Three plastic degradation composite flora and application thereof
By using a composite microbial community of Pseudomonas JM16B3a with Rhodococcus 1.819, Burkholderia cepacia IO2, or Haloxylon ammodendron 6D45AT, the problem of single-species bacteria being unable to efficiently degrade polyester plastics was solved, achieving significant biodegradation effects for PET and PBAT.
Patent Information
- Application Number
- CN202511839190.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-08
- Publication Date
- 2026-01-30
AI Technical Summary
In existing technologies, single bacterial strains are difficult to efficiently degrade complex polyester plastics, and the accumulation of intermediate metabolites may be toxic to the strains, resulting in low degradation efficiency and failing to meet the needs of large-scale applications.
A composite microbial community consisting of Pseudomonas JM16B3a, Rhodococcus 1.819, Burkholderia cepacia IO2, or Haloxylon ammodendron 6D45AT was formed by mixing and culturing in LB liquid medium to form a 1:1 ratio composite microbial community, which was used to degrade polyester plastics such as PET and PBAT.
The composite microbial community significantly improved the degradation efficiency of PET and PBAT plastics, forming biofilms and effectively degrading the plastics, thus enhancing the degradation effect of individual microbial species.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the field of genetic engineering, and particularly relates to three kinds of composite microbial flora and application thereof in biodegradation of polyester plastics. BACKGROUND
[0002] Plastics play an important role in various fields of today's society, however, due to their extremely difficult degradation in the natural environment and continuous accumulation, plastic waste has become a serious threat to the ecological environment and human health. Polyester plastics are widely used in the fields of clothing, food and beverage packaging, and degradation and recycling of their waste are currently a hot issue faced by the world.
[0003] Compared with chemical and physical methods, biocatalytic degradation and recycling of waste plastics have the advantages of mild reaction, green environmental protection, etc., are an "upcycling" process, and are the most promising way of plastic degradation, in which microorganisms and their secreted extracellular enzymes are the core of biocatalysis. In recent years, some microorganisms have been found to have plastic degradation activity, but there are still problems such as low degradation efficiency, which cannot meet the needs of large-scale application. Single species in nature usually cannot completely degrade and utilize complex polymers, and accumulation of intermediate metabolites may be toxic to the species. There may be functional complementation and division of labor among different species, and the metabolic product of one microorganism may be the food of another microorganism, thereby relieving the toxicity of intermediate metabolites and improving the efficiency of plastic degradation. SUMMARY
[0004] The purpose of the present application is to provide three kinds of plastic-degrading composite microbial flora and application thereof in degradation of plastics such as PET and PBAT.
[0005] The composite microbial flora comprises:
[0006] a composite microbial flora of Pseudomonas and Rhodococcus, Burkholderia or Halomonas.
[0007] Preferably, the composite microbial flora comprises
[0008] Composite microbial flora 1, consisting of Pseudomonas JM16B3a GDMCC 805881 and Rhodococcus 1.819 GDMCC 1.819;
[0009] or composite microbial flora 2, consisting of Pseudomonas JM16B3a GDMCC 805881 and Burkholderia IO2 GDMCC 810307;
[0010] or composite microbial flora 3, consisting of Pseudomonas JM16B3a GDMCC 805881 and Halomonas 6D45A TGDMCC 1.1960.
[0011] Further preferably, the quantity ratio of the two bacteria in the complex bacterial flora is 1:1.
[0012] Preferably, the preparation method of the complex bacterial flora is as follows: Pseudomonas JM16B3a, Rhodococcus 1.819, Burkholderia cenocepacia IO2, and Halomonas tianshaniae 6D45AT are inoculated into LB liquid medium respectively, and shaken at 30 DEG C until OD 600 The Pseudomonas JM16B3a is mixed with Rhodococcus 1.819, Burkholderia cenocepacia IO2, and Halomonas tianshaniae 6D45AT respectively at a ratio of 1:1 to obtain three complex bacterial floras respectively.
[0013] The application further provides the application of the three complex bacterial floras in the degradation of polyester plastics.
[0014] Preferably, the polyester plastics are PET and PBAT.
[0015] The application further provides a method for degrading polyester plastics, which is to use the complex bacterial flora to degrade polyester plastics.
[0016] Preferably, the polyester plastics are PET and PBAT.
