Achromobacter madepla AM6323 and application thereof in biological detoxification of aflatoxin

Abstract

The invention relates to the technical field of microbial degradation, and in particular relates to achromobacter margaritae AM6232 and an application thereof in biological detoxification of aflatoxin. The achromobacter mardeprae AM6232 is preserved in the China General Microbiological Culture Collection Center (CGMCC), and the preservation number is CGMCC NO.34864. The achromobacter mardelpicae AM6232 and the culture thereof have a good degradation effect on various aflatoxins, especially have a high degradation rate on aflatoxin AFB1, and can be used for removing aflatoxins in agricultural products.

Description

Technical Field

[0001] This invention relates to the field of microbial degradation technology, specifically to a type of Achromobacterium martensii AM6323 with highly efficient aflatoxin degradation capabilities and its applications. Background Technology

[0002] aflatoxin ( Aflatoxins ) is caused by Aspergillus flavus ( Aspergillus flavus ), parasitic aspergillus ( Aspergillus parasiticus Aflatoxins, secondary metabolites produced by fungi such as arsenic, are highly carcinogenic, teratogenic, and mutagenic, and are classified as Group 1 carcinogens by the International Agency for Research on Cancer. They are widely found in agricultural products and foods such as corn, peanuts, rice, edible oils, oilseed cakes, and animal feed, seriously threatening the quality and safety of agricultural products and the health of humans and animals. Currently, more than 20 types of aflatoxins have been identified, the most common being aflatoxin AFB1, aflatoxin AFB2, aflatoxin AFB1, and aflatoxin AFB2. Among them, aflatoxin AFB1 has the highest yield and the strongest biotoxicity. Studies have shown that its median lethal dose (LD50) is only 0.36 mg / kg, making it 10 times more toxic than potassium cyanide and 68 times more toxic than arsenic. Therefore, monitoring and preventing aflatoxin AFB1 contamination is particularly important.

[0003] Currently, methods for degrading AFB1 mainly include physical detoxification, chemical detoxification, and biological detoxification. Physical and chemical detoxification methods have drawbacks such as high cost, potential damage to nutrients, or secondary pollution. Biological degradation, on the other hand, has become a research hotspot in the field of AFB1 detoxification due to its advantages such as safety, high efficiency, environmental friendliness, and high specificity. Biological detoxification mainly refers to methods that utilize organisms or their metabolites to reduce or eliminate fungal toxins. Currently reported microorganisms with AFB1-degrading capabilities mainly include Bacillus (…). Bacillus spp.), lactic acid bacteria ( lactic acid bacteria Streptomyces ( streptomyces spp.), Pseudomonas ( Pseudomonas The degradation efficiency varies depending on the strain and the crop, including spp. and non-toxic Aspergillus species.

[0004] Although biological degradation of AFB1 has many advantages, it still faces challenges in practical applications, including unstable activity, demanding reaction conditions, and limited application scope. Furthermore, there is currently no information regarding *Achromobacterium* (…). Achromobacter Research reports on the degradation of AFB1 by spp. Summary of the Invention

[0005] In view of this, the present invention provides a *Achromobacterium martensii* (… Achromobacter marplatensisAM6323 is a strain that has a high efficiency in degrading aflatoxins, especially AFB1, and its application effect is stable.

[0006] Another object of the present invention is to provide a culture of the above-mentioned Achromobacterium martensii AM6323.

[0007] A third objective of this invention is to provide a method for culturing Achromobacterium martensii AM6323.

[0008] A fourth objective of this invention is to provide the application of the aforementioned Achromobacterium martensii AM6323 in the degradation of aflatoxin.

[0009] The fifth objective of this invention is to provide aflatoxin biological detoxifier containing the aforementioned Achromobacterium martensii AM6323.

[0010] The sixth objective of this invention is to provide a method for removing aflatoxin from agricultural products.

[0011] To achieve the above objectives, the present invention adopts the following technical solution:

[0012] This invention provides a Mar delta achromobacterium ( Achromobacter marplatensis AM6323, with accession number CGMCC NO.34864.

[0013] The present invention also includes a culture of the above-mentioned Achromobacterium martensii AM6323, which is a substance obtained by culturing the above-mentioned Achromobacterium martensii AM6323 in a microbial culture medium.

