Ochrobactrum bacteria and fungicide, application and method thereof
The application of the QY4 strain of Bacillus cereus has solved the problem of the scarcity of functional bacterial strains for PET plastic degradation, and has achieved effective biodegradation of PET plastic, which has dual value of ecological restoration and public health.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-09
- Publication Date
- 2026-03-13
AI Technical Summary
Currently, there are very few microbial resources that can degrade PET plastics, and there is a lack of effective treatment methods, which leads to serious environmental pollution.
A bacterial agent containing *Alanobacterium*, particularly *Alanobacterium* strain QY4, is provided as an active ingredient. This agent utilizes the bacterial agent's ability to degrade PET plastic by growing and degrading PET as the sole carbon source.
It achieves effective degradation of PET plastic, breaking ester bonds to generate carboxylic acids and alcohols, reducing molecular weight, destroying crystal structure, and making the degradation process green and environmentally friendly, reducing the burden on the ecosystem.
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Figure CN121653007A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of microbial technology, and in particular to a bacterium of the genus *Aureobacterium*, its inoculum, application, and method. Background Technology
[0002] Plastics are ubiquitous in daily life, bringing convenience while simultaneously placing significant pressure on the environment due to the large amounts of plastic waste. Polyethylene terephthalate (PET) is a petroleum-based thermoplastic polymer. Its durability, high transparency, and lightweight properties have made it one of the most widely used plastics in the world. However, due to its complex structure and slow degradation, PET can persist in nature for extended periods, causing severe pollution to the global ecosystem and threatening human health.
[0003] However, how to degrade PET plastic has become one of the global challenges. Compared with physical and chemical methods, such as acid hydrolysis, alkali hydrolysis, alcohol hydrolysis, and pyrolysis, these methods often have problems such as harsh degradation conditions and high costs. Microbial degradation of PET plastic is one of the most environmentally friendly methods currently available. Although PET plastic can be degraded by microorganisms, very few functional bacterial strains for PET plastic degradation have been discovered so far. There is an urgent need to increase the discovery of relevant functional strains and establish new microbial treatment methods for PET. Summary of the Invention
[0004] In view of the current problems of limited resources of functional bacteria for PET degradation and lack of treatment methods, the purpose of this application is to provide a strain of Aristolochic acid bacteria, a bacterial agent containing Aristolochic acid bacteria, the application of Aristolochic acid bacteria and a bacterial agent containing Aristolochic acid bacteria in the degradation of plastics, and a method for the degradation of polyethylene terephthalate, so as to provide bacterial resources and technical means to solve the problem of PET plastic pollution.
[0005] In a first aspect, this application provides a strain of *Ailuropoda*, wherein the strain of *Ailuropoda* is *Ailuropoda* QY4 (… Ochrobactrum The strain (spe. QY4) has the accession number CCTCC NO: M 2026052.
[0006] In a second aspect, this application provides a microbial agent comprising the *Alanium* bacteria described in the first aspect above.
[0007] Optionally, the above-mentioned bacterial agent contains the *Alanium* bacteria described in the first aspect as an active ingredient.
[0008] In a third aspect, this application provides the use of the *Alanobacterium* bacteria described in the first aspect or the bacterial agent described in any of the second aspects above in the degradation of plastics.
[0009] Optionally, the degradation is carried out by growing plastic as the sole carbon source, gradually degrading the plastic.
[0010] Optionally, the plastic exists in the form of granules, films, or powders.
[0011] Optionally, the plastic is polyethylene terephthalate plastic.
[0012] Optionally, the *Aureobacter* bacteria can degrade polyethylene terephthalate in various aquatic environments.
[0013] Plate culture revealed that the *Ailuropoda* strain (i.e., *Ailuropoda* strain QY4) exhibited rapid proliferation and good growth when cultured with polyethylene terephthalate as the sole carbon source, and was able to tolerate 1... After treatment with *Acanthocephalosporin* strain QY4, the infrared spectrum difference peaks of 20,000 mg / L polyethylene terephthalate (PET) plastic indicate that the ester bonds in PET were broken, generating carboxylic acids and alcohols. Differential scanning calorimetry (DSC) shows that the strain reduced the molecular weight and destroyed the crystal structure of PET plastic. The products detected by pyrolysis chromatography-mass spectrometry support the release of ethylene glycol and other substances from the hydrolysis of PET under the action of the strain. Together, these findings demonstrate that *Acanthocephalosporin* strain QY4 utilizes PET plastic as a carbon source and has plastic degradation capabilities.
