Acinetobacter baumannii H5 and application thereof

Abstract

The invention discloses an Acinetobacter baumannii H5 strain and application thereof, the Acinetobacter baumannii H5 strain is preserved in the Guangdong Microbial Culture Collection Center on September 29, 2024, and the preservation number is GDMCC (China General Microbiological Culture Collection Center) NO: 65133; and the strain has a good degradation effect on polyethylene glycol terephthalate plastics. As the spodoptera frugiperda is a recently occurring major invading pest, domestic and overseas scholars are very limited in research on intestinal microorganisms of the spodoptera frugiperda, no related report about that intestinal strains of the spodoptera frugiperda can effectively degrade polyethylene glycol terephthalate exists at present, and the research on the degradation mechanism of the spodoptera frugiperda is also relatively lacked. The Acinetobacter baumannii H5 can enrich a plastic degradation microorganism germplasm resource library, provides the most basic resource for the technical breakthrough of polyethylene glycol terephthalate biodegradation, and also can optimize the ecological environment protection.

Description

Technical Field

[0001] The invention belongs to the technical field of microbial degradation, and specifically relates to a strain of Acinetobacter baumannii H5 and an application thereof. Background Art

[0002] Plastics are polymer compounds that are made of natural or synthetic resins through addition polymerization or condensation polymerization. Among them, polyethylene terephthalate is synthesized by esterification and condensation polymerization of terephthalic acid and ethylene glycol. It has become one of the most widely used materials in the world because of its durability, high transparency, light weight, high tensile impact strength, chemical resistance and processability. It is mainly used in container packaging, such as beverage bottles and food packaging bags. Due to long-term exposure of polyethylene terephthalate to soil and sludge sediments, it enters the ocean through various channels, posing a serious threat to the global ecological environment. Scientists have detected polyethylene terephthalate fragments in nearly 700 marine organisms. The accumulation of these fragments leads to endocrine disorders, developmental delays, cell necrosis, and damage to immune cells in organisms. In addition, polyethylene terephthalate fragments or particles in organisms will threaten human health as they are enriched in the food chain. Therefore, how to effectively degrade polyethylene terephthalate has become a hot issue of common concern in society.

[0003] Compared with physical and chemical methods, the biodegradation of plastics has the advantages of easy operation, environmental friendliness, low energy consumption and green environmental protection. Therefore, the biodegradation of plastics is considered to be the most promising method. At present, biodegradable plastics are mainly degraded by insects, microorganisms and enzymes. Studies have shown that some lepidopteran and coleopteran insect larvae can effectively chew and ingest plastics and show good plastic degradation potential. Since most studies are limited to specific insects and plastic materials, there are few reports on the biodegradation of polyethylene terephthalate by insect-derived microorganisms, and the degradation efficiency of insects varies greatly due to the different physical and chemical properties of plastics. The fall armyworm has the characteristics of a wide host range, strong reproductive capacity, and long migration distance. It is a major pest of grain crops in the world. It was first discovered in Yunnan, my country in January 2019 and quickly spread to more than 20 provinces and cities. Because the fall armyworm feeds on corn leaves during the larval stage, it causes large-scale leaf fall, destroys corn husks, and destroys the growth potential of corn plants. China is one of the world's largest corn producers. With the invasion of fall armyworm, China's food security and agricultural production are facing great risks. Therefore, fall armyworm is included in my country's "List of Class I Crop Pests and Diseases". Since fall armyworm is a major invasive pest that has recently occurred, domestic and foreign scholars have conducted very limited research on its intestinal microorganisms. There is currently no report that the intestinal flora of fall armyworm larvae can effectively degrade polyethylene terephthalate. Therefore, the fall armyworm intestine was selected as the research object to screen microorganisms that can degrade polyethylene terephthalate in its intestine. Summary of the invention

[0004] The present invention isolates and screens a strain of Acinetobacter baumannii from the intestine of the larvae of Spodoptera frugiperda, and names it Acinetobacter baumannii ( Acinetobacter baumannii )H5, which can effectively degrade polyethylene terephthalate.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows: The first object of the present invention is to provide a strain of Acinetobacter baumannii ( Acinetobacter baumannii ) H5 strain, which was deposited in Guangdong Microbiological Culture Collection Center on September 29, 2024, with a deposit number of GDMCC NO: 65133. The 16S rDNA sequence of the H5 strain is shown in SEQ ID No: 1: SEQ ID No: 1

[0006] The second object of the present invention is to use the H5 strain or its bacterial solution in degrading polyethylene terephthalate or in plastic products made of polyethylene terephthalate.

