Novel microorganism having plastic degradation activity and use thereof

Abstract

The present invention relates to a novel microorganism capable of degrading plastics and a method for degrading plastics using the same. The microorganism is capable of degrading one or more types of plastics selected from the group consisting of polyethylene terephthalate (PET), polyvinyl chloride (PVC), polystyrene (PS), polypropylene (PP), polyurethane (PU) and polyethylene (PE) into low molecular weight substances under appropriate culture conditions.

Description

Technical Field

[0001] The present invention relates to a novel microorganism capable of degrading various plastics and a method for degrading plastics using the microorganism. Background Art

[0002] Due to its light weight, high physical and chemical durability, good processability, and extremely low price, the use of plastics has increased rapidly, and the plastic production has increased significantly from 234 million tons in 2000 to 460 million tons in 2019. In addition, the amount of plastic waste generated during the same period increased from 156 million tons to 353 million tons, more than doubling (Korea Institute for International Economic Policy (KIEP), World Economic Focus, Vol. 5, No. 13, Current Status and Impact of International Plastic Regulations, published on May 9, 2022).

[0003] Due to the COVID-19 lockdown, the global plastic usage decreased by 2.2% in 2020 compared to the previous year. However, as lockdowns were lifted around the world, plastic usage increased again, especially in plastic packaging in the fields of healthcare, personal hygiene plastics, and e-commerce.

[0004] The global recycling rate of plastic waste is only 9%, and the unrecycled plastic waste is being treated by landfilling (50%), illegal dumping (22%), and incineration (19%). In particular, plastics account for 80% of marine litter, and it is expected that by 2040, marine plastic waste will increase from 9 million to 14 million tons per year in 2016 to 23 million to 37 million tons per year. The environmental pollution caused by the influx of plastics not only threatens the ecosystem and human health but also requires additional costs for waste treatment and pollution restoration.

[0005] Therefore, as part of the research on plastic waste treatment methods, research on plastic-degrading microorganisms is being actively carried out. For example, Korean Patent Publication No. 10-0350928 discloses a novel microorganism, Klebsiella pneumoniae CJ-PVAa (Accession No. KFCC-11126), which grows well under aerobic conditions and has enhanced polyvinyl alcohol degradation ability, and discloses a method for treating wastewater containing polyvinyl alcohol using the microorganism. In addition, Korean Patent Publication No. 10-0513931 discloses Microbacterium barkeri LC (Accession No. KCCM 10507) and discloses a method for biodegrading polyvinyl alcohol using the bacterium. Summary of the Invention

[0006] [Technical Problem]

[0007] Based on the above situation, the present inventors conducted research and discovered a novel plastic-degrading microorganism, and isolated a microorganism exhibiting plastic-degrading activity after feeding polyethylene to beetle larvae (Zophobas morio). Through microbial identification, a novel plastic-degrading microorganism, Acinetobacter guillouiae Repla2 strain, was discovered.

[0008] Therefore, an object of the present invention is to provide a novel plastic-degrading microorganism and a method for degrading plastics using the microorganism.

[0009] [Technical Solution]

[0010] To achieve the above object, one aspect of the present invention provides Acinetobacter guillouiae Repla2 strain having plastic-degrading activity, and its deposit number is KACC 81234BP.

[0011] The present inventors isolated a strain of Acinetobacter guillouiae Repla2 from the dominant intestinal microbial community obtained after feeding polyethylene to Zophobas morio for two weeks. The isolated Acinetobacter guillouiae Repla2 strain is capable of degrading various plastics, although the degradation rates vary ( Figure 5 ).

[0012] Therefore, according to one embodiment of the present invention, the plastic is one or more selected from the group consisting of polyethylene terephthalate (PET), polyvinyl chloride (PVC), polystyrene (PS), polypropylene (PP), polyurethane (PU), and polyethylene (PE).

[0013] PET is highly transparent, odorless and tasteless, and thus occupies most of the market for plastic beverage bottles on the market. PVC is a thermoplastic, which is firm, hard or flexible and not easily worn. PVC is used in artificial leather, packaging materials, pipes and electrical insulators, and has been used under the name of vinyl for the longest time.

[0014] PS is a lightweight, odorless and tasteless thermoplastic, which is used in household items, toys, electrical insulators, radio and television casings, packaging materials, etc. PP is polymerized from propylene extracted from petroleum and is widely used in the manufacture of bottles and containers.