[0014] In one embodiment, the culture comprises a suspension, intracellular lysis broth, fermentation broth, and / or metabolites of Achromobacter madrapata AM6323.

[0015] As one embodiment, the culture described in this invention is an unsterilized and / or sterilized culture.

[0016] The present invention also provides a method for culturing the above-mentioned Achromobacterium martensii AM6323, wherein the Achromobacterium martensii AM6323 is inoculated into LB liquid medium and cultured with shaking at 25-30°C for 1-120 h, more preferably 4-20 h.

[0017] The present invention also provides the application of the above-mentioned Achromobacterium martensii AM6323 and its culture in the prevention or degradation of aflatoxin.

[0018] The present invention provides an aflatoxin biological detoxifier, wherein the aflatoxin degrading agent comprises the above-mentioned Achromobacterium martensii AM6323 and / or the above-mentioned culture.

[0019] This invention provides a method for removing aflatoxin from agricultural products by mixing the above-mentioned Achromobacter madrapata AM6323 and / or the above-mentioned culture into the agricultural products.

[0020] In one embodiment, the mass ratio of the *Achromobacterium martensii* AM6323 and / or the culture mixed into the agricultural product is 1%-10%.

[0021] Compared with the prior art, the present invention has the following advantages and effects:

[0022] The *Achromobacterium martensii* AM6323 of this invention exhibits good degradation activity against various aflatoxins, especially a high degradation rate against aflatoxin AFB1. The *Achromobacterium martensii* AM6323 of this invention achieved a degradation rate of 84.2% for AFB1 standard after 72 hours and a degradation rate of 77.84% for AFB1 in corn kernels, fully demonstrating the stability of this bacterium in degrading AFB1.

[0023] The bacterial suspension, intracellular lysis broth, and fermentation broth of *Achromobacterium martensii* AM6323 of this invention all have the effect of degrading aflatoxin. Among them, the degradation rate of sterilized fermentation broth reached the highest, reaching 89.80%, indicating that the active ingredient of *Achromobacterium martensii* AM6323 of this invention for degrading AFB1 exists in the sterile fermentation broth.

[0024] The present invention, *Achromobacterium martensii* AM6323, has advantages such as low resistance to drug development and environmental friendliness. Its sterile fermentation broth has high temperature resistance, which is beneficial for product development, production and long-term storage.

[0025] Preservation Instructions

[0026] Achromobacterium martensii ( Achromobacter marplatensis AM6323 was deposited on June 12, 2025, at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC NO.34864; address: No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences. Attached Figure Description

[0027] Figure 1 The effect of strain AM6323 on AFB1 degradation at different time points.

[0028] Figure 2The images show the colony morphology of strain AM6323, with the left side showing the front of the colony and the right side showing Gram staining.

[0029] Figure 3 Phylogenetic tree of strain AM6323 obtained based on 16S rRNA sequence.

[0030] Figure 4 This is a phylogenetic tree of strain AM6323 obtained based on the gyrB gene sequence.

[0031] Figure 5 The growth curve of strain AM6323 is shown.

[0032] Figure 6 The active substances of strain AM6323 were localized, where A: cell suspension (unsterilized); B: cell suspension (sterilized); C: intracellular lysis buffer (unsterilized); D: intracellular lysis buffer (sterilized); E: sterile fermentation broth (unsterilized); F: sterile fermentation broth. Detailed Implementation

[0033] In July 2014, samples were collected from the rhizosphere soil of maize plants in Kangping, Liaoning Province. A strain of *Achromobacterium martensii* was obtained through screening using the plate dilution method. Achromobacter marplatensis AM6323 is a strain that exhibits good degradation activity against various aflatoxins, especially a high degradation rate against aflatoxin AFB1.

[0034] Currently, this *Achromobacterium martensii* has been deposited at the China General Microbiological Culture Collection Center (CGMCC), accession number: CGMCC NO.34864; address: No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences; deposit date: June 12, 2025; classification and naming: Achromobacter marplatensis AM6323.

[0035] The morphological characteristics of Achromobacterium martensii AM6323 on LB solid plates after 24 h are as follows: the colonies are translucent milky yellow, round, 2-3 mm in diameter, with neat edges, smooth and raised surface; Gram staining results are negative, and the bacteria are observed to be short rod-shaped under a microscope.