[0014] In a fourth aspect, this application provides a method for degrading polyethylene terephthalate (PET). The method involves co-culturing PET with *Alanium* bacteria as described in the first aspect or the bacterial agent described in any one of the second aspects, allowing a strain of *Alanium*—*Alanium* strain QY4—to grow using the plastic to be degraded as the sole carbon source, thus gradually degrading the plastic. The plastic to be degraded is preferably PET plastic. Obtaining this strain opens up a new avenue for controlling PET pollution under different environments, possessing both ecological restoration and public health value.
[0015] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the content of the description, or may be understood by practicing the application. Further advantages of this application may be realized and obtained through the embodiments described in the description and drawings. Attached Figure Description
[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 This is a growth diagram of a strain of *Aureobacterium* QY4 on a purification medium with PET plastic as the sole carbon source, as provided in the embodiments of this application. Figure 2 This is a growth diagram of a strain of *Aureobacterium* QY4 on degradation culture media of different concentrations of microplastic powder, provided in the embodiments of this application; Figure 3 This is an infrared spectrum of a strain of *Aureobacterium* QY4 before and after degradation of PET plastic, provided in an embodiment of this application. Figure 4 This is a differential scanning calorimetry spectrum of the *Acanthocephala* strain QY4 before and after degradation of PET plastic, provided in an embodiment of this application.
[0018] Figure 5 This is a pyrolysis chromatogram of the product obtained by the QY4 strain of the genus *Aureobacterium* after degrading PET plastic, as provided in the embodiments of this application. Detailed Implementation
[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0020] This application discloses a plastic-degrading bacterium that can grow and metabolically degrade polyethylene terephthalate (PET) plastic using PET as the sole carbon source. It has been identified as *Acanthocephala* genus QY4 by 16S rRNA sequencing. Ochrobactrum The strain (spe. QY4) will be described in detail below.
[0021] In a first aspect, this application proposes a bacterium of the genus *Ailuropoda*, the strain of which is named *Ailuropoda* QY4 (…). Ochrobactrum The strain (sp. QY4) was deposited on January 8, 2026 at the China Center for Type Culture Collection, located at No. 299 Bayi Road, Wuchang District, Wuhan City, Hubei Province, with accession number CCTCC NO: M 2026052.
[0022] The above-mentioned *Alanium* strain QY4 and at least one of its cellular components, metabolites, metabolite derivatives, and secretions are all within the scope of protection of this application. It is understood that the cellular components include at least one of cells, the culture medium containing the cells, and various chemical components constituting the cells; the metabolites include at least one of intermediate and final metabolites in metabolism; and the secretions include at least one of nucleic acids, enzymes, antibodies, exosomes, and hormones.
[0023] In an optional embodiment, the 16S rDNA gene sequence of the *Aureobacterium* strain QY4, after identification, is shown in SEQ ID NO.1. For detailed sequence information, please refer to the sequence listing.
[0024] In a second aspect, this application provides a microbial agent containing the *Alanium* bacteria described in the first aspect as an active ingredient.
[0025] In this application, the strain of *Ailuropoda* is *Ailuropoda* strain QY4. The bacterial agent contains *Ailuropoda* bacteria as the active ingredient, specifically *Ailuropoda* strain QY4. There is no particular limitation on the concentration of *Ailuropoda* strain QY4 in the bacterial agent; it can be selected according to specific circumstances. For example, bacterial agents containing different concentrations of *Ailuropoda* strain QY4 can be prepared to adapt to various degradation environments. For environments with high degradation requirements, a bacterial agent containing a higher concentration of *Ailuropoda* strain QY4 is selected; for environments with low degradation requirements, a bacterial agent containing a lower concentration of *Ailuropoda* strain QY4 is selected.
[0026] In this application, the microbial agent preferably contains at least one of the following: live cells, dead cells, and fermentation products of the *Ailuropoda* genus QY4 strain, more preferably live cells, to further improve degradation efficiency. In this application, the term "fermentation product" refers to the metabolites (including intracellular and / or extracellular metabolites) produced by the *Ailuropoda* genus QY4 strain during fermentation or culture.
