Aspergillus cephalosporans PM-b capable of efficiently degrading poly (butylene adipate-co-terephthalate) and application of aspergillus cephalosporans PM-b

Abstract

The invention discloses aspergillus cephalosporium PM-b capable of efficiently degrading poly (butylene adipate-co-terephthalate) (PBAT) and application of the aspergillus cephalosporium PM-b. The aspergillus cephalosporium PM-b screened from anaerobic activated sludge can effectively degrade a PBAT film in a short time, and when the temperature is 35 DEG C, the pH value is 7.6, and the inoculation amount of a seed solution is 0.1% of the volume of an inorganic salt culture medium, the PBAT film can be effectively degraded in a short time. Under the condition that the volume inoculation amount of an external carbon source is 3.3%, the degradation rate of the PBAT film within 30 days can reach 5.6%. The aspergillus cephalosporium PM-b is facultative anaerobic bacteria and can degrade PBAT in a low-oxygen environment, the degradation behavior in the low-oxygen environment has better carbon sequestration capacity compared with that in a normal environment, strain support is provided for low-carbon treatment of PBAT, and a theoretical basis is provided for research of a degradation mechanism of the aspergillus cephalosporium PM-b.

Description

(1) Technical field

[0001] The invention belongs to the technical field of microorganisms and relates to a strain of Aspergillus cephalosporin PM-b capable of efficiently degrading poly(butylene terephthalate-adipate) and application thereof. (2) Background technology

[0002] Polybutylene terephthalate-adipate (PBAT) is a major player in the biodegradable plastics industry, accounting for 23% of global biodegradable plastics production capacity in 2020. PBAT is a highly biodegradable polymer primarily used in plastic packaging, such as shopping bags and garbage bags, but also in tableware and mulch. According to statistics, over 60% of PBAT products will be plastic films in 2023. The continued use of biodegradable plastics like PBAT is significant. According to statistics, the production capacity of biodegradable plastics reached 2.217 million tons in 2022, with total PBAT production capacity reaching 199,500 tons / year, accounting for 9% of global biodegradable plastics production capacity.

[0003] As a biodegradable material, PBAT generally has deficiencies in hydrolysis resistance and water vapor barrier properties. To enhance the durability of PBAT products, plastic additives, such as polycarbodiimide, are often added during the research and development process. While these additives improve PBAT's performance, they also increase the difficulty of degradation. Under normal circumstances, PBAT's natural degradation requires more than six months, or even longer. Related studies have also shown that PBAT's natural degradation efficiency is not high in the short term, with degradation primarily occurring after 90 days. Accelerating PBAT degradation often requires specific environmental conditions, such as medium-high temperatures and alkalinity. However, these physical and chemical methods are economically prohibitive in practical applications and are difficult to promote. Biodegradation, by comparison, has become a more economical option.

[0004] Current research on PBAT film degradation primarily focuses on bacteria. Pseudomonas knackmussii can degrade PBAT by 6.5% within 56 days, Klebsiella pneumoniae N3-2 can degrade PBAT by 6.53% within 56 days, Bacillus pumilus can degrade PBAT by 1.2% within 10 days, and Sphingopyxis ginsengisoli can degrade PBAT by 0.92% within 60 days. To increase degradation rates, specialized degradation environments are required. For example, Oligotrophomonas degrades PBAT by over 10% in an alkaline environment within 5 days, while Thermomonospora fusca degrades 99.9% after 22 days of cultivation at 55°C. These specialized degradation environments require additional provision, making them inefficient and cost-effective in practical applications.

[0005] Therefore, screening out strains that can effectively degrade PBAT in a short period of time is of great significance for the subsequent biodegradation of PBAT, both in terms of application and mechanism research. (3) Summary of the invention

[0006] The purpose of the present invention is to provide a facultative anaerobic fungus, Aspergillus cephalosporin PM-b, which can efficiently degrade PBAT and its application. The strain can efficiently degrade PBAT in a short period of time.