[0015] PE is a lightweight and flexible thermoplastic, which is a widely used plastic applied from industrial materials to household items. High-density polyethylene (HDPE) has strong impact resistance and good cold resistance, and is mainly used in the production of shopping bags and pipes. Low-density polyethylene (LDPE) contains branched chains in its polymer, so its density is lower than that of linear HDPE, and due to its good elasticity, it is easy to process.

[0016] In the present invention, "plastic degradation" refers to the degradation of the polymeric materials forming plastics into intermediate materials of low molecular weight or intermediate materials that can be metabolized through microbial metabolic pathways.

[0017] According to one embodiment of the present invention, plastic degradation can be the degradation of the polymeric materials forming plastics into hydrocarbon structural materials having a small molecular weight (Mw of about 500) ([C n H n n ).

[0018] Another aspect of the present invention provides a method for degrading plastics, comprising the step of culturing plastics with Acinetobacter gilvus Repla2 strain with the deposit number KACC 81234BP, the strain culture solution, the strain lysate or the plastic-degrading enzyme derived from the strain.

[0019] According to the embodiment of the present invention, plastics can be degraded in the presence of only the culture solution of Acinetobacter gilvus Repla2 strain ( Figure 8 ), which means that Acinetobacter gilvus Repla2 strain produces and secretes plastic-degrading enzymes. Therefore, the culture solution of Acinetobacter gilvus Repla2 strain, the strain lysate or the isolated plastic-degrading enzyme can also be used to degrade plastics.

[0020] The culturing can be carried out at a temperature of 8°C to 40°C for 7 to 60 days, but is not limited thereto, after inoculating Acinetobacter gilvus Repla2 strain into a medium containing plastics as the sole carbon source. Preferably, the culturing can be carried out at a temperature of 8°C to 37°C for 7 to 30 days.

[0021] The composition of the medium, the culturing temperature, and the culturing time used in the plastic degradation method of the present invention can vary according to the type of plastics to be degraded. When Acinetobacter gilvus Repla2 strain is cultured with waste plastics or plastic-containing waste under the conditions determined by combining these conditions as process parameters, specific plastics can be degraded to a large extent, or all plastics can be degraded into reusable low molecular weight materials.

[0022] The plastics added to the medium can be in the form of thin slices or films (waste vinyl) cut into small pieces to increase the contact with Acinetobacter gilvus Repla2 strain or the plastic-degrading enzyme secreted by the strain.

[0023] Another aspect of the present invention provides a composition for degrading plastics, which comprises Acinetobacter gilvus Repla2 strain with the deposit number KACC81234BP, the strain culture solution, the strain lysate or the plastic-degrading enzyme derived from the strain.

[0024] ​As described above, Acinetobacter gyllenbergii strain Repla2 expresses plastic-degrading enzymes and utilizes plastics as a carbon source. Therefore, the strain itself, the strain culture, the strain lysate, and the strain-derived plastic-degrading enzymes can be effectively used for the purpose of degrading plastics.

[0025] The plastic-degrading enzyme can be an extracellular or intracellular substance of the microorganism, which has plastic-degrading activity and can be mass-produced by various types of gene recombination.

[0026] Acinetobacter gyllenbergii strain Repla2 has a gene ([ Figure 7 ) that is specifically overexpressed during plastic degradation, and this gene can be introduced into other microorganisms by gene recombination, and the recombinant microorganisms can be used for plastic degradation.

[0027] Meanwhile, Acinetobacter gyllenbergii strain Repla2 is capable of degrading various plastic metabolic intermediates (metabolites) generated during plastic degradation ( Figure 2 ).

[0028] Therefore, the present invention provides a composition for degrading plastic metabolic intermediates, which comprises Acinetobacter gyllenbergii strain Repla2 with the accession number KACC81234BP, the strain culture solution, the strain lysate, or the strain-derived plastic-degrading enzyme, and provides a method for degrading plastic metabolic intermediates.

[0029] According to one embodiment of the present invention, the plastic metabolic intermediate is one or more selected from the group consisting of alkanes, alcohols, aldehydes, and fatty acids.

[0030] That is to say, Acinetobacter gyllenbergii strain Repla2 can not only degrade high-molecular-weight plastics into low-molecular-weight monomers, but also gradually degrade the low-molecular-weight monomers into alkanes, alcohols, aldehydes, and fatty acids.