[0036] Based on homology comparison of the 16S rRNA sequence and gyrB sequence, the strain AM6323 of the present invention was identified as Achromobacter madrapata, belonging to the phylum Proteobacteria, class β-Proteobacteria, order Burkholderia, family Alcaligenesaceae, and genus Achromobacter.

[0037] In this invention, the aforementioned culture of *Achromobacterium martensii* AM6323 refers to the substance obtained by culturing *Achromobacterium martensii* AM6323 in a microbial culture medium, including but not limited to bacterial suspensions, intracellular lysates, fermentation broths, and / or their metabolites of *Achromobacterium martensii* AM6323. The microbial culture medium here refers to a medium capable of promoting the growth and proliferation of *Achromobacterium martensii* AM6323, including but not limited to LB medium, and improved media on LB medium to better promote the growth or metabolism of *Achromobacterium martensii* AM6323. Those skilled in the art can adjust or improve the culture medium and culture conditions according to actual culture circumstances. The culture of this invention can be an unsterilized culture or a sterilized culture. Experiments have shown that the sterilized fermentation broth achieved a maximum degradation rate of 89.8% for aflatoxin AFB1, while the unsterilized fermentation broth achieved a degradation rate close to 80% for aflatoxin AFB1.

[0038] The method for culturing *Achromobacterium martensii* AM6323 according to the present invention involves inoculating *Achromobacterium martensii* AM6323 into LB liquid medium and culturing it with shaking at 25-30°C for 1-120 h. The culture temperature is further preferably 26-29°C, and even more preferably 27-28°C; the culture time is further preferably 4-20 h. During the culture process, 0-4 h is the lag phase, during which the bacterial concentration increases slowly; 4-20 h is the logarithmic growth phase, during which the bacterial cells proliferate rapidly; the strain reaches a stable period at 20 h, and this stable period is relatively long, remaining stable even after 120 h.

[0039] The *Achromobacterium martensii* AM6323 and its culture of the present invention possess the function of degrading various aflatoxins and can serve as the sole or partial active ingredient of an aflatoxin detoxifier. Preferably, the *Achromobacterium martensii* AM6323 and its culture of the present invention exhibit general degradation efficiency against four aflatoxins: AFB1, AFB2, AFG1, and AFG2, with particularly better degradation effect on aflatoxin AFB1. When the fermentation broth of this strain is co-cultured with an AFB1 standard, the degradation rate can reach up to 87.6%.

[0040] To pinpoint the active components of *Achromobacterium martensii* AM6323 against AFB1 and determine its detoxification mechanism, this invention investigated the degradation activity of strain AM6323. Results showed that the active components of AM6323 for AFB1 degradation were present in the sterile fermentation broth, and the degradation activity of the sterile fermentation broth was significantly higher than that of intracellular lysate and cell suspension. The highest degradation rate (89.80%) was observed in the sterile fermentation broth after sterilization, while the degradation rate of the non-sterilized broth was close to 80%. Compared to the non-sterilized broth, heating the sterile fermentation broth to 121°C increased the AFB1 removal rate by 13.15%. Therefore, it was determined that strain AM6323 removes AFB1 through both adsorption and degradation.

[0041] In another aspect, this invention provides an aflatoxin biological detoxifier containing *Achromobacterium martensii* AM6323 and / or its culture as described in this invention. The biological detoxifier of this invention can be produced according to methods well known to those skilled in the art. The formulation type of the biological detoxifier can be a solution, dispersant, suspension, granule, etc.

[0042] In some embodiments, the biological detoxifying agent of the present invention also includes a different microbial strain from the Achromobacterium martensii AM6323 of the present invention. The combined use of different microorganisms expands the spectrum of microbial agents, improves the removal effect of aflatoxin, and delays the development of drug resistance.

[0043] In some embodiments, the *Achromobacterium martensii* AM6323 or its culture of the present invention can be prepared as a biological detoxifier by freeze-drying or dissolving in a suitable solvent. Freeze-drying is performed using conventional methods in the art. The solvent may be water, a microbial culture medium, or the like.