[0007] The technical solution adopted in the present invention is:

[0008] The present invention provides a new strain capable of efficiently degrading PBAT - Aspergillus cejpii PM-b, which is deposited in the China Center for Type Culture Collection with a deposit number of CCTCC NO: M 20242619 and a deposit date of November 21, 2024. The address is: Wuhan University, Wuhan, China, 430072.

[0009] The cephalosporin PM-b of the present invention is screened from anaerobic activated sludge samples, and has the following mycelial characteristics: the mycelium is white and has a dry and hydrophobic surface.

[0010] The present invention also provides an application of the Cephalosporin PM-b in degrading PBAT.

[0011] Furthermore, the application method is: inoculating Cephalosporin PM-b into an inorganic salt culture medium containing PBAT, and culturing at 25-35°C and 100-200 rpm (preferably 35°C and 180 rpm) to achieve efficient degradation of PBAT.

[0012] Furthermore, the concentration of PBAT in the inorganic salt culture medium is 0.1-1 g / L (preferably 40-60 mg / 150 mL), and the inoculation amount of Cephalosporin PM-b is 1.0×10 2 ~1.0×10 5 CFU / mL.

[0013] Furthermore, the inorganic salt culture medium is composed of: (NH4)2SO4 1.0g·L -1 、MgSO4·7H2O 0.2g·L -1 、K2HPO4 1.6g·L -1 、NaCl 0.1g·L -1 、CaCl2·2H2O 0.02g·L -1 、FeSO4·7H2O 0.01g·L -1 , solvent is water, natural pH (7.2-7.6).

[0014] Furthermore, before inoculating the inorganic salt culture medium, the cephalosporin PM-b is first inoculated into a solid red bengal culture medium for activation culture, the spores are collected with physiological saline and resuspended to obtain a seed liquid, the seed liquid is then inoculated into a liquid red bengal culture medium for adaptive culture, and finally the entire bacterial liquid after the adaptive culture is inoculated into an inorganic salt culture medium containing PBAT.

[0015] Furthermore, in the inorganic salt medium, the inoculation amount of the entire bacterial solution is calculated based on the seed solution and the liquid red bengal medium, wherein the seed solution inoculation amount is 0.1-0.4% (preferably 0.1%) by volume, and the spore concentration is 1.0×10 2 ~1.0×10 5 CFU / mL; the volume inoculation amount of liquid tiger red medium as an external carbon source is 0.6-7%.

[0016] Furthermore, the activation culture conditions were 30° C. activation culture for 72 h; and the adaptive culture conditions were 30° C., 180 rpm shaking incubator culture for 24 h.

[0017] Furthermore, the application method is as follows: a glycerol stock solution of Cephalosporin PM-b stored at -80°C is diluted with sterile physiological saline and then applied to a solid red bengal culture medium, cultured at a constant temperature of 30°C until the surface of the culture medium is covered with colonies, sterile physiological saline is added dropwise to cover the colonies, the colonies are gently scraped with an inoculating loop to release them into the physiological saline, and the physiological saline containing bacteria is transferred to a centrifuge tube, centrifuged at 2500 rpm, the supernatant and residual culture medium fragments are discarded, and the bacterial precipitate is resuspended with new sterile physiological saline (preferably to a bacterial concentration of 1.0×10 5 ~1.0×10 7 CFU / mL) to obtain a seed solution; the seed solution was inoculated into a liquid red bengal culture medium at a volume concentration of 3%, and cultured in a shaking incubator at 30°C and 180 rpm for 24 hours to enhance the adaptability of the strain; the bacterial solution after all the adaptability culture was inoculated into an inorganic salt culture medium containing PBAT, and cultured at 35°C and 180 rpm to achieve efficient degradation of PBAT.

[0018] The liquid red bengal medium: peptone 5.0g·L -1 , glucose 10.0 g·L -1 、KH2PO4 1.0g·L -1 、MgSO4·7H2O 0.5g·L -1 The solvent is water, and the pH is 7.2. The solid bengal culture medium is prepared by adding 10 g / L agar to the liquid bengal culture medium.