[0027] In this application, there are no particular limitations on the dosage form of the bacterial agent. It can be prepared into different dosage forms according to different intended uses, and corresponding excipients and other components can be added. For example, the bacterial agent can be a liquid bacterial agent (e.g., a bacterial solution of *Alanium spp.* QY4) and / or a solid bacterial agent (e.g., a powder prepared by drying *Alanium spp.* QY4 or a high-purity formulation prepared through separation and purification). The choice of which excipient to add to which dosage form of bacterial agent is well known to those skilled in the art and will not be elaborated upon here.
[0028] In a third aspect, this application provides the application of the *Alanobacterium* bacteria described in the first aspect or the bacterial agent described in any one of the second aspects in the degradation of plastics, wherein the strain of *Alanobacterium* is *Alanobacterium* strain QY4.
[0029] In a preferred embodiment, the degradation is carried out by growing plastic using plastic as the sole carbon source, gradually degrading the plastic. In the above applications, the plastic can exist in any single or mixed form among particles, films, or films. For example, the above-mentioned strains can be used simultaneously to degrade plastics in both particle and film forms, or simultaneously to degrade plastics in both film and powder forms, or simultaneously to degrade plastics in both particle and powder forms.
[0030] More preferably, the plastic is in the form of microplastic powder. The plastic may be polyethylene terephthalate (PET) plastic.
[0031] In a preferred embodiment, when the plastic is polyethylene terephthalate (PET), the *Alanium* bacteria can degrade PET in various aquatic environments; that is, *Alanium* strain QY4 can degrade PET in various aquatic environments. These aquatic environments may include rivers, oceans, lakes, sewage, and other similar environments.
[0032] This application, through plate culture and scanning electron microscopy, observed that the *Ailuropoda* strain QY4 could rapidly proliferate and grow well when cultured with polyethylene terephthalate as the sole carbon source, and could tolerate 1... After treatment with *Acanthocephalosporin* strain QY4, the difference peaks in the infrared spectrum of 20,000 mg / L polyethylene terephthalate (PET) plastic indicated that the ester bonds in PET were broken, generating carboxylic acids and alcohols. Differential scanning calorimetry (DSC) showed that the strain reduced the molecular weight and disrupted the crystal structure of the PET plastic. The products detected by pyrolysis chromatography-mass spectrometry supported the release of ethylene glycol and other substances from the hydrolysis of PET under the action of the strain, indicating that this strain has the ability to degrade PET plastic. Therefore, using *Acanthocephalosporin* strain QY4 for the biodegradation of PET plastic products is a good method for treating them, and this method is environmentally friendly, further reducing the burden on the ecosystem and representing a sustainable degradation approach.
[0033] In this embodiment, the *Acanthocephala* strain QY4 can grow using polyethylene terephthalate (PET) as its sole carbon source. The process of degrading PET-containing plastics using the *Acanthocephala* strain QY4 primarily utilizes the growth of the strain to both utilize and consume the PET in the plastic, thereby achieving degradation. The *Acanthocephala* strain QY4 provided in this application can utilize plastics, especially PET plastics, as a carbon source and has the function of degrading plastics.
[0034] In a fourth aspect, this application provides a method for degrading polyethylene terephthalate, wherein the *Alanium spp.* QY4 strain described in the first aspect or the bacterial agent described in any one of the second aspects is added to the plastic to be degraded, so that the *Alanium spp.* QY4 strain grows using the plastic to be degraded as the sole carbon source, and the plastic to be degraded is gradually degraded, wherein the plastic to be degraded can be polyethylene terephthalate plastic.
[0035] In one optional embodiment, the polyethylene terephthalate plastic can be polyethylene terephthalate plastic particles, films, or powders. In another optional embodiment, the polyethylene terephthalate plastic is a microplastic powder.
[0036] In one optional embodiment, the polyethylene terephthalate (PET) plastic is degraded by *Alanobacterium* bacteria in various environments; specifically, *Alanobacterium* strain QY4 can degrade PET plastic in various environments, including aquatic environments (such as rivers, lakes, and sewage) or soil environments. In one embodiment, the *Alanobacterium* strain QY4 is brought into contact with the PET plastic, and the plastic is multiplied and degraded in a culture medium.
