to achieve a final OTA concentration of 1μg / mL.

[0076] 2) Contaminated corn flour and oat flour were added to sterile water at a material-to-liquid ratio of 1:1 (g / mL). 1.5 mL of *Xanthomonas pseudoepiplo* X-22 bacterial suspension was inoculated, stirred thoroughly, and placed in a 37℃ constant temperature and humidity incubator for 72 hours of fermentation. Contaminated corn flour and oat flour samples without bacterial suspension were used as blank controls. During fermentation, the samples were stirred and turned every 12 hours to ensure complete fermentation. Samples were taken at 12h, 24h, 36h, 48h, 60h, and 72h to determine the OTA detoxification rate. The results are as follows: Figure 10 As shown.

[0077] from Figure 10 It can be seen that *Pseudomonas pseudoxanthomonas* X-22 can significantly detoxify OTA from corn and oats, and the detoxification effect of the strain in oats is significantly higher than that in corn. The OTA detoxification rate increases with time, and 12–48 h is the time range in which *Pseudomonas pseudoxanthomonas* X-22 has the highest OTA detoxification efficiency. The detoxification rate of OTA in corn significantly increased from 26.05% (12 h) to 58.70% (48 h), and the detoxification rate of OTA in oats significantly increased from 57.88% (12 h) to 95.45% (48 h). From 48 to 72 h, the strain showed some improvement in the OTA detoxification rate of both raw materials, but the change was not significant. At 72 h, the detoxification rates of the strain in corn and oats were 61.29% and 97.26%, respectively. The different OTA detoxification rates of Xanthomonas pseudoepiplocinus X-22 in corn and oats may be due to the different nutrient and moisture contents in the different raw materials, which leads to differences in the growth and metabolism of the strain and thus different detoxification effects on OTA.

[0078] Example 5.

[0079] The OTA detoxification active substances of *Xanthomonas pseudoepiploiculata* X-22 are mainly found intracellularly. *Xanthomonas pseudoepiploiculata* X-22 was cultured to OD... 600 =1.0, centrifuge to collect bacterial cells, wash with PBS and resuspend, then sonicate on ice for 30 min (5 s working, 5 s interval). Centrifuge the lysate and filter through a 0.22 μm filter membrane to obtain crude intracellular enzyme solution.

[0080] The crude intracellular enzyme solution was incubated with OTA at a final concentration of 50 μg / mL in a constant temperature shaking incubator at 37℃ and 180 rpm for 60 min. OTA was extracted and analyzed by HPLC, and the changes in HPLC peaks before and after detoxification were compared. OTA was identified by comparing the chromatograms of OTA standards and samples, and the detoxified product was identified by comparing the chromatograms of OTα standards and newly emerging detoxified product peaks.

[0081] The crude intracellular enzyme solution of *Xanthomonas pseudoepiplo* X-22 was co-incubated with OTA at a final concentration of 50 μg / mL in a constant temperature shaking incubator at 37℃ and 180 rpm for 60 min. The changes in HPLC peak chromatograms before and after detoxification were compared. The results are as follows: Figure 11 As shown in the HPLC peak chromatogram of the OTA standard, the elution time of OTA is approximately 11.0 min. Figure 11 As shown in Figure a), the HPLC peak chromatogram of the OTα standard shows that the elution time of OTα is approximately 4.3 min. Figure 11 Figure b in the figure). By comparing the HPLC peak chromatograms before and after OTA detoxification with intracellular crude enzyme solution ( Figure 11 Figure c in the middle and Figure 11As shown in Figure d), the peak of OTA decreased significantly after detoxification, and a new peak appeared at around 4.3 min, which is presumed to be the OTA detoxification product. By comparing the OTα standard and the new peak produced after detoxification, the elution times of the two were consistent. Therefore, it is preliminarily speculated that the crude enzyme solution of *Xanthomonas pseudoepiplo* X-22 detoxified OTA into Otα.

[0082] LC-MS analysis of OTA detoxification products: LC-MS was used to further identify the products of OTA detoxified from Xanthomonas pseudoxanthomonas X-22, confirming the presence of OTα. For example... Figure 12 As shown, OTα ([M+H]+, C11H8ClO5, m / z=257.02) was detected using LC-MS in positive ion mode at a retention time of 5.58 min. Two characteristic fragments confirming the presence of OTα were m / z=257.02 (representing OTα) and m / z=211.02 (representing OTα without a carboxyl group). Currently, the biodegradation pathway of OTA mainly involves hydrolyzing the amide bond between OTA isocoumarin residues and phenylalanine to generate OTα and L-β-phenylalanine. Since L-β-phenylalanine is considered harmless to organisms, and animal experiments have shown that the toxicity of OTα is much lower than that of OTA (its half-life in animals is approximately one-tenth that of OTA), degrading OTA into OTα and L-β-phenylalanine is considered the most reliable method for OTA biodetoxification.

[0083] It should be noted that, unless otherwise specified, the experimental methods used in the examples are conventional methods. Unless otherwise specified, the materials and reagents used in the examples are commercially available.

[0084] It should also be noted that the technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0085] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Parts not described in the specific embodiments are all prior art or common knowledge.

Claims

1. A strain of *Xanthomonas pseudoepiphyllum*, characterized in that, It is deposited at the Guangdong Provincial Center for Microbial Culture Collection, with accession number GDMCC No: 67026.

2. A biological detoxifying agent, the active ingredient of which is *Xanthomonas pseudoxanthomonas* bacterial culture, *Xanthomonas pseudoxanthomonas* bacterial suspension, or *Xanthomonas pseudoxanthomonas* cell contents, wherein the preservation number of *Xanthomonas pseudoxanthomonas* is GDMCC No: 67026.

3. The biological detoxifier according to claim 2, characterized in that, The biological detoxifier is either liquid or solid.

4. The biological detoxifier according to claim 2, characterized in that, The preparation method includes: activating Xanthomonas pseudoepiploicum with preservation number GDMCCNo:67026, multi-stage expansion culture, and collecting the fermentation culture when the bacterial cells are in the stationary phase to obtain a liquid biological detoxifier; Alternatively, activate Xanthomonas pseudoepiploicum with accession number GDMCC No: 67026, expand it through multiple stages, collect the fermentation broth when the cells are in the stationary phase, centrifuge the fermentation culture to collect the cells and break them to obtain the cell contents and prepare a liquid biological detoxifier. Alternatively, activate Xanthomonas pseudoepiploicum with accession number GDMCC No: 67026, expand it through multiple stages, and when the cells are in the stationary phase, collect the fermentation broth, centrifuge the fermentation culture to collect the cells and obtain a solid biological detoxifier; Alternatively, activate *Xanthomonas pseudoepiploicus* with accession number GDMCC No: 67026, expand it through multiple stages, collect the fermentation broth when the cells are in the stationary phase, centrifuge the fermentation culture to collect the cells and break them to obtain the cell contents, and use the cells to prepare a solid biological detoxifier.

5. The application of *Pseudomonas aeruginosa* as described in claim 1 in the degradation of ochratoxin A.

6. The use of the biological detoxifier as described in claim 2, 3 or 4 in the degradation of ochratoxin A.

7. The application of *Xanthomonas pseudoepiplocinus* as described in claim 1 for the detoxification of OTA in contaminated corn and oats.

8. The application of the biological detoxifying agent as described in claim 2, 3 or 4 for the detoxification of OTA in contaminated corn and oats.

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