[0007] Furthermore, Acinetobacter baumannii ( Acinetobacter baumannii ) The suitable culture temperature for H5 strain is 35℃.

[0008] The third object of the present invention is to provide a method for degrading polyethylene terephthalate plastics, firstly, the Acinetobacter baumannii ( Acinetobacter baumannii ) The H5 strain was prepared into a bacterial liquid, which was then put into an inorganic salt liquid culture medium containing polyethylene terephthalate plastic to degrade microplastics.

[0009] Furthermore, Acinetobacter baumannii ( Acinetobacter baumannii )The method for preparing the H5 strain into bacterial liquid is specifically as follows: Acinetobacter baumannii ( Acinetobacter baumannii ) After the H5 strain was cultured in LB medium for 12-16 h, the cells were collected by centrifugation, then rinsed with inorganic salt medium to remove the residual LB medium, and finally resuspended in inorganic salt medium. The inorganic salt medium included K2HPO40.7 g / L, KH2PO40.7 g / L, MgSO4·7H2O 0.7 g / L, NH4NO31.0 g / L, NaCl 0.005 g / L, FeSO4·7H2O 0.002 g / L, ZnSO4·7H2O 0.002 g / L, and MnSO4·H2O 0.001 g / L, prepared with ultrapure water, and the pH value was adjusted to 7.0.

[0010] Furthermore, the liquid inorganic salt culture medium includes K2HPO40.7 g / L, KH2PO40.7 g / L, MgSO4·7H2O0.7 g / L, NH4NO31.0 g / L, NaCl 0.005 g / L, FeSO4·7H2O 0.002 g / L, ZnSO4·7H2O 0.002 g / L, and MnSO4·H2O 0.001 g / L, and is prepared with ultrapure water, with an optimal pH of 7.

[0011] The third object of the present invention is to provide a bacterial agent for degrading microplastics, wherein the bacterial agent is the Acinetobacter baumannii ( Acinetobacter baumannii ) H5 as the main active ingredient.

[0012] The following beneficial effects can be obtained through the above technical solution: The present invention isolated and screened a microplastic-degrading bacterial strain from the intestine of the fall armyworm larvae and named it Acinetobacter baumannii ( Acinetobacter baumannii )H5, and this strain has a good degradation effect on polyethylene terephthalate plastic. Since the fall armyworm is a major invasive pest that has recently occurred, domestic and foreign scholars have limited research on its intestinal microorganisms. Currently, there is no report that the fall armyworm intestinal strain can effectively degrade polyethylene terephthalate, and research on its degradation mechanism is relatively lacking. Acinetobacter baumannii ) H5 can enrich the germplasm resource bank of plastic-degrading microorganisms, provide the most basic resources for technological breakthroughs in the biodegradation of polyethylene terephthalate, and optimize ecological environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is the weight loss graph of polyethylene terephthalate film after strain H5 treatment; Figure 2 This is the colony morphology of strain H5; Figure 3 is the scanning electron micrograph of strain H5; Figure 4 is the phylogenetic tree of strain H5; Figure 5 (a) is the effect of temperature on the growth of strain H5; (b) is the effect of pH on the growth of strain H5; (c) is the effect of NaCl concentration on the growth of H5; (d) is the growth curve of strain H5; Figure 6 is a scanning electron micrograph of the polyethylene terephthalate film treated with strain H5; Figure 7 is a scanning electron micrograph of polyethylene terephthalate particles treated with strain H5; Figure 8 is the Fourier transform infrared spectrum of polyethylene terephthalate particles treated with strain H5; Fig. 9 is the HPLC chromatogram of polyethylene terephthalate particles treated with strain H5. DETAILED DESCRIPTION

[0014] The present invention will be further described below in conjunction with the accompanying drawings: The present invention provides a strain of Acinetobacter baumannii ( Acinetobacter baumannii ) H5 strain, which was deposited in Guangdong Provincial Microbiological Culture Collection Center on September 29, 2024, with the deposit number GDMCC NO: 65133.