[0017] Preferably, the polyester plastics are placed in a system containing the complex bacterial flora for degradation.
[0018] The application has the following beneficial effects:
[0019] The three complex bacterial floras have polyester plastic hydrolytic enzyme activity, and have significant degradation effect on PET, PBAT and other polyesters, which shows that the three complex bacterial floras have great application potential and research value in the biodegradation of polyester plastics. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 : Growth of the three complex bacterial floras in MSM medium containing PET plastics;
[0021] Figure 2 : Scanning electron microscope observation of the formation of biofilm of the three complex bacterial floras on the surface of PET plastics;
[0022] Figure 3 : Scanning electron microscope observation of the degradation of PET plastics by the three complex bacterial floras;
[0023] Figure 4 : Growth of the three complex bacterial floras in MSM medium containing PBAT plastics;
[0024] Figure 5 : Scanning electron microscope observation of the formation of biofilm of the three complex bacterial floras on the surface of PBAT plastics;
[0025] Figure 6 SEM observation of the degradation of PBAT plastic by the three composite bacterial communities. DETAILED DESCRIPTION
[0026] The following are specific implementation examples of the present application. It should be noted that these examples are merely exemplary and do not constitute any limitation on the scope of the present application. Modifications and substitutions to the details and forms of the embodiments under the spirit and scope of the present application all fall within the protection scope of the present application.
[0027] Unless defined, the technical terms used in the following examples have the same meaning as generally understood by those skilled in the art to which the present application belongs. The experimental reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the experimental methods, unless otherwise specified, are all conventional methods.
[0028] Unless otherwise specified, JM16B3a mentioned in the following examples is Pseudomonas JM16B3a (Accession No. GDMCC 805881), 1.819 is Rhodococcus 1.819 (Accession No. GDMCC 1.819), IO2 is Burkholderia IO2 (Accession No. GDMCC 810307), and 6D45AT is Halomonas mangrovensis 6D45AT (Accession No. GDMCC 1.1960). These strains are preserved in the Guangdong Microbial Culture Collection Center (GDMCC), and those skilled in the art can purchase them.
[0029] Example 1: Preparation of three composite bacterial communities
[0030] The glycerol bacteria of JM16B3a, 1.819, IO2, and 6D45AT stored in the freezer were respectively streaked on LB plates (NaCl 10 g / L, tryptone 10 g / L, yeast extract 5 g / L, agar 15 g / L) and cultured in a 30°C incubator until single colonies grew. Single colonies were respectively picked into LB liquid medium (NaCl 10 g / L, tryptone 10 g / L, yeast extract 5 g / L) and cultured in a 30°C shaker at 180 rpm until the OD 600 was 0.6-0.8, i.e. the logarithmic growth phase. The logarithmic growth phase JM16B3a bacterial solution was inoculated with the 1.819 bacterial solution at a volume ratio of 1:1, i.e. composite bacterial community 1. The logarithmic growth phase JM16B3a bacterial solution was inoculated with the IO2 bacterial solution at a volume ratio of 1:1, i.e. composite bacterial community 2. The logarithmic growth phase JM16B3a bacterial solution was inoculated with the 6D45AT bacterial solution at a volume ratio of 1:1, i.e. composite bacterial community 3.
[0031] Example 2: Application of three composite bacterial communities in PET degradation
[0032] PET film was purchased from Guangzhou Huayu Trading Co., Ltd. The PET film was cut into 2cm x 2cm pieces, soaked in 2% SDS overnight, rinsed 5 times with sterile water, soaked in 75% ethanol for 4 hours, washed 5 times with sterile water under sterile conditions, air-dried in a laminar flow hood, and sterilized by ultraviolet irradiation for 30 minutes.
[0033] The processed PET tablets were added to basal salt liquid medium (MSM medium, purchased from Cooler Master), with 6 tablets inoculated into each shake flask. A compound bacterial culture was inoculated at a 2% (v / v) ratio, i.e., JM16B3a bacterial suspension was mixed with 1.819, IO2, or 6D45AT bacterial suspension at a 1%:1% (v / v) ratio into the basal salt liquid medium. The cultures were incubated at 30°C with shaking at 180 rpm. Samples were taken at regular intervals to detect the OD of the bacterial suspension. 600 The single-strain control group was inoculated with JM16B3a, 1.819, IO2, or 6D45AT at the same inoculation ratio. The blank control group was not inoculated with a complex bacterial culture. Each group had three replicates. Figure 1 As shown, all three bacterial complexes were able to grow in MSM liquid medium containing PET sheets.