[0019] Compared with the prior art, the beneficial effects of the present invention are mainly reflected in:

[0020] The cephalosporin PM-b strain screened from anaerobic activated sludge in the present invention can effectively degrade PBAT film in a short period of time. Under the conditions of 35°C, pH 7.6, a seed liquid inoculation amount of 0.1% of the volume of the inorganic salt culture medium, and an external carbon source inoculation amount of 3.3%, the degradation rate of the PBAT film can reach 5.6% within 30 days.

[0021] The cephalosporin PM-b of the present invention is a facultative anaerobic bacterium that can also degrade PBAT in a low-oxygen environment. The degradation behavior in a low-oxygen environment has better carbon fixation ability than that in a normal environment, providing strain support for low-carbon treatment of PBAT and providing a theoretical basis for the study of its degradation mechanism. (IV) Description of the accompanying drawings

[0022] Figure 1 , Comparison of PBAT degradation rates by different strains.

[0023] Figure 2 , plate streak diagram of strain PM-b.

[0024] Figure 3 , developmental tree of strain PM-b.

[0025] Figure 4 , Bar chart of the degradation rate of strain PM-b under different conditions. (V) Specific implementation methods

[0026] The present invention is further described below with reference to specific embodiments, but the protection scope of the present invention is not limited thereto:

[0027] The culture medium involved in the embodiment of the present invention comprises:

[0028] Trace carbon source liquid culture medium: yeast extract 0.5 g·L -1 、(NH4)2SO4 2.0g·L -1 , trace element mother solution 100mL·L -1 The solvent is water, pH 7.0; the trace element mother solution: FeSO4·7H2O 1.0g·L -1 、MgSO4·7H2O1.0g·L -1 、CuSO4·5H2O 0.1g·L -1 、MnSO4·H2O 0.1g·L -1 、ZnSO4·7H2O 0.1g·L -1 , the solvent is water.

[0029] Inorganic salt culture medium: (NH4)2SO4 1.0g·L -1 、MgSO4·7H2O 0.2g·L -1、K2HPO4 1.6g·L -1 、NaCl 0.1g·L -1 、CaCl2·2H2O 0.02g·L -1 、FeSO4·7H2O 0.01g·L -1 , solvent is water, pH 8.0.

[0030] Liquid LB medium: peptone 10.0 g·L -1 , yeast extract 5.0g·L -1 、NaCl 10.0g·L -1 , solvent is water, pH 7.3.

[0031] Solid LB medium: peptone 10.0 g·L -1 , yeast extract 5.0g·L -1 、NaCl 10.0g·L -1 , agar 10 g·L -1 , solvent is water, pH 7.0.

[0032] Liquid red bengal medium: peptone 5.0 g·L -1 , glucose 10.0 g·L -1 、KH2PO4 1.0g·L -1 、MgSO4·7H2O 0.5g·L -1 , solvent is water, pH 7.2.

[0033] Solid red bengal medium: peptone 5.0 g·L -1 , glucose 10.0 g·L -1 、KH2PO4 1.0g·L -1 、MgSO4·7H2O 0.5g·L -1 , agar 10 g·L -1 , solvent is water, pH 7.3.

[0034] All culture media were sterilized in an autoclave at 121°C for 30 min before use.

[0035] Main reagents and instruments of the embodiment of the present invention:

[0036] 80-mesh PBAT powder, sodium dodecyl sulfate (SDS), glycerol, 75% ethanol, 95% ethanol, dichloromethane, high-pressure steam sterilizer (Shidukai Instrument Equipment Co., Ltd.), constant temperature shaking incubator (Shanghai Yiheng Scientific Instrument Co., Ltd.), anaerobic glove box, drying oven, micrometer balance.

[0037] Example 1: Isolation and purification of PBAT-degrading bacteria

[0038] 1. Preparation of PBAT film

[0039] Take 5g of 80-mesh PBAT powder, add 50mL of dichloromethane, and sonicate at 400W for 1h to fully dissolve it. Pipette 3mL of the PBAT solution into a 9cm diameter circular Teflon mold and shake to evenly distribute the solution throughout the mold. Place the mold in a fume hood and wait until the dichloromethane evaporates completely before removing it for later use. Unless otherwise specified, the PBAT film prepared in this manner is referred to herein as a PBAT film with a thickness of approximately 0.5mm.