[0015] Isolation and screening of strain H5 Initial screening: The larvae of Spodoptera frugiperda were used as the research objects. The larvae with polyethylene terephthalate as the food source were set as the experimental group, and the larvae with feed as the food source were set as the control group. Each group was repeated 3 times, and each repeat had 100 larvae. The larvae were starved for 24 hours before the experiment. After the experiment, they were incubated in a constant temperature and humidity incubator for 7 days. After 7 days, the surviving larvae in the experimental group with polyethylene terephthalate as the food source were washed with 70% (v / v) ethanol to remove surface pollutants and washed twice with sterile water. The digestive tract was dissected, and the intestinal contents were placed in an inorganic salt culture medium containing polyethylene terephthalate particles. Three parallel groups were set up and cultured at 30°C and 180 rpm for 6 days. After 6 days, 10 ml of the enrichment solution was taken and placed in a new 100 ml inorganic salt culture medium containing polyethylene terephthalate particles, and the same conditions were used for 5 cycles. Take the fifth enrichment solution and dilute it appropriately, take 200 μL of 10 -1 , 10 -2 , 10 -3 , 10 -4 , 10 -5 and 10 -6 The diluted solution was evenly spread on a -1 The polyethylene terephthalate particles were placed on an inorganic salt solid medium in a 30°C incubator until colonies grew out. According to the size of the colonies, several strains with good growth were selected, separated and purified on an inorganic salt solid medium, and stored.

[0016] Rescreening: Inoculate the strains obtained from the initial screening into LB medium in a clean bench, culture at 35°C, 180rpm for 12-16 hours, and obtain a bacterial solution with a bacterial density of OD600 of 1. Take 50 ml of the above LB bacterial solution in a centrifuge tube, centrifuge at 8000 rpm for 10 min, remove the supernatant, add 5 ml of sterile 0.9% NaCl solution and centrifuge, remove the supernatant, repeat twice, and finally add 5 ml of sterile 0.9% NaCl, mix the bacterial solution and inoculate it into 100 ml of inorganic salt liquid culture medium containing sterile polyethylene terephthalate film at a 10-25% inoculation amount. Set up 3 parallel groups (with no bacteria added as the control group), 35°C, 180 r·min -1 The weight loss of polyethylene terephthalate film was analyzed after culturing for 6 days under the same conditions. Figure 1 ,After 6 days of cultivation, polyethylene terephthalate produced obvious mass loss under the action of H5.

[0017] Among them, the preparation process of polyethylene terephthalate plastic is as follows: (1) Preparation of polyethylene terephthalate particles: 200-mesh polyethylene terephthalate particles were purchased from Taobao Mingyan Plastic Flagship Store, and were soaked in 75% ethanol for 10 min. The particles were then rinsed with sterile ultrapure water for 3-4 times and dried in a clean bench for later use.

[0018] (2) Preparation of polyethylene terephthalate film: The polyethylene terephthalate film purchased from Taobao's flagship store of high temperature resistant insulation materials was evenly cut into small pieces of 10 × 10 mm, immersed in 75% ethanol for 10 min, then rinsed with ultrapure water for 3-4 times, and dried on a clean bench for later use.

[0019] (3) The LB liquid medium used was prepared with 10 g / L peptone, 5 g / L yeast, 10 g / L sodium chloride, and ultrapure water, and the pH was adjusted to 7.0.