[0044] Aflatoxin is commonly found in agricultural products during storage and transportation due to environmental factors such as high temperature and humidity, and poor ventilation, leading to the metabolism of fungi like Aspergillus flavus. The agricultural products of this invention include, but are not limited to, grains, nuts, and oilseeds, such as corn, peanuts, rice, edible oil, oilseed meal, and animal feed. Given that *Achromobacterium martensii* AM6323 or its cultures exhibit high aflatoxin removal efficiency, it can be used to remove aflatoxin from agricultural products. This invention proposes a method for removing aflatoxin from agricultural products, involving mixing *Achromobacterium martensii* AM6323 and / or its cultures with agricultural products to degrade aflatoxin. As one embodiment, the mass ratio of *Achromobacterium martensii* AM6323 and / or its cultures mixed into the agricultural products is 1%-10%, more preferably 3%-5%. In some embodiments, the present invention adds the fermentation broth of strain AM6232 at a dosage of 3% to corn kernels contaminated with Aspergillus flavus, mixes it evenly, and after 3 days, the degradation rate of aflatoxin AFB1 in corn kernels is 77.84%, showing potential application value.

[0045] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited to the following embodiments and does not constitute any limitation on the scope of protection of the present invention.

[0046] Unless otherwise specified, the experimental methods used in the examples are conventional methods, and the materials and reagents used are commercially available.

[0047] Example 1

[0048] Screening of degrading strains

[0049] AFB1 standard was prepared using acetonitrile to a concentration of 1 μg / mL and stored at 4℃. The test strain was activated and inoculated into a 250 mL Erlenmeyer flask containing 150 mL of LB liquid medium. The flask was incubated overnight at 28℃ and 180 r / min with shaking. The cell concentration of the test strain was adjusted to the same level (OD600≈0.8). 900 μL of fermentation broth was taken, and 100 μL of the 1 μg / mL AFB1 standard was added to bring the final AFB1 concentration in the fermentation broth to 0.1 μg / mL. A sterile LB medium containing 0.1 μg / mL AFB1 was used as a blank control. After incubation at 28℃ for 72 h, the mixture was centrifuged at 12000 r / min for 5 min. The supernatant was collected to determine the AFB1 content, calculate the degradation rate, and screen strains with high toxin degradation rates.

[0050] The AFB1 content was determined by high performance liquid chromatography (HPLC), and the specific method is as follows:

[0051] Add 300 μL of the sample to 900 μL of acetonitrile, mix well, and freeze at -20℃ for 10 min. Then centrifuge at 12000 r / min for 15 min at 4℃ and collect the supernatant. Dilute the supernatant 100 times with acetonitrile, and add 1.5 mL of the diluted solution to the purification agent (25 mg PSA, 10 mg C). 18 Centrifuge at 12000 r / min for 5 min; filter the supernatant through a 0.22 μm organic phase filter membrane into a liquid chromatography vial, and determine the AFB1 content by high performance liquid chromatography (HPLC). Chromatographic column: WATER ACQUITY UPLC BEH C18 column (50×2.1 mm, 1.7 μm, Waters Corporation, USA); column temperature: 40℃; injection volume: 0.3 μL; flow rate: 0.2 mL / min; mobile phase (A): water; mobile phase (B): methanol. Gradient elution program: 0 ~ 0.5 min, 60% A; 0.5 ~ 4.5 min, 60% A; 4.5 ~ 5.0 min, 2% A; 5.0 ~ 6.0 min, 2% A; 6.0 ~ 6.5 min, 60% A; 6.5 ~ 8.0 min, 60% A; analysis time: 8.0 min.

[0052] AFB1 degradation rate = (AFB1 concentration in the control group - AFB1 concentration in the experimental group) / AFB1 concentration in the control group × 100%

[0053] The high degradation rate strains obtained from the initial screening were adjusted to OD600≈0.8 using the method described above. Nine mL of the strain's fermentation broth was mixed with 1 mL of AFB1 at a concentration of 1 μg / mL and cultured. Toxin concentrations were measured at 12 h, 24 h, 36 h, 48 h, 60 h, 72 h, 84 h, 96 h, 108 h, and 120 h. A detoxification curve was plotted with culture time on the x-axis and degradation rate on the y-axis to analyze the changes in toxin degradation rate over different time periods and to screen for dominant strains with high degradation rates over short periods.