[0037] In some embodiments, the aged plastic is in the form of micro / nano particles. In some embodiments, the aged plastic is prepared into a plastic stock solution of a certain concentration and added to the liquid plastic-degrading bacteria enrichment culture medium and solid plastic-degrading bacteria purification culture medium described in this application for screening and purification of plastic-degrading bacteria. The concentration of the plastic stock solution can be adjusted according to the type of strain to be isolated or the type of plastic. In one embodiment of this application, the concentration of the plastic stock solution is 1000 mg / L.
[0038] The raw materials used in the various culture media used in this application, such as KH₂PO₄, K₂HPO₄·3H₂O, MgSO₄, NaCl, CaCl₂, Na₂SeO₃·5H₂O, Na₂WO₄·2H₂O, EDTA, FeSO₄·7H₂O, ZnSO₄·7H₂O, MnCl₂·4H₂O, H₃BO₃, CoCl₂·6H₂O, CuCl₂·2H₂O, NiCl₂·6H₂O, and NaMoO₄·2H₂O, are all of analytical grade and commercially available. The instruments used for culturing and enriching bacteria, such as autoclaves, laminar flow hoods, shakers, and incubators, are all conventional instruments.
[0039] Experimental methods in the following embodiments without specific conditions are generally determined according to national standards. Experimental materials in the following embodiments without specified sources are all commercially available raw materials. The equipment used in each step of the following embodiments is conventional equipment. If there is no corresponding national standard, then generally accepted international standards, conventional conditions, or conditions recommended by the manufacturer are followed. Unless otherwise defined or stated, all technical and scientific terms used in this application have the same meaning as those skilled in the art. Furthermore, any methods and materials similar or equivalent to those described herein may be applied to the methods of this application.
[0040] Example 1: Isolation, purification and identification of bacteria of the genus *Ailuropoda* In this embodiment, a well plate plastic enrichment method was used to isolate bacteria capable of degrading polyethylene terephthalate from plastic-contaminated samples. The specific operation process is as follows: First, the contaminated sample was collected and pretreated. This step aims to activate the microbial community in the sample under mild conditions. In this embodiment, the contaminated sample was a 10 g soil sample contaminated with plastic from a landfill in Inner Mongolia. The sample was placed in an Erlenmeyer flask containing 100 mL of mineral water. It was then placed in a shaker at 30 °C and 180 rpm / min and cultured for 24 hours to prepare a bacterial suspension.
[0041] Subsequently, bacterial enrichment and activation were performed, a step aimed at screening for bacteria with potential degradation capabilities using a low-nutrient medium. 100 μL of the sample bacterial suspension and 800 μL of low-nutrient plastic-degrading bacterial enrichment medium (BG11 medium) were added to each well of a 48-well plate and incubated for 24 h at 30 °C and 180 rpm / min to further activate the bacteria.
[0042] Next, the degradation bacteria were domesticated and screened. This step aimed to domesticate the bacteria by adding PET stock solution and screen out degradation bacteria that could utilize PET as the sole carbon source. 100 μL of aged polyethylene terephthalate stock solution (concentration of 1000 mg / L) was added to each well, and the bacteria were then cultured at 30 ℃ and 80 rpm / min for 48 hours to further domesticate the degradation bacteria.
[0043] The aging treatment of polyethylene terephthalate mother liquor was obtained by the following operation: polyethylene terephthalate micro-nano plastics were added to 100 mL of water to prepare a plastic mother liquor of 10 g / L; the plastic mother liquor was placed in a magnetic stirrer and continuously stirred to simulate environmental aging under LED lamps (395 nm wavelength) irradiated with simulated natural ultraviolet light, and incubated at room temperature of 25 °C for 7 days.
[0044] Finally, the degrading bacteria were purified and identified. Polyethylene terephthalate (PET) stock solution was added to the purification medium for the plastic-degrading bacteria. A carbon-nitrogen-free control group without PET extract was also set up. The degrading bacteria acclimatized in the previous step were inoculated onto solid purification medium and cultured at 30 °C for 7 to 20 days. The growth of bacterial colonies was observed and recorded. By comparing the colony growth on media with and without PET, bacteria that grew only on media with PET as the sole carbon source were screened. These bacteria were considered to have the potential to degrade PET. Single colonies with plastic-degrading potential were selected and purified multiple times to finally obtain pure PET-degrading bacteria.