[0020] (4) The liquid inorganic salt culture medium used includes K2HPO4 0.7 g / L, KH2PO4 0.7 g / L, MgSO4·7H2O 0.7 g / L, NH4NO3 1.0 g / L, NaCl 0.005 g / L, FeSO4·7H2O 0.002 g / L, ZnSO4·7H2O 0.002 g / L, MnSO4·H2O 0.001 g / L, prepared with ultrapure water, pH 7. Add 20 g / L agar to obtain the inorganic salt solid culture medium.

[0021] 2. Morphological characteristics of strain H5 Inoculate the strain into LB liquid medium and culture at 35 ℃ for 12-16 h. Use an inoculation loop to inoculate into LB solid medium and culture in a 30 ℃ incubator for 24 h. Observe the morphological characteristics of the strain, such as Figure 2 As shown, the colonies of H5 were round, white, opaque, with a smooth, convex surface and regular edges. Figure 3 This is a scanning electron micrograph of strain H5.

[0022] 3. Molecular biological identification of strain H5 2 mL of bacterial solution cultured for 12-16 h was added to a 2 mL EP tube and centrifuged at 8000 rpm for 2 min. The gene of strain H5 was extracted according to the bacterial DNA extraction kit and amplified using PCR technology.

[0023] (1) Genome: The genome of strain H5 was extracted using a bacterial DNA extraction kit (Tiangen Biochemical Technology Co., Ltd.).

[0024] (2) Primers: 27F and 1492R (Sangon Biotechnology Co., Ltd.) (3) PCR reaction system (50 μL): Taq PCR Master Mix 25 μL, DNA template 1 μL, 27F2 μL, 1492R 2 μL, ddH2O 20 μL.

[0025] (4) Reaction procedure: 30 cycles of denaturation at 94 °C for 30 s, annealing at 55 °C for 30 s, and extension at 72 °C for 90 s; extension at 72 °C for 10 min; and storage at 4 °C.

[0026] (5) Agarose gel electrophoresis: The product obtained by PCR amplification was electrophoresed on 1% agarose gel until a single bright band appeared, and then sent to Shanghai Meiji Biotechnology Co., Ltd. for sequencing.

[0027] (6) Phylogenetic tree: The bacterial 16S rRNA sequence of the sequencing results was compared with the homology in the NCBI database, and the phylogenetic tree of strain H5 was drawn using MEGA 11 software. It was found that the strain had the highest similarity with Acinetobacter baumannii, which was 100%. Figure 4 shown.

[0028] (7) Strain H5 16S rDNA sequence: SEQ ID No: 1

[0029] Strain H5 was inoculated into 100 ml of LB medium at a 1% inoculum size and cultured at 35°C and 180 rpm for 12-16 h to obtain a seed solution with an OD600 of 1 for subsequent experiments.

[0030] Effect of temperature on the growth of strain H5 Using the controlled variable method, the seed solution was inoculated with 1% inoculum into LB liquid culture medium at 20℃, 25℃, 30℃, 35℃, 40℃, and 45℃, and the OD value of the strain at an absorbance of 600 was measured every 2 hours. Each group was repeated three times. The growth of strain H5 under each culture temperature condition was compared. Figure 5 As shown in (a), 35℃ is the temperature for Acinetobacter baumannii ( Acinetobacter baumannii )H5 is the most suitable temperature.

[0031] Effect of pH on the growth of strain H5 Using the controlled variable method, the seed solution was inoculated with 1% inoculum into LB liquid medium with pH values ​​of 5.0, 6.0, 7.0, 8.0, 9.0, and 10.0, and the OD value of the strain at an absorbance of 600 was measured every 2 hours. Each group was repeated three times. The growth potential of strain H5 under different pH conditions was compared. Figure 5 (b) Acinetobacter baumannii ( Acinetobacter baumannii ) H5 can grow at pH 5.0-10.0, and the optimal growth pH is 7.0.

[0032] Effect of NaCl concentration on the growth of strain H5 Using the controlled variable method, the seed solution was inoculated with 1% inoculum into LB liquid medium with different NaCl concentrations of 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, and 10%. The OD value of the strain at an absorbance of 600 was measured every 2 hours, and each group was repeated three times. The growth potential of strain H5 under different NaCl concentrations was compared. Figure 5 (c) Acinetobacter baumannii ( Acinetobacter baumannii ) The suitable NaCl concentration for the growth of H5 is 1%.