[0031] The present inventors have also confirmed that Acinetobacter gyllenbergii strain Repla2 can hydrophilize the surface of plastic films. Therefore, the present invention provides a composition for promoting plastic oxidation, which comprises Acinetobacter gyllenbergii strain Repla2 with the accession number KACC 81234BP, the strain culture solution, the strain lysate, or the strain-derived plastic-degrading enzyme, and provides a method for promoting plastic oxidation.

[0032] In the present invention, during the plastic degradation process, the composition for degrading plastic metabolic intermediates and the composition for promoting plastic oxidation can be used alone or in combination with other plastic-degrading microorganisms / enzymes.

[0033] [Advantageous Effects]

[0034] The microorganisms with plastic degradation activity according to the present invention can degrade one or more types of plastics selected from the group consisting of polyethylene terephthalate (PET), polyvinyl chloride (PVC), polystyrene (PS), polypropylene (PP), polyurethane (PU), and polyethylene (PE), and convert them into low-molecular-weight substances. Therefore, the microorganisms can be used in plastic degradation and the pretreatment process of plastic recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The results showing the cultivation of Acinetobacter gilvus Repla2 strain (hereinafter referred to as Repla2) with plastic degradation activity in a minimal medium containing polyethylene (PE) powder and using the absorbance of 2,6-dichlorophenolindophenol (DCPIP) to confirm whether Repla2 metabolizes PE. Error bars represent the standard deviation of the mean, and asterisks indicate p < 0.05 (Mann-Whitney rank sum test).

[0036] Figure 2 The results showing the cultivation of Repla2 in a minimal medium containing alkane, alcohol, aldehyde, or fatty acid as the sole energy source and carbon source and confirming whether Repla2 metabolizes the corresponding substances. At = the change in DCPIP absorbance value over time in the minimal medium containing each energy source and carbon source; Act = the change in DCPIP absorbance value over time in the control group (minimal medium without energy source and carbon source); Error bar = the standard deviation of the mean.

[0037] Figure 3 The results showing the cultivation of a strain without plastic degradation activity (Escherichia coli) and a strain with plastic degradation activity (Repla2) in a minimal medium supplemented with plastic powder and confirming the viable cell count. Error bars represent the standard deviation of the mean.

[0038] Figure 4 A shows the results of cultivating in a minimal medium supplemented only with a plastic film but without Repla2 and then confirming the degree of corrosion on the surface of the plastic film.

[0039] Figure 4 B shows the results of cultivating Repla2 in a minimal medium supplemented with a plastic film and then confirming the degree of corrosion on the surface of the plastic film.

[0040] Figure 4 C shows the results of cultivating Repla2 in a minimal medium supplemented with a plastic film and confirming the formation of a microbial biofilm on the surface of the plastic film.

[0041] Figure 5 The results showing the cultivation of Repla2 in a minimal medium containing various types of plastic powder as the sole carbon source and then measuring the plastic degradation rate.

[0042] Figure 6 shows the results of culturing a plastic film with Repla2 and then analyzing the changes in the surface hydrophilicity and chemical functional groups of the plastic film using X-ray photoelectron spectroscopy (a), Fourier transform infrared spectroscopy (b), and a contact angle meter (c).

[0043] Figure 7 The results of confirming the presence of plastic-degrading enzymes in the Repla2 culture solution using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) are shown.

[0044] Figure 8 The results of reacting the Repla2 culture solution with plastic powder for 7 days and confirming the plastic degradation rate are shown. As a control group, the plastic powder was reacted in a basal medium for 7 days. Detailed Description of the Invention

[0045] One or more embodiments are described in more detail below by way of examples. However, these examples are provided for illustrative purposes only, and the scope of the present invention is not limited to these examples.

[0046] Example 1: Isolation of Plastic-Degrading Microorganisms

[0047] 1-1. Isolation of Plastic-Degrading Microorganisms

[0048] By feeding polyethylene (PE) to beetle larvae (Zophobas morio) for two weeks, a selective pressure was applied to hydrocarbon substances that are plastic monomers to obtain the main intestinal microbial community. To isolate only pure intestinal microorganisms, the larvae were disinfected with 70% ethanol and washed with 0.9% saline. After that, the heads and tails of the larvae were removed, the internal organs were taken out, chopped with a sterilized knife, and mixed with saline. The epithelial cells and supernatant were separated by centrifugation.