[0045] In the preparation of BG11 and purification culture medium, the culture medium powder is thoroughly mixed and dissolved in ultrapure water. After high temperature and high pressure sterilization, BG11 culture medium can be used directly after cooling. Purification culture medium needs to be cooled to about 60 ℃ and plastic stock solution is added and mixed. It is then poured into the wells of a microplate and cooled to solidify for later use.
[0046] The purification culture medium consisted of: 1 g KH2PO4, 3 g K2HPO4·3H2O, 0.2 g MgSO4, 1 g NaCl, 0.01 g CaCl2, 0.006 g Na2SeO3·5H2O, 0.008 g Na2WO4·2H2O, 0.0005 g EDTA, 0.0002 g FeSO4·7H2O, 0.00001 g ZnSO4·7H2O, 0.000003 g MnCl2·4H2O, 0.00003 g H3BO3, 0.00002 g CoCl2·6H2O, 0.000001 g CuCl2·2H2O, 0.000002 g NiCl2·6H2O, 0.000003 g NaMoO4·2H2O, 15 g agar, and 1 L ultrapure water.
[0047] The purified bacteria for degrading polyethylene terephthalate (PET) were identified by sequencing using 16S rDNA (the 16S rDNA sequence is shown in SEQ ID NO:1, and detailed sequences can be found in the sequence listing). The final purified PET-degrading bacteria were identified as *Aureobacterium* spp. Ochrobactrum The bacterium sp QY4 was named Bacillus spp. QY4 strain (sp QY4). Ochrobactrum sp. QY4). This *Aureobacterium* genus QY4 ( Ochrobactrum This strain (sp. QY4) was deposited on January 8, 2026, at the China Center for Type Culture Collection (CCTCC), located at No. 299 Bayi Road, Wuchang District, Wuhan City, Hubei Province, with accession number CCTCC NO: M2026052. After identification, the bacteria in subsequent examples will be referred to as *Ailuropoda* strain QY4.
[0048] Example 2: Growth of *Alanium* strain QY4 in isolation and purification media with different concentrations of PET The tolerance threshold of *Acanthocephala* strain QY4 to aging extracts of PET at different concentrations was verified in 12-well plates. The specific procedure was as follows: First, different concentrations of PET were set (0, 1 mg / L, 20 mg / L, 100 mg / L, 1000 mg / L, 5000 mg / L, 20000 mg / L). Then, single colonies of *Acanthocephala* strain QY4 were streaked onto purification media of different PET concentrations and incubated at 30 ℃ in a shaker for 2-7 days. Colony growth was observed and photographed to determine the concentration range of PET plastics from which colonies could grow.
[0049] The experimental results are available in [reference]. Figure 1 And Table 1, Figure 1Table 1 shows the colony growth of the *Ailuropoda* strain QY4 proposed in this application at different time points in purified media supplemented with different concentrations of PET aging extract. Figure 1 The corresponding statistical results of colony growth. (From...) Figure 1 It is evident that the *Aureobacterium* strain QY4 cannot grow in a carbon-nitrogen-free medium without PET plastic. Figure 1 The first column of culture media on the left shows the culture medium. However, on the medium containing PET plastic, obvious colonies began to appear from day 2, and there was no significant difference in growth on media with PET plastic concentrations of 1-20000 mg / L. This indicates that *Ailuropoda* strain QY4 can grow using polyethylene terephthalate (PET) plastic as the sole carbon source, and that *Ailuropoda* strain QY4 is tolerant of PET plastic concentrations ranging from 1-20000 mg / L.
[0050] Table 1 shows the statistical results of the corresponding colony growth.
[0051] Note: In Table 1, "-" indicates no growth; "+" indicates growth; "++" indicates good growth; and "+++" indicates excellent growth.
[0052] Example 3: Growth of *Acanthocephala* strain QY4 in degradation media of different concentrations of PET The growth of *Acanthocephala* strain QY4 in different concentrations of PET was verified in a degradation medium with PET microplastic powder as the sole carbon source. PET microplastic powder is more difficult for microorganisms to utilize than the extract of LED UV-aged plastics, therefore it was used to verify the degradation of PET plastics. The specific procedure was as follows: PET concentrations were set at 1 mg / L, 20 mg / L, 100 mg / L, 1000 mg / L, 5000 mg / L, and 20000 mg / L. Single colonies of *Acanthocephala* strain QY4 were streaked onto degradation media with different PET concentrations and incubated at 30 ℃ in a shaker for 2-10 days. Colony growth was observed and photographed to determine the range of PET concentrations in which colonies could grow.