[0033] Growth curve of strain H5 under optimal conditions The growth curve of strain H5 was determined according to the optimal growth conditions obtained above. The strain was cultured in LB liquid medium, and the OD value of the strain at an absorbance of 600 was measured every 2 hours. Each group was repeated three times. The obtained growth curve is shown in Figure 5 (d).

[0034] The LB liquid culture medium used was prepared with 10 g / L peptone, 5 g / L yeast, 10 g / L sodium chloride, and ultrapure water, with a pH of 7.0.

[0035] The inoculation amount of the bacterial solution each time was 1%.

[0036] Among them, the preparation process of polyethylene terephthalate plastic is as follows: (1) Preparation of polyethylene terephthalate particles: 200-mesh polyethylene terephthalate particles were purchased from Taobao Mingyan Plastic Flagship Store, and were soaked in 75% ethanol for 10 min. The particles were then rinsed with sterile ultrapure water for 3-4 times and dried in a clean bench for later use.

[0037] (2) Preparation of polyethylene terephthalate film: The polyethylene terephthalate film purchased from Taobao's flagship store of high temperature resistant insulation materials was evenly cut into small pieces of 10 × 10 mm, immersed in 75% ethanol for 10 min, then rinsed with ultrapure water for 3-4 times, and dried on a clean bench for later use.

[0038] (3) The LB liquid medium used was prepared with 10 g / L peptone, 5 g / L yeast, 10 g / L sodium chloride, and ultrapure water, and the pH was adjusted to 7.0.

[0039] (4) The liquid inorganic salt culture medium used includes K2HPO4 0.7 g / L, KH2PO4 0.7 g / L, MgSO4·7H2O 0.7 g / L, NH4NO3 1.0 g / L, NaCl 0.005 g / L, FeSO4·7H2O 0.002 g / L, ZnSO4·7H2O 0.002 g / L, MnSO4·H2O 0.001 g / L, prepared with ultrapure water, pH 7. Add 20 g / L agar to obtain the inorganic salt solid culture medium.

[0040] 2. Experimental methods: 2.1 Experimental methods for polyethylene terephthalate films Strain H5 was cultured at 35°C and 180 rpm for 12-16 h to obtain a bacterial solution with a bacterial density of OD600 of 1. Take 50 ml of the above LB bacterial solution in a centrifuge tube, centrifuge at 8000 rpm for 10 min, remove the supernatant, add 5 ml of sterile 0.9% NaCl solution and centrifuge, remove the supernatant, repeat twice, and finally add 5 ml of sterile 0.9% NaCl, mix the bacterial solution and inoculate it into 100 ml of inorganic salt liquid culture medium containing sterile polyethylene terephthalate plastic film at a 10-25% inoculation amount. Set up 3 parallel groups (with no bacteria added as the control group), 35°C, 180 r·min-1 The film was cultured for 3-6 days under the same conditions. The weight loss rate, scanning electron microscopy (SEM), and water contact angle of the polyethylene terephthalate plastic film were analyzed.

[0041] 2.1 Experimental methods for polyethylene terephthalate particles Strain H5 was cultured at 35°C and 180 rpm for 12-16 h to obtain a bacterial solution with a bacterial density of OD600 of 1. Take 50 ml of the above LB bacterial solution in a centrifuge tube, centrifuge at 8000 rpm for 10 min, remove the supernatant, add 5 ml of sterile 0.9% NaCl solution and centrifuge, remove the supernatant, repeat twice, and finally add 5 ml of sterile 0.9% NaCl, mix the bacterial solution and inoculate it into 100 ml of inorganic salt liquid culture medium containing sterile polyethylene terephthalate particles at a 10-25% inoculation amount. Set up 3 parallel groups (with no bacteria added as the control group), 35°C, 180 r·min -1 The pellets were cultured for 3-6 days under the same conditions. The weight loss rate, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and high performance liquid chromatography (HPLC) were used to analyze the polyethylene terephthalate pellets.