[0040] 2. Pretreatment of PBAT film

[0041] The PBAT film prepared in step 1 was immersed in a 2% SDS aqueous solution (2g of SDS powder in 100mL of water). Ultrasonication was performed at 400W for 0.5h, vortexing was performed for 0.5h, and the film was allowed to stand for at least 3h. After the film was rinsed with ultrapure water, 95% ethanol was added, and the sonication, vortexing, and standing process was repeated. After the film was rinsed with ultrapure water, 75% ethanol was added, and the sonication, vortexing, and standing process was repeated. After the process was completed, the film was removed and dried with sterile filter paper. It was then placed in an oven at 45°C for at least 24h. The resulting PBAT film was the pretreated PBAT film. Each 9cm diameter PBAT film was divided into four equal parts, with each sector weighing 40-60mg, and set aside. The PBAT film was cleaned as described above after the incubation.

[0042] 3. Enrichment culture

[0043] 10 mL of anaerobic sludge sample taken from a sewage treatment plant in Deqing County, Huzhou City, Zhejiang Province was added to 100 mL of trace carbon source liquid culture medium, and 1 fan-shaped PBAT film prepared in step 2 was added. The culture was cultured in a constant temperature shaker at 30°C and 180 rpm for 30 days. During the culture period, part of the culture medium was updated every 10 days, and the replacement amount was 20% of the old culture medium volume, that is, 20 mL of culture medium was aspirated with a pipette, and 20 mL of fresh culture medium was added.

[0044] 4. Separation and purification

[0045] The culture fluid obtained after 30 days of enrichment culture in step 3 was diluted with physiological saline for 10 -2 , 10 -3 , 10 -4 times, take 0.1 mL and spread it on solid LB medium and solid red bengal medium respectively. After colonies grow, pick colonies with obvious morphological differences and perform four-zone streaking. The streaking operation can be performed multiple times according to the actual situation until a single colony is obtained. The single colony obtained by streaking is preserved in 30% glycerol aqueous solution and stored at -80℃ for later use.

[0046] After this separation and purification, 3 bacterial strains and 4 fungal strains were obtained, which were named strain PX-1, strain PX-3, strain PX-4, strain PM-b, strain PM-h, strain PM-lv, and strain PM-ho respectively.

[0047] Example 2: Screening of PBAT-degrading bacteria

[0048] 1. Bacteria screening

[0049] The glycerol stock of strains PX-1, PX-3, and PX-4 frozen in Example 1 was thawed at room temperature, and then four zones were drawn on solid LB medium and cultured in a constant temperature incubator at 30°C until the colonies grew stably on the surface of the medium.

[0050] Use an inoculation loop to pick a certain amount of PX-1, PX-3, and PX-4 colonies into 5 mL of liquid LB medium. After culturing in a shaking incubator at 30°C and 180 rpm for 24 hours, the resulting bacterial solution was centrifuged in an 8000 rpm high-speed centrifuge for 5 minutes, the upper culture medium was discarded, the bacteria were washed 3 times with sterile water and resuspended, and the OD600 of the 5 mL resuspended solution was adjusted to 0.8. Then, the 5 mL resuspended solution was transferred to 150 mL of inorganic salt culture medium, and a fan-shaped PBAT film prepared in Example 1 was added. The solution was cultured at 30°C and 180 rpm for 30 days. A sterile blank group was added, and 3 parallels were made for each group. After 30 days, the film was washed and dried, and the mass was measured with a microbalance. The degradation rate was calculated. Figure 1 .

[0051]

[0052] m0 is the mass of PBAT film before culture;

[0053] m1 is the mass of PBAT film after incubation.