[0053] The degradation culture media with different PET concentrations were prepared as follows: 1 g KH2PO4, 3 g K2HPO4·3H2O, 0.2 g MgSO4, 1 g NaCl, 0.01 g CaCl2, 0.006 g Na2SeO3·5H2O, 0.008 g Na2WO4·2H2O, 0.0005 g EDTA, 0.0002 g FeSO4·7H2O, 0.00001 g ZnSO4·7H2O, 0.000003 g MnCl2·4H2O, 0.00003 g H3BO3, 0.00002 g CoCl2·6H2O, 0.000001 g CuCl2·2H2O, 0.000002 g NiCl2·6H2O, 0.000003 g NaMoO4·2H2O, 15 Add g of agar, mix thoroughly, and then bring the volume to 1 L with ultrapure water. After high-temperature and high-pressure sterilization, add different concentrations of PET microplastic powder, mix well, and cool to solidify for later use.
[0054] The growth results of the *Acanthocephala* strain QY4 are as follows: Figure 2 As shown, Figure 2 This paper demonstrates the colony formation of the *Ailuropoda* strain QY4 at different growth times in degradation media containing varying concentrations of PET microplastic powder. The *Ailuropoda* strain QY4 grew well on degradation media containing PET at concentrations ranging from 1 to 20,000 mg / L, forming distinct colonies in all cases, indicating that the *Ailuropoda* strain QY4 can grow using PET plastic as the sole carbon source.
[0055] Example 4: Plastic degradation performance of *Acanthocephala* strain QY4 - Infrared spectroscopy Taking PET plastic as an example, the plastic degradation performance of the *Acanthocephala* strain QY4 was explained. A single colony of *Acanthocephala* strain QY4 was streaked on a degradation medium with a PET concentration of 1000 mg / L and incubated in a constant temperature shaker at 30 ℃. After 7 days of degradation of PET plastic by *Acanthocephala* strain QY4, the changes in surface functional groups before and after degradation of PET plastic by *Acanthocephala* strain QY4 were measured by Fourier Transform Infrared (FTIR).
[0056] The spectral measurement range is 400–4000 cm⁻¹ 1 The result is as follows Figure 3 As shown, Figure 3The images show the infrared spectra of the control group and the treatment group treated with *Ailuropoda spp.* strain QY4 in this application. The upper image shows the control group with only PET plastic added (i.e., PET microplastic powder added only to the degradation medium), and the lower image shows the treatment group with both *Ailuropoda spp.* strain QY4 and PET plastic added (i.e., PET microplastic powder and *Ailuropoda spp.* strain QY4 added to the degradation medium). Compared with the control group, the treated group samples showed higher wavelengths at 3200–3600 cm⁻¹. -1 The broad O–H peaks were significantly enhanced, while the peaks at 1730–1715 cm⁻¹ were also significantly enhanced. -1 (Ester C=O) and 1260–1230 / 1170–1100cm -1 (C–O / C–O–C) decreased significantly, and a range of 1685–1700 cm was observed. -1 (Carboxylic acid C=O) and 1560–1610, 1410–1440 cm -1 (Carboxylate COO) - The characteristic bands indicate that the ester bonds in PET are hydrolyzed, generating carboxyl / hydroxyl-containing products such as TPA (terephthalic acid), terephthalic acid / monoethyl hydroxylate / ethylene glycol; simultaneously, 1650 / 1540 cm⁻¹ -1 The presence of amide bands suggests biofilm / protein adsorption, which comprehensively proves that the PET plastic has undergone bio-induced degradation.
[0057] Example 5: Degradation performance of PET plastic by *Acanthocephala* strain QY4 - Differential Scanning Calorimetry (DSC) Differential scanning calorimetry (DSC) is used to characterize the effects of plastic-degrading bacteria on the isothermal properties of PET matrix, including crystallization and melting. The peak changes during heating and cooling scans are shown in the control group (PET plastic only) and the treatment group (PET plastic and *Acanthocephala* strain QY4). Figure 4 As shown (the control and treatment groups were treated in the same way as in Example 4, and will not be repeated here). Compared with the control group, the molecular weight of the treated samples decreased (glass transition Tg decreased), the crystal structure was destroyed (melting Tm decreased, crystallinity may have decreased), and the thermal stability of the material deteriorated. These changes are completely consistent with the conclusions of FTIR analysis (ester bond breakage, generating carboxylic acids and alcohols), together depicting a complete picture: microorganisms attacked and broke the molecular chains of PET, causing its molecular weight to decrease and destroying its original supramolecular structure, ultimately leading to the loss of macroscopic properties of the material (such as mechanical strength and thermal stability). This is consistent with the thermal characteristics of PET bio-enzymatic degradation, indicating that PET plastic underwent biodegradation under the action of the strain.