[0042] Analysis method for polyethylene terephthalate plastics: (1) The polyethylene terephthalate film treated with strain H5 was repeatedly washed with deionized water for 3-5 times, washed and soaked with 1% SDS solution, placed in an ultrasonic cleaner for 30 min, and then washed several times with 20% anhydrous ethanol. Finally, it was placed in an oven for drying at 60°C. After that, the polyethylene terephthalate film was fixed and sprayed with gold, and its microscopic morphology was observed under a scanning electron microscope.

[0043] (2) The polyethylene terephthalate particles treated with strain H5 were repeatedly washed with deionized water for 3-5 times, washed and soaked with 1% SDS solution, placed in an ultrasonic cleaner for 30 min, and then washed several times with 20% anhydrous ethanol. Finally, they were placed in an oven for drying at 60°C. After that, the polyethylene terephthalate particles were fixed and sprayed with gold, and their microscopic morphology changes were observed under a scanning electron microscope.

[0044] (3) The polyethylene terephthalate particles treated with strain H5 were repeatedly washed with deionized water for 3-5 times, washed and soaked with 1% SDS solution, placed in an ultrasonic cleaner for 30 min, and then washed several times with 20% anhydrous ethanol. Finally, they were dried in an oven at 60°C. Fourier transform infrared spectroscopy was used to detect changes in the surface functional group structure of the polyethylene terephthalate particles.

[0045] (4) Collect the inorganic salt culture medium of polyethylene terephthalate particles treated with strain H5 for 3 days and 6 days and the inorganic salt culture medium without inoculation of strain H5 (100 ml), centrifuge at 8000 rpm, 10 min, 4 °C to remove cells, and retain the supernatant. Adjust the supernatant to pH 2.0 with 2.0 M HCl and extract once with 100 mL ethyl acetate. Recover the ethyl acetate layer and evaporate on a rotary evaporator. Dissolve the residue in 2.0 ml methanol, filter through a 0.22 μm pore size filter, and perform high performance liquid chromatography (HPLC) analysis. The analytical column is Agilent TC-C18 (2) (250×4.6 mm). The mobile phase is 60% methanol: 40% 20 mM potassium dihydrogen phosphate solution, the column temperature is 35 °C, the flow rate is 0.5 ml / min, and the effluent is monitored at a wavelength of 240 nm. Three typical polyethylene terephthalate degradation products: polyethylene terephthalate degradation products (monohydroxyethylterephthalate (MHET), bishydroxyethyl terephthalate (BHET) and terephthalic acid (TPA)) were dissolved in dimethyl sulfoxide and used as standards.

[0046] 4. Experimental results: 4.1 Analysis of the degradation characteristics of polyethylene terephthalate film by strain H5 pass Figure 6 As shown in (a)-(c), the surface of the polyethylene terephthalate film in the control group is smooth. Figure 6 As shown in (d)-(f), cracks appeared on the surface of the polyethylene terephthalate film after being treated with strain H5, and obvious signs of erosion appeared. The above results indicate that strain H5 has a degradation effect on polyethylene terephthalate film.

[0047] 4.2 Analysis of the degradation characteristics of strain H5 on polyethylene terephthalate particles pass Figure 7 As shown in (a)-(c), the surface of the polyethylene terephthalate particles in the control group is smooth and complete. Figure 7 As shown in (d)-(f), the surface of the polyethylene terephthalate particles treated with strain H5 was severely eroded, with some grooves and roughness. The above results show that strain H5 has a significant degradation effect on polyethylene terephthalate particles.