[0054] 2. Screening of fungi

[0055] The glycerol stock solutions of the fungi PM-b, PM-h, PM-lv and PM-ho stored at -80°C were thawed at room temperature and diluted 10% with sterile saline. -2 , 10 -3 , 10 -4After that, 0.1 mL was spread on solid red bengal culture medium, activated and cultured at 30°C for 72 h, and the number of colonies was counted. The concentration of the diluted bacterial solution was marked and set aside. 0.1 mL of diluted bacterial solution of different concentrations was spread on solid red bengal culture medium, and cultured at 30°C for several days until the surface of the culture medium was covered with colonies. Sterile physiological saline was added dropwise to the culture dish to cover the fungal colonies. The colonies were gently scraped with an inoculating loop to release them into the physiological saline. The liquid was then transferred to a 10 mL centrifuge tube and centrifuged at 2500 rpm. The supernatant and residual culture medium fragments were discarded, and the bacterial precipitate was resuspended with new sterile physiological saline to obtain a bacterial suspension. The concentration of the bacterial suspension was then adjusted according to the concentration of the diluted bacterial solution to make the bacterial concentration of 1.0 × 10 5 ~1.0×

[0056] 10 7 CFU / mL, to obtain seed liquid; inoculate 0.15mL of seed liquid into 5mL of liquid red bengal culture medium, and carry out adaptive culture in a shaking incubator at 30℃ and 180rpm for 24h. Transfer all the obtained bacterial liquid into 150mL of inorganic salt culture medium, add 1 fan-shaped PBAT film prepared in Example 1, and culture at 30℃ and 180rpm for 30d. A sterile blank group was added, and 3 parallels were made for each group. After 30d, the film was washed and dried, and the mass was measured with a ten-thousandth balance. The degradation rate was calculated. Figure 1 .

[0057] from Figure 1 It can be seen that strain PM-b has the greatest degradation ability, with a degradation rate of 3.04%.

[0058] Example 3, Identification of strain PM-b

[0059] 1. Colony characteristics

[0060] The strain PM-b was inoculated onto solid red tiger culture medium and cultured at 30°C until the culture dish was covered with hyphae, which were white in color and had a dry and hydrophobic surface. Figure 2 shown.

[0061] 2. 16S rDNA sequence analysis

[0062] The PM-b strain genomic DNA was obtained using a boiling method. Specifically, approximately 20 mg of PM-b mycelium grown on solid Bengal rose medium was scraped with a sterile knife in a clean bench. The culture was then ground in liquid nitrogen to obtain the cells. 1 mL of sterile water was added, the tube was labeled, and the cap was tightly closed. The tube was boiled at 95°C for 10 minutes and immediately frozen at -20°C for 5 minutes. This process was repeated three times. The tube was centrifuged at 12,000 rpm for 5 minutes. 1 μL of the supernatant was then used as the DNA template for PCR amplification. PCR amplification was performed using universal primers for molds, ITS1 and ITS4.

[0063] ITS1: 5'-TCCGTAGGTGAACCTGCGG-3'

[0064] ITS4:5'-TCCTCCGCTTATTGATATG-3'

[0065] The amplification system was as follows: 1 μL template, 20 μL premix 2× Taq PCR Master Mix, 3 μL dNTPs, 2 μL each of fungus universal primers, and double-distilled water (ddH2O) was added to 50 μL.

[0066] Amplification conditions: pre-denaturation at 94°C for 5 min; denaturation at 94°C for 30 s, annealing at 54°C for 30 s, and extension at 72°C for 5 min, for 30 cycles.

[0067] The amplified product was sent to Zhejiang Youkang Biotechnology Co., Ltd. for biological sequencing identification, and its 16S rDNA base sequence is shown in SEQ ID NO: 1.

[0068] .

[0069] The results were submitted to the NCBI database for Blast comparison and a developmental tree was constructed ( Figure 3 ).

[0070] After identification, strain PM-b belonged to Aspergillus cejpii, so it was named Aspergillus cejpii PM-b (Aspergillus cejpii) and deposited in the China Center for Type Culture Collection with the deposit number CCTCCNO: M 20242619, the deposit date was November 21, 2024, and the address was: Wuhan University, Wuhan, China, 430072.