[0054] Results: The degradation rate of strain AM6323 reached 56% after 48 h of culture, and the degradation rate tended to stabilize after 60 h, reaching a maximum of 87.6%, which was significantly higher than that of other strains (P<0.05). This indicates that it has the ability to efficiently degrade AFB1 in a short time. Therefore, strain AM6323 was selected as the target strain for subsequent research.

[0055] Example 2

[0056] Morphological identification of strains

[0057] The target strain was streaked on solid LB agar plates and incubated upside down at 28°C for 24 h. The colony color, size, shape, edge, surface, raised shape, and transparency were observed. The strain was Gram stained and the bacterial morphology, color, and characteristics were observed under a microscope.

[0058] See results Figure 2 The colonies of strain AM6323 on LB agar plates after 24 h were translucent milky yellow, round, 2-3 mm in diameter, with neat edges and a smooth, raised surface; Gram staining was negative, and the bacteria were observed to be short rod-shaped under a microscope.

[0059] Example 3

[0060] Molecular identification of strains

[0061] DNA from the target strain was obtained by boiling in water. The 16S rDNA and gyrB gene fragments were amplified using primers 27F / 1492R and gyrB-F / gyrB-R, respectively. The universal primers for the 16S rDNA sequence were: 27F: 5'-AGAGTTTGATCCTGGCTCAG-3'; 1492R: 5'-CTACGGCTACCTTGTTACG A-3'. The primers for the gyrB gene were: gyrB-F: 5'-TTGRCGGHRGYGGHTATAAAGT-3'; gyrB-R: 5'-TCCDCCSTCAGARTCWCCCTC-3'. The PCR reaction system (25 μL) consisted of 12.5 μL of 2×Tran mix and 10 μmol·L⁻¹. -1 0.5 μL each of upstream and downstream primers, 1.5 μL of DNA, and ddH2O were added to a final volume of 25 μL. PCR reaction conditions: 95℃ pre-denaturation for 5 min; 95℃ denaturation for 30 s, 55℃ annealing for 30 s, 72℃ extension for 90 s, for a total of 35 cycles; followed by a final extension at 72℃ for 7 min. The amplified products were sequenced by Sangon Biotech (Shanghai) Co., Ltd., and the sequencing results were compared for homology in GenBank. Simultaneously, known sequences with high homology were selected, and a phylogenetic tree was constructed using MEGA 5.2 software to determine the taxonomic position of the pathogen.

[0062] The 16S rRNA and gyrB sequences of strain AM6323 were compared for homology in GenBank. The results showed that strain AM6323 was most closely related to the 16S rRNA sequence of *Achromobacter madrapata* (accession number MW132892.1), with a homology similarity of 99.72%; and most closely related to the gyrB gene sequence of *Achromobacter madrapata* (accession number HG454857.1), with a homology similarity of 99.31%. A phylogenetic tree was constructed using MEGA 5.2 software, and the results showed that strain AM6323 clustered with *Achromobacter madrapata*, indicating that strain AM6323 belongs to *Achromobacter madrapata*.

[0063] Based on morphological characteristics and molecular biological identification results, strain AM6323 was identified as Achromobacter madrapata, belonging to the phylum Proteobacteria, class β-Proteobacteria, order Burkholderia, family Alcaligenesaceae, and genus Achromobacter. This strain was named AM6323.

[0064] Example 4

[0065] Determination of growth curves of degrading strains

[0066] The activated strains on LB plates were inoculated into LB liquid medium and cultured at 28°C with shaking at 180 r / min until OD. 600 ≈0.5; 1 mL of bacterial culture was inoculated into a 150 mL Erlenmeyer flask containing 50 mL of LB liquid medium, and cultured at 28℃ with shaking at 180 r / min, with 3 replicates. Samples were taken every 4 h, and the absorbance at 600 nm was measured; the absorbance was plotted on the x-axis as incubation time and OD. 600 The value is used as the ordinate to plot the growth curve of the strain.

[0067] The growth curve of strain AM6323 shows ( Figure 5 The 0-4 h period is the delay phase, during which the bacterial cell concentration increases slowly; the 4-20 h period is the logarithmic growth phase, during which the OD... 600 The OD value rises rapidly, indicating massive bacterial proliferation; the strain reaches a stable growth phase after 20 hours, at which point the OD value... 600 The value was 1.4. This strain has a long stable period, remaining stable for 120 hours.