[0048] Polyethylene terephthalate plastic is a polyester compound, and the ester bond is the most critical functional group, which is between 1000-1300 cm-1 There are two characteristic peaks between 1700 and 1750 cm -1 There is a characteristic peak between Figure 8 It can be seen that the changes in the functional groups on the surface of polyethylene terephthalate particles were detected by Fourier transform infrared spectroscopy. The results showed that the two characteristic peaks of polyethylene terephthalate plastic (carbonyl peak (C=O, 1720 cm -1 ) and alkoxy peak (CO, 1250 cm -1 and 1020 cm -1 )) The peak value was significantly reduced. The above results showed that strain H5 had a significant degradation effect on polyethylene terephthalate particles.

[0049] pass Fig. 9 It can be seen that there are three typical degradation products in the inorganic salt medium of polyethylene terephthalate particles treated with strain H5, namely (monohydroxyethylterephthalate (MHET), bishydroxyethyl terephthalate (BHET) and terephthalic acid (TPA)). The above results show that strain H5 has a significant degradation effect on polyethylene terephthalate particles.

[0050] In summary, the present invention isolated and screened a polyethylene terephthalate plastic-degrading bacterium from the intestine of the fall armyworm larvae and named it Acinetobacter baumannii ( Acinetobacter_baumannii ) H5 strain, which has a good degradation effect on polyethylene terephthalate film and polyethylene terephthalate particles, and shows great application prospects in the biodegradation of polyethylene terephthalate plastics. The above are all preferred embodiments of the present invention. For ordinary technicians in this technical field, without departing from the principle of the present invention, various modifications to the present invention in equivalent forms belong to the protection scope of the claims attached to this application.

Claims

1. A strain of Acinetobacter baumannii ( Acinetobacter baumannii ) H5 strain, characterized in that: The strain was deposited in the Guangdong Provincial Microbiological Culture Collection Center on September 29, 2024, with the collection number GDMCC NO: 65133. The 16S rDNA sequence of the H5 strain is shown in SEQ ID No:

1.

2. Use of the H5 strain or its bacterial solution according to claim 1 in degrading polyethylene terephthalate or in plastic products made of polyethylene terephthalate.

3. A strain of Acinetobacter baumannii according to claim 1 ( Acinetobacter baumannii ) H5 strain, characterized in that: Acinetobacter baumannii ( Acinetobacter baumannii ) The suitable culture temperature for H5 strain is 35℃.

4. A method for degrading polyethylene terephthalate plastic, characterized in that: First, the Acinetobacter baumannii ( Acinetobacter baumannii ) The H5 strain was prepared into a bacterial liquid, which was then put into an inorganic salt liquid culture medium containing polyethylene terephthalate plastic to degrade microplastics.

5. A method for degrading polyethylene terephthalate plastic according to claim 4, characterized in that: Acinetobacter baumannii ( Acinetobacter baumannii )The method for preparing the H5 strain into bacterial liquid is specifically as follows: Acinetobacter baumannii ( Acinetobacter baumannii ) After the H5 strain was cultured in LB medium for 12-16 h, the cells were collected by centrifugation, then rinsed with inorganic salt medium to remove the residual LB medium, and finally resuspended in inorganic salt medium. The inorganic salt medium included K2HPO4 0.7 g / L, KH2PO4 0.7 g / L, MgSO4·7H2O 0.7 g / L, NH4NO3 1.0 g / L, NaCl 0.005 g / L, FeSO4·7H2O 0.002 g / L, ZnSO4·7H2O 0.002 g / L, and MnSO4·H2O 0.001 g / L, prepared with ultrapure water, and the pH value was adjusted to 7.

0.

6. A method for degrading polyethylene terephthalate plastic according to claim 4, characterized in that: Liquid inorganic salt culture medium, including K2HPO4 0.7 g / L, KH2PO4 0.7 g / L, MgSO4·7H2O 0.7 g / L, NH4NO3 1.0g / L, NaCl 0.005 g / L, FeSO4·7H2O 0.002 g / L, ZnSO4·7H2O 0.002 g / L, MnSO4·H2O 0.001g / L, prepared with ultrapure water, and the pH value was adjusted to 7.

0.

7. A bacterial agent for degrading microplastics, characterized in that: The bacterial agent is the Acinetobacter baumannii ( Acinetobacter baumannii ) H5 as the main active ingredient.

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