[0071] Example 4: Optimization of conditions for PBAT degradation by strain PM-b

[0072] 1. Temperature optimization

[0073] The strain PM-b was inoculated onto solid red tiger medium and cultured at 30°C until the surface of the medium was covered with spores. The medium was washed with sterile saline and centrifuged at 2500 rpm. The supernatant and residual culture medium fragments were discarded. The precipitate was resuspended in new sterile saline and the spore concentration was adjusted to 1.0×10 6 CFU / mL, and obtain seed liquid. Take 0.15mL seed liquid to 5mL liquid bengal red culture medium, and culture in a shaking incubator at 30℃ and 180rpm for 24h to enhance the adaptability of the strain. Transfer all the above-mentioned adapted cultured bacterial liquid to 150mL inorganic salt culture medium, add 1 piece of PBAT film prepared in Example 1, wherein the amount of adapted cultured bacterial liquid added to the inorganic salt culture medium is 0.1% based on the seed liquid volume inoculation amount, and 1.5×10 4 CFU / mL, with an external carbon source (liquid bengal culture medium) added at a volumetric rate of 3.3%. Three parallel groups were cultured in a constant temperature shaker at 25°C, 30°C, and 35°C at 180 rpm for 30 days. The degradation rate was calculated using the method in Example 2. Within the same temperature group, 150 mL of inorganic salt culture medium plus 5 mL of liquid bengal culture medium was used as a blank control.

[0074] 2. Optimization of pH:

[0075] Set the temperature in step 1 to 30°C, and adjust the pH of the inorganic salt medium to 6, 7, 8, and 9, respectively. Other operations are the same as in step 1. In the same pH group, use 150 mL of inorganic salt medium + 5 mL of liquid bengal culture medium as a blank control.

[0076] 3. Optimization of seed solution inoculation amount:

[0077] The temperature of step 1 was set to 30°C, and four seed solution inoculation groups were set, specifically 0.15, 0.3, 0.45, and 0.6 mL. The seed solution inoculation volume was 0.1%-0.4% based on the volume of the inorganic salt culture medium, and the spore volume was 1.5×10 4 CFU, 3.0×10 4 CFU, 4.5×10 4 CFU, 6.0×10 4 CFU, other operations are the same as step 1. Under the same bacterial load conditions, 150 mL inorganic salt medium + 5 mL liquid red bengal medium was used as a blank control.

[0078] 4. Optimization of the amount of added carbon source:

[0079] Set the temperature in step 1 to 30°C. When performing adaptive culture, set up four liquid bengal culture medium groups, that is, transfer 0.15 mL of seed liquid to 1 mL, 3 mL, 5 mL, and 10 mL of liquid bengal culture medium, respectively. Other operations are the same as step 1.

[0080] The entire bacterial suspension from each adaptive culture was inoculated into 150 mL of inorganic salt medium. The volumetric addition of an external carbon source (liquid bengal culture medium) was 0.6% (1 mL), 2% (3 mL), 3.3% (5 mL), and 6.7% (10 mL), respectively. The volumetric addition of seed solution was 0.1%. Blank controls were prepared using 150 mL of inorganic salt medium plus 1, 3, 5, and 10 mL of liquid bengal culture medium.

[0081] See the results Figure 4 , the conclusion is as follows:

[0082] (1) Among the three temperatures, PBAT film showed the highest degradation rate at 35°C, with a net degradation rate of up to 5.6%.

[0083] (2) There was no significant difference in degradation rate under the four pH conditions. In contrast, the net degradation rate was higher at pH 8, reaching 2.84%.

[0084] (3) Among the four seed liquid inoculum sizes, the inoculum sizes of 0.1% and 0.2% had similar degradation rates, both significantly higher than the degradation rates of 0.3% and 0.4%. Among the inoculum sizes of 0.1% and 0.2%, the degradation rate of 0.1% was slightly higher than that of 0.2%, and the net degradation rate could reach 4.8%.

[0085] (4) Among the four amounts of added carbon sources, the degradation rate of the group with an addition amount of 5 ml, that is, an addition amount of 3.3% of the volume concentration, was significantly higher than that of the other three groups, with a net degradation rate of 2.89%.

[0086] In the above experimental categories, the spore inoculum concentration was 1.5×10 4 CFU / mL and the volume inoculation amount of the added carbon source was 3.3%, the strain PM-b had the maximum net degradation rate of 5.6%. Compared with the degradation rate of 3.04% before optimization, the degradation rate after optimization increased by about 1 times.