[0049] A part of the isolated supernatant was inoculated into a basal medium, and microorganisms with potential plastic-degrading activity were cultured by shaking at 180 rpm at 25°C under aerobic conditions with a PE membrane as the sole carbon source and energy source for about 60 days. The composition of the basal medium was as follows: pH 6.51, containing 0.7 g of NH2PO4, 0.7 g of K2HPO4, 0.7 g of MgSO4·7H2O, 1.0 g of NH4NO3, 0.005 g of NaCl, 0.002 g of FeSO4·7H2O, 0.002 g of ZnSO4·7H2O, and 0.001 g of MnSO4·H2O per liter of distilled water. After culturing, 1 strain capable of growing using the PE membrane as a carbon source was isolated by the pure isolation method.

[0050] 1-2. Microbial Identification

[0051] The 16S rRNA base sequence analysis was performed on the pure single strain obtained from the third subculture. The resulting strain was identified as belonging to the genus Acinetobacter. The isolated microorganism was named Acinetobacter guillouiae Repla2 strain and was deposited on November 10, 2022 at the Korean Agricultural Culture Collection (KACC) of the National Academy of Agricultural Sciences, with the designated deposit number KACC 81234BP.

[0052] Hereinafter, the isolated strain will be referred to as "Repla2".

[0053] Example 2: Verification of plastic degradation ability

[0054] 2-1. Verification of direct plastic metabolism ability

[0055] After culturing for 24 hours in a medium containing a nutrient medium (Luria-Bertani medium, LB), cells corresponding to an absorbance value of 1 at 600 nm (10 9 cells / ml) were collected. The collected Repla2 cells were washed twice with 0.9% saline to remove the previous medium and then suspended in a minimal medium.

[0056] 2,6-Dichlorophenolindophenol (DCPIP), used as an oxidant, and 8 g / L PE (low-density polyethylene, LDPE; Mw approximately 4000, Sigma Aldrich) powder were added to the minimal medium. The Repla2 suspension was inoculated into the resulting medium at a ratio of 1 / 100 (10 7 cells / ml) and cultured, and the DCPIP absorbance was measured every 24 hours. A portion of the medium was collected every 24 hours, and the cells and supernatant were centrifuged, and the absorbance (600 nm) of the supernatant was measured. The DCPIP color change in the experimental group was compared with the following two control groups: 1) a minimal medium inoculated only with Repla2 (without adding LDPE powder); and 2) a minimal medium with only LDPE powder added (without inoculating Repla2).

[0057] When reduced by accepting electrons in the energy generated by microbial metabolic activities, the color of DCPIP changes from blue to colorless. In this way, the direct plastic degradation ability and internal metabolic activity of Repla2 can be indirectly evaluated.

[0058] The results of measuring the absorbance found that in the experimental group with LDPE powder + Repla2 added, as the culture proceeded, the absorbance of the culture solution gradually decreased ( Figure 1)。This result indicates that Repla2 can utilize LDPE powder as the sole carbon source and energy source, and generate reducing energy through internal metabolism. In addition, the absorbance of the culture medium began to decrease significantly approximately one day after the start of the culture, indicating that Repla2 was able to degrade LDPE powder from the start of the culture.

[0059] In Figure 1 , results with statistically significant differences were marked with * when compared with the control group inoculated with only Repla2 in the minimal medium (Mann-Whitney rank sum test, p < 0.05).

[0060] 2-2. Verification of the internal metabolism of plastic monomers

[0061] For microorganisms to metabolize plastics with a polymer structure, the plastics must first be degraded into monomer units with low molecular weight (Mw approximately 500), and then these monomers can be metabolized and utilized by microorganisms in various forms. Among various monomers, hydrocarbon structure substances ([C n H n ) are mainly metabolized through the β-oxidation pathway, and the metabolism must proceed step by step in the order of alkane, alcohol, aldehyde, and fatty acid (references 2 to reference 5). n )

[0062] Therefore, the plastic monomer utilization ability of Repla2 was evaluated.

[0063] In the same manner as in Example 2-1, Repla2 was pre-cultured and then suspended in the minimal medium. Alkanes, alcohols, aldehydes, and fatty acids were added to the minimal medium respectively as the sole energy source and carbon source. The Repla2 suspension was inoculated into the medium at a ratio of 1 / 100 (10 7 cells / ml) for culture, and the DCPIP absorbance was measured every 24 hours. Part of the culture medium was collected every 24 hours, and the cells and the supernatant were separated by centrifugation, and the absorbance of the supernatant (600 nm) was measured. The DCPIP color change of the experimental group was compared with the following two control groups: 1) no energy source and carbon source + addition of Repla2; 2) addition of energy source and carbon source + no addition of Repla2.