[0058] Example 6: Plastic degradation performance of *Acanthocephala* strain QY4 - pyrolysis chromatography-mass spectrometry Rupture chromatography-mass spectrometry was used to characterize the degradation products of PET under the action of plastic-degrading bacteria. The results of screening for differences between the control group (containing only PET plastic) and the treatment group (containing both PET plastic and *Acanthocephala* strain QY4) and comparing the products are shown below. Figure 5 As shown in the results, the treated samples tested positive for Hexadecanoic acid, 2-hydroxyethyl ester (indicating ethylene glycol-involved transesterification / esterification), and ethylenedioxime (indicating oxidative cleavage of ethylene glycol). Both indicate that the ethylene glycol end groups released during PET hydrolysis were present and further transformed. Mono(2-ethylhexyl) phthalate indicates the presence of phthalate degradation products in the system, suggesting that the plasticizer has been attacked and partially hydrolyzed by microorganisms, indirectly indicating that the PET system is in an active biodegradation environment. This is completely consistent with the conclusions of FTIR (detection of ester bond reduction and carboxyl group formation) and DSC (detection of molecular weight decrease and crystal structure destruction), forming a complete chain of evidence confirming the biodegradation process of PET.
[0059] In summary, this application provides bacteria of the genus *Acanthocephala*, their inoculants, applications, and methods. The *Acanthocephala* bacteria provided in this application are *Acanthocephala* genus QY4 (… Ochrobactrum The strain *Acanthocephala* sp. QY4, with accession number CCTCC NO: M2026052, possesses plastic degradation capabilities, specifically capable of degrading polyethylene terephthalate (PET) plastics. Experiments show that this application successfully isolated and screened *Acanthocephala* sp. QY4 from plastic-contaminated soil in an Inner Mongolia landfill. This strain can grow using PET plastic as its sole carbon source. Difference peaks in the infrared spectrum indicate that after treatment with the strain, the ester bonds in PET break, generating carboxylic acids and alcohols. Differential scanning calorimetry (DSC) shows that the strain reduces the molecular weight and disrupts the crystal structure of PET plastic. Products detected by pyrolysis chromatography-mass spectrometry support the release of ethylene glycol and other substances from the hydrolysis of PET under the strain's action. All these findings demonstrate that *Acanthocephala* sp. QY4 utilizes PET plastic as a carbon source and possesses plastic degradation capabilities.
[0060] The above provides a detailed description of a bacterium of the genus *Acanthocephala*, its inoculum, its application, and the method provided in this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.
Claims
1. A bacterium of the genus *Pseudomonas*, characterized in that, The strain of *Ailuropoda* is *Ailuropoda* QY4 (… Ochrobactrum The strain (spe. QY4) has the accession number CCTCC NO: M 2026052.
2. A microbial agent, characterized in that, The bacterial agent comprises the *Alanium* bacteria as described in claim 1.
3. The microbial agent according to claim 2, characterized in that, The bacterial agent contains the *Alanium* bacteria as described in claim 1 as an active ingredient.
4. The application of a bacterium of the genus *Acanthocephala* as described in claim 1 or an agent of bacteria as described in claim 2 or 3 in the degradation of plastics.
5. The application according to claim 4, characterized in that, The degradation process involves growing plastic using plastic as the sole carbon source, gradually degrading the plastic.
6. The application according to claim 5, characterized in that, The plastic exists in the form of granules, films, or powders.
7. The application according to any one of claims 5-6, characterized in that, The plastic is polyethylene terephthalate (PET) plastic.
8. The application according to claim 7, characterized in that, The bacteria of the genus *Alanium* degraded polyethylene terephthalate in various aquatic environments.
9. A method for degrading polyethylene terephthalate, characterized in that, The bacteria of the genus *Alanium* as described in claim 1 or the bacterial agent as described in any one of claims 2-3 are co-cultured with polyethylene terephthalate.