[0087] In summary, the fungus Aspergillus PM-b isolated and screened by the present invention can be used as a PBAT-degrading bacterium. Compared with the current focus on bacteria for the degradation of PBAT, the Aspergillus PM-b screened by the present invention as a fungus that can degrade PBAT provides the possibility of expanding the research scope.

[0088] The above-described embodiments are only preferred embodiments of the present invention and are not exhaustive of all feasible implementations of the present invention. For those skilled in the art, any obvious modifications made thereto without departing from the principles and spirit of the present invention should be considered to be included within the scope of protection of the claims of the present invention.

Claims

1. Aspergillus cejpii PM-b, deposited with China Center for Type Culture Collection, CCTCC NO: M 20242619, deposit date: November 21, 2024, Address: Wuhan University, Wuhan 430072, China.

2. Use of the Aspergillus cephalosporin PM-b according to claim 1 in degrading polybutylene terephthalate-adipate.

3. The use according to claim 2, characterized in that The application method comprises the following steps: inoculating Aspergillus cephalosporin PM-b into an inorganic salt culture medium containing polybutylene terephthalate-adipate, and culturing the culture medium at 25-35° C. and 100-200 rpm to achieve efficient degradation of the polybutylene terephthalate-adipate.

4. The use according to claim 3, characterized in that The concentration of polybutylene terephthalate-adipate in the inorganic salt culture medium is 0.1-1 g / L, and the inoculation amount of Cephalosporin PM-b is 1.0×10 2 ~1.0×10 5 CFU / mL.

5. The use according to claim 3, characterized in that The inorganic salt culture medium composition: (NH4)2SO4 1.0g·L -1 、MgSO4·7H2O 0.2g·L -1 、K2HPO4 1.6g·L -1 、NaCl 0.1g·L -1 、CaCl2·2H2O 0.02g·L -1 、FeSO4·7H2O0.01g·L -1 , solvent is water, natural pH.

6. The use according to claim 3, characterized in that Before inoculating the inorganic salt culture medium, the cephalosporin PM-b is first inoculated into a solid rose bengal culture medium for activation culture, spores are collected with physiological saline and resuspended to obtain a seed liquid, the seed liquid is then inoculated into a liquid rose bengal culture medium for adaptive culture, and finally the entire bacterial liquid after the adaptive culture is inoculated into an inorganic salt culture medium containing polybutylene terephthalate-adipate.

7. The use according to claim 6, characterized in that In the inorganic salt culture medium, the inoculum volume of all bacterial liquids was calculated based on the seed liquid and liquid red bengal culture medium, and the inoculum volume of the seed liquid was calculated based on the spore concentration of 1.0×10 2 ~1.0×10 5 CFU / mL; the amount of liquid red bengal culture medium added is 0.6-7%.

8. The use according to claim 6, characterized in that The activation culture conditions were 30° C. for 72 h; the adaptive culture conditions were 30° C., 180 rpm shaking incubator for 24 h.

9. The use according to claim 3, characterized in that The application method comprises the following steps: diluting a glycerol preservation solution of Cephalosporin PM-b stored at -80°C with sterile physiological saline and applying the solution to a solid red bengal culture medium; culturing the solution at a constant temperature of 30°C until the surface of the culture medium is covered with colonies; dripping sterile physiological saline to cover the colonies; lightly scraping the colonies with an inoculating loop to release them into the physiological saline; centrifuging the solution; discarding the supernatant and residual culture medium fragments; and resuspending the bacterial precipitate with new sterile physiological saline to obtain a seed solution; inoculating the seed solution into a liquid red bengal culture medium at an inoculum concentration of 3% by volume, and culturing the solution in a shaking incubator at 30°C and 180 rpm for 24 hours to enhance the adaptability of the strain; and inoculating the bacterial solution after all the adaptability cultures into an inorganic salt culture medium containing polybutylene terephthalate-adipate, and culturing the solution at 35°C and 180 rpm to achieve efficient degradation of the polybutylene terephthalate-adipate.

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