[0064] The results of measuring the absorbance found that Repla2 could utilize all of the alkanes, alcohols, aldehydes, and fatty acids used in the experiment as carbon sources, and the metabolic rate was in the order of aldehyde, fatty acid, alkane, alcohol from high to low ( Figure 2 ).

[0065] 2-3. Observation of the growth of Repla2 using plastic film as the carbon source

[0066] The plastic degradation ability of Repla2 was further demonstrated as follows.

[0067] Plastic powder (LDPE) was added to the minimal medium, and Escherichia coli (control group) or Repla2 was inoculated and cultured under aerobic conditions (28 °C, 130 rpm) for approximately 7 days. After 7 days, the culture broth was collected, and the viable cell counts of Escherichia coli and Repla2 were confirmed in terms of colony-forming units (CFU).

[0068] The results confirmed that Escherichia coli in the control group died after 7 days of culture, while Repla2 proliferated in the experimental group inoculated with Repla2 ( Figure 3 ). These results indicated that Escherichia coli in the control group could not utilize plastic powder as a carbon source, while Repla2 could utilize plastic powder as a carbon source.

[0069] Next, to observe the biofilm formation of Repla2, plastic film (LDPE) was added to the minimal medium, inoculated with Repla2, and cultured under aerobic conditions with shaking (28 °C, 130 rpm) for about 7 days. After 7 days, the plastic film was recovered from the medium, and the microbial biofilm formed on the surface of the plastic film and the corrosion caused by biodegradation were observed using a scanning electron microscope. The results showed that after 28 days of culture, the microbial biofilm formation of Repla2 was observed on the plastic surface ( Figure 4 C), and the corrosion of the plastic surface caused by biodegradation was also confirmed ( Figure 4 B). On the other hand, in the control group (without adding Repla2), no microbial biofilm formation or plastic surface corrosion was observed ( Figure 4 A).

[0070] 2-4. Degradation of plastics using Repla2

[0071] The plastic degradation activity of Repla2 was verified by the dry weight measurement method. Plastic powders of various materials were provided as the sole carbon source in the minimal medium, inoculated with Repla2, and cultured under aerobic conditions with shaking (28 °C, 130 rpm) for 7 days. The plastic degradation rate of the strain was calculated according to Mathematical Formula 1.

[0072] [Mathematical Formula 1]

[0073] Plastic degradation rate of Repla2 = (A - B) / A * 100

[0074] (A: Initial plastic weight, B: Residual plastic weight after degradation)

[0075] The calculation results confirmed that after 7 days of culture, 3.18% of PE, 9.07% of PS, 1.29% of PVC, 4.42% of PET, 4.41% of PU, and 0.78% of PP were degraded ( Figure 5 ).

[0076] 2-5. Plastic oxidation using Repla2

[0077] Plastics are hydrophobic materials. In order to biodegrade plastics, a process of hydrophilizing plastics through oxidation must be carried out. Therefore, in this study, plastic films were used as the sole carbon source to verify the plastic oxidation ability of Repla2.

[0078] Plastic films (LDPE) were added to the basal medium, and Repla2 was inoculated and cultured under aerobic conditions with shaking (28 °C, 130 rpm) for about 7 days. After 7 days, the plastic films were recovered from the medium, and X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), and a contact angle meter were used to confirm plastic oxidation.

[0079] The results of XPS analysis confirmed that the oxygen element increased on the plastic surface and carbonyl groups (C=O) were formed (Figures 6A and 6B). The results of FT-IR analysis showed that hydroxyl groups (OH) and carbonyl groups (C=O) were formed on the chemical functional groups on the plastic surface (Figure 6C). In addition, the results of contact angle measurement confirmed that the contact angle of the plastic cultured with Repla2 decreased, proving that the hydrophilicity of the plastic was enhanced (Figure 6D).

[0080] The results shown in Figure 6 confirmed that Repla2 was able to oxidize plastics. Since plastic oxidation can promote plastic degradation, Repla2 can not only degrade plastics by culturing alone or in combination with other strains, but also improve the plastic degradation rate.

[0081] 2-6. Confirmation of degrading plastics using only the enzymes in the Repla2 medium

[0082] After culturing Repla2 with plastics, the microorganisms were removed by filtration to obtain a medium containing enzymes. The presence of enzymes in the medium was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) ( Figure 7 ).