[0068] Example 5

[0069] Localization analysis of active components that degrade toxins

[0070] The degrading strain was transferred to a 250 mL Erlenmeyer flask containing 150 mL of LB liquid medium and cultured at 28 °C and 180 r / min for 12 h to obtain the seed culture. The seed culture was then transferred to LB liquid medium at a 10% inoculum and cultured for another 16 h with shaking to obtain the bacterial culture for later use.

[0071] Preparation and treatment of bacterial suspension: A portion of the bacterial suspension was centrifuged at 8000 r / min for 10 min at 4℃. The bacterial cells were resuspended in sterile PBS buffer (pH 7.0), centrifuged again for 8 min, and the supernatant was discarded. This process was repeated three times. The bacterial cells were then reconstituted in PBS buffer to ensure the cell concentration was consistent with that before centrifugation, thus obtaining the bacterial suspension. A portion of the bacterial suspension was sterilized at 121℃ for 20 min. 900 μL of the bacterial suspension and the inactivated bacterial suspension were respectively added to 100 μL of AFB1 standard with a mass concentration of 1 μg / mL. The mixture was incubated at 28℃ with shaking at 180 r / min, with sterile PBS buffer containing 0.1 μg / mL AFB1 as a blank control.

[0072] Preparation and processing of intracellular substances: The bacterial suspension was ground and crushed, centrifuged at 10,000 r / min for 10 min at 4℃, and the supernatant was filtered through a 0.22 μm filter; a portion of the filtrate was sterilized at 121℃ for 20 min. 900 μL of cell lysis buffer and inactivated lysis buffer were added to 100 μL of AFB1 standard with a mass concentration of 1 μg / mL, respectively, with sterile PBS buffer containing 0.1 μg / mL AFB1 as a blank control.

[0073] Preparation and treatment of sterile fermentation broth: The fermentation broth was centrifuged at 10,000 r / min for 10 min at 4℃, and the supernatant was filtered through a 0.22 μm filter; a portion of the filtrate was sterilized at 121℃ for 20 min. 900 μL of fermentation supernatant and inactivated supernatant were taken separately, and 100 μL of AFB1 standard with a mass concentration of 1 μg / mL was added. The mixture was incubated at 28℃ with shaking at 180 r / min, using sterile LB medium containing 0.1 μg / mL AFB1 as a blank control.

[0074] After 3 days of each treatment reaction, the AFB1 concentration was determined and the degradation rate was calculated according to the method in Example 1.

[0075] The results of the active component localization assay showed that each treatment exhibited significantly different AFB1 removal activities. The degradation activity of the sterile fermentation broth was significantly higher than that of the intracellular lysate and cell suspension. In the sterile fermentation broth, the degradation rate of the sterilized treatment reached the highest at 89.80%, while the degradation rate of the non-sterilized treatment was close to 80%. In contrast, the highest degradation rate of the intracellular lysate (unsterilized / sterilized) was 21.46%, and the highest degradation rate of the cell suspension (unsterilized / sterilized) was 11.65%.

[0076] Example 6

[0077] Application of degrading bacteria in maize

[0078] The activated Aspergillus flavus strain was cultured on PDA plates for 5 days until the colonies were fully grown. After spores were washed away with sterile water and filtered through two layers of sterile gauze, a 1×10⁻⁶ sample was prepared. 6 Prepare a spore suspension of 1 spores / mL for later use. Wash corn kernels and soak them in water for 12 hours. Place the soaked corn kernels in heat-resistant bags and sterilize at 121℃ for 45 minutes. After cooling to room temperature, inoculate at a concentration of 1×10⁻⁶ at a 1% inoculation rate. 6 A solution of Aspergillus flavus with 1 spore / mL was mixed and incubated at 25°C for 48 h. Then, sterile fermentation broth of the degrading strain was added at a 3% inoculum, with sterile water used as a blank control. The AFB1 concentration in corn kernels was measured after 3 days of reaction, and the degradation rate was calculated.