[0034] After 60 days of incubation, the plastic slides were removed. Three of them were rinsed three times with sterile water, air-dried, and the growth of bacterial biofilm on the surface of the plastic slides was observed using a scanning electron microscope. The results are as follows: Figure 2 As shown, both JM16B3a alone and the three combined bacterial groups can attach and grow on the PET surface to form biofilms. Individually inoculated 1.819, IO2, or 6D45AT are similar to individually inoculated JM16B3a in forming biofilms on the PET surface.
[0035] The other three plastic sheets were immersed in 2% SDS and ultrasonically cleaned to remove the biofilm growing on the surface. They were then washed five times with sterile water, dried, and the degradation of the plastic was observed using a scanning electron microscope. The results are as follows: Figure 3 As shown, compared with the control group, JM16B3a alone can cause corrosion on the PET plastic surface, while all three composite bacterial groups can significantly degrade PET plastic, with the degradation effect being significantly enhanced compared to JM16B3a alone. Individual inoculation with 1.819, IO2, or 6D45AT did not show significant degradation on the PET surface.
[0036] Example 3: Application of three complex microbial communities in PBAT degradation
[0037] PBAT refers to used biodegradable plastic bags purchased from Hema Fresh. The PBAT plastic bags were cut into 2cm x 2cm pieces, and the pretreatment, UV sterilization, inoculation, and incubation methods were the same as described in Example 2.
[0038] The results are as follows Figure 4As shown, both JM16B3a alone and the three combined bacterial groups were able to grow in MSM liquid medium containing PBAT sheets; scanning electron microscopy results showed that JM16B3a alone and the three combined bacterial groups were able to attach to and grow on the PBAT plastic surface to form a biofilm. Figure 5 The three types of compound bacteria can significantly degrade PBAT plastic. Figure 6 Individually inoculated 1.819, IO2, or 6D45AT can form biofilms on the PBAT surface, but no significant degradation is observed.
Claims
1. A plastic-degrading consortium of bacteria, characterized in that, The complex bacterial flora comprises a complex bacterial flora of Pseudomonas and Rhodococcus, Burkholderia cenocepacia or Halomonas uda.
2. The consortium of claim 1, wherein, The complex bacterial flora comprises: Complex bacterial flora 1, consisting of Pseudomonas JM16B3a GDMCC 805881 and Rhodococcus 1.819 GDMCC 1.819; or complex bacterial flora 2, consisting of Pseudomonas JM16B3a GDMCC 805881 and Burkholderia cenocepacia IO2 GDMCC 810307; or complex bacterial flora 3, consisting of Pseudomonas JM16B3a GDMCC 805881 and Halomonas uda 6D45AT GDMCC 1.1960.
3. The consortium of claim 1, wherein, The quantity ratio of the two bacteria in the complex bacterial flora is 1:
1.
4. The consortium of claim 1, wherein, The preparation method of the complex bacterial flora is as follows: Pseudomonas JM16B3a, Rhodococcus 1.819, Burkholderia cenocepacia IO2 and Halomonas tianshuiensis 6D45AT are respectively inoculated into LB liquid medium, and shaken at 30 DEG C until OD 600 <6000000> Pseudomonas JM16B3a is mixed with Rhodococcus 1.819, Burkholderia cenocepacia IO2 and Halomonas tianshuiensis 6D45AT in a ratio of 1:1 to obtain three kinds of complex bacterial flora respectively.
5. Use of the complex bacterial flora of claim 1, 2, 3 or 4 in the degradation of polyester plastics.
6. Use according to claim 5, characterized in that, The polyester plastics are PET or PBAT.
7. A method of degrading a polyester plastic, characterized by, It is to use the complex bacterial flora of claim 1, 2, 3 or 4 to degrade polyester plastics.
8. The method of claim 7, wherein, The polyester plastics are PET or PBAT.
9. The method according to claim 7 or 8, characterized in that, It is to place the polyester plastics in a system containing the complex bacterial flora for degradation. The polyester plastics are PET or PBAT.