[0083] In addition, the plastic degradation activity of the Repla2 medium was verified by dry weight measurement. Plastic powder (LDPE) was added to the Repla2 medium from which microorganisms had been removed and cultured under aerobic conditions (28 °C, 130 rpm) for about 7 days. The plastic degradation rate of the medium was calculated according to Mathematical formula 1. The plastic degradation rate of the Repla2 medium was calculated by subtracting the value shown in the control group from the value shown in the Repla2 medium.

[0084] The calculation results confirmed that in the Repla2 medium, 1.02% of the plastic powder was degraded after 2 days of culture and 2.17% of the plastic powder was degraded after 7 days of culture ( Figure 8 ).

[0085] [References]

[0086] 1. Stephen M. Jones, Edward I. Solomon. Electron Transfer and Reaction Mechanism of Laccases. Cell Mol Life Sci. 2015 Mar;72(5):869 - 883.

[0087] 2. Zahra Montazer et al. Challenges with Verifying Microbial Degradation of Polyethylene. Polymers (Basel). 2020 Jan;12(1):123.

[0088] 3. Zahra Montazer et al. Microbial degradation of low - density polyethylene and synthesis of polyhydroxyalkanoate polymers. Can J Microbiol. 2019 Mar;65(3):224 - 234.

[0089] 4. Hector M. Alvarez. Relationship between β - oxidation pathway and the hydrocarbon - degrading profile in actinomycetes bacteria. International Biodeterioration & Biodegradation Volume 52, Issue 1, July 2003, Pages 35 - 42.

[0090] 5. Masaji Watanabe et al. Computational method for analysis of polyethylene biodegradation. Journal of Computational and Applied Mathematics Volume 161, Issue 1, 1 December 2003, Pages 133 - 144.

[0091] [Deposit Number]

[0092] Depositor: Rural Development Administration, National Academy of Agricultural Sciences, Korean Agricultural Culture Collection (KACC)

[0093] Accession Number: KACC 81234BP

[0094] Deposit Date: 20221104

[0095]

Claims

1. An Acinetobacter guillouiae Repla2 strain with plastic degradation activity, and its deposit number is KACC 81234BP.

2. The strain according to claim 1, wherein the plastic is one or more selected from the group consisting of polyethylene terephthalate (PET), polyvinyl chloride (PVC), polystyrene (PS), polypropylene (PP), polyurethane (PU), and polyethylene (PE).

3. A method for degrading plastics, comprising the step of culturing plastics with the Acinetobacter guillouiae Repla2 strain with deposit number KACC 81234BP, the strain culture solution, the strain lysate, or the plastic degradation enzyme derived from the strain.

4. The method according to claim 3, wherein the plastic is one or more selected from the group consisting of polyethylene terephthalate (PET), polyvinyl chloride (PVC), polystyrene (PS), polypropylene (PP), polyurethane (PU), and polyethylene (PE).

5. A composition for degrading plastics, comprising the Acinetobacter guillouiae Repla2 strain with deposit number KACC 81234BP, the strain culture solution, the strain lysate, or the plastic degradation enzyme derived from the strain.

6. The composition according to claim 5, wherein the plastic is one or more selected from the group consisting of polyethylene terephthalate (PET), polyvinyl chloride (PVC), polystyrene (PS), polypropylene (PP), polyurethane (PU), and polyethylene (PE).

7. A method for degrading plastic metabolic intermediates, comprising the step of culturing plastic metabolic intermediates with the Acinetobacter guillouiae Repla2 strain with deposit number KACC 81234BP, the strain culture solution, the strain lysate, or the plastic degradation enzyme derived from the strain, wherein the plastic metabolic intermediate is one or more selected from the group consisting of alkanes, alcohols, aldehydes, and fatty acids.

8. A composition for degrading plastic metabolic intermediates, comprising the Acinetobacter guillouiae Repla2 strain with deposit number KACC 81234BP, the strain culture solution, the strain lysate, or the plastic degradation enzyme derived from the strain, wherein the plastic metabolic intermediate is one or more selected from the group consisting of alkanes, alcohols, aldehydes, and fatty acids.

9. A composition for promoting plastic oxidation, comprising the Acinetobacter guillouiae Repla2 strain with deposit number KACC 81234BP, the strain culture solution, the strain lysate, or the plastic degradation enzyme derived from the strain, wherein the plastic is one or more selected from the group consisting of polyethylene terephthalate (PET), polyvinyl chloride (PVC), polystyrene (PS), polypropylene (PP), polyurethane (PU), and polyethylene (PE).

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