[0079] Weigh 2.00 g (accurate to 0.0001 g) of the homogenized corn sample and place it in a 50 mL plastic centrifuge tube. Accurately transfer 10 mL of acetonitrile, shake thoroughly for 3 min, sonicate for 30 min, add 1.00 g of anhydrous magnesium sulfate and sodium chloride, shake thoroughly for 3 min, centrifuge at 8000 r / min for 5 min, and transfer 1.5 mL of the supernatant to a 2 mL matrix dispersion solid-phase extraction purification tube (containing 25 mg PSA and 25 mg C). 18 The solution was purified by 10 mg GCB and 10 mg ZrO2, vortexed for 5 min, and then placed in a refrigerated centrifuge. It was centrifuged at 10000 r / min for 5 min at 4 °C. 1 mL of the supernatant was accurately transferred and filtered through a 0.22 μm microporous organic filter membrane. The AFB1 concentration was then determined by high performance liquid chromatography according to Example 1.

[0080] The results are shown in Table 1. The supernatant from the fermentation of strain AM6232 was used to test the detoxification of aflatoxin in corn kernels. After 72 hours of mixed culture, the degradation rate of AFB1 in the fermentation broth reached 77.84%. This indicates that this strain demonstrates potential application value in the field of mycotoxin contamination control in grains.

[0081] Table 1. Degradation effect of AM6232 on AFB1 in corn kernels

[0082] deal with Repeat 1 Repeat 2 Repeat 3 average AM6232 81.40% 79.39% 72.73% 77.84%

[0083] Example 8

[0084] Degradation effect on other aflatoxins

[0085] Preparation of aflatoxin mixed standard curve: Take 100 μL each of 1 μg / mL AFB2, AFG1, and AFG2 standards, add 700 μL of acetonitrile to obtain a 100 μg / L mixed standard solution; then dilute it to a series of concentrations of 1, 2.5, 5, 10, and 25 μg / L. Mix the fermentation broth of the dominant strain with the series of mixed standard solutions, and analyze the degradation ability of the strain for various aflatoxins.

[0086] The results are shown in Table 2: The degradation test results of strain AM6323 on AFG1, AFG2 and AFB2 showed that the degradation rate of AFG1 was 55.4%, the degradation rate of AFG2 was 35.7% and the degradation rate of AFB2 reached 74.9%, indicating that this strain can not only efficiently degrade AFB1, but also has a certain broad-spectrum degradation ability for other aflatoxins.

[0087] Table 2. Degradation effects of AM6232 on other aflatoxins

[0088] deal with Repeat 1 Repeat 2 Repeat 3 average <![CDATA[AFB2]]> 74.92 77.12 72.76 74.94±1.26a <![CDATA[AFG1]]> 56.61 52.11 57.35 55.35±1.64b <![CDATA[AFG2]]> 30.17 41.29 35.61 35.69±3.21c

[0089] The above embodiments are the best implementations of the present invention, but the implementations of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A type of *Achromobacterium martensii* ( Achromobacter marplatensis AM6323 is characterized by, The preservation number of the Achromobacter marplatensis is CGMCC NO. 34864.

2. The culture of Madurella mycetomi AM6323 according to claim 1, characterized in that, The culture is a substance obtained by culturing the Achromobacter marplatensis AM6323 of claim 1 in a microbial culture medium.

3. The culture of claim 2, wherein, The culture includes a bacterial suspension, an intracellular lysate, a fermentation broth and / or a metabolite of the Achromobacter marplatensis AM6323.

4. The culture of claim 3, wherein, The culture is a non-sterilized and / or sterilized culture.

5. The culture method of the Madurella mycetomi AM6323 according to claim 1, characterized in that, The Achromobacter marplatensis AM6323 is inoculated into an LB liquid culture medium and cultured at 25-30°C for 1-120 h with shaking.

6. The culturing method according to claim 1, wherein The time of the shaking culture is 4-20 h.

7. Use of the Achromobacter marplatensis AM6323 of claim 1 and its culture in preventing or degrading aflatoxins.

8. An aflatoxin biodecontaminating agent, characterized by, The aflatoxin degrading agent includes the Achromobacter marplatensis AM6323 of claim 1 and / or the culture of any one of claims 2-4.

9. A method for removing aflatoxins from agricultural products, characterized by, The Achromobacter marplatensis AM6323 of claim 1 and / or the culture of any one of claims 2-4 is mixed into agricultural products.

10. The method of claim 9, wherein, The mass ratio of the Achromobacter marplatensis AM6323 of claim 1 and / or the culture of any one of claims 2-4 mixed into the agricultural products is 1%-10%.

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