Bacillus paramushroom and application thereof in treatment of wastewater containing resistance

Abstract

The invention belongs to the technical field of environmental microorganisms and sewage treatment, and particularly relates to bacillus parabarisiformis and application of the bacillus parabarisiformis in anti-wastewater treatment. The bacillus paramycoides (BCTC-2) is preserved in the China General Microbiological Culture Collection Center (CGMCC), the preservation number is CGMCC No.35352, and the preservation date is July 23, 2025, and the preservation number is CGMCC No.35352. The bacillus paramycoides (BCTC-2) has the advantages that the bacillus paramycoides (BCTC-2) is preserved in the China General Microbiological Culture Collection Center (CGMCC), the preservation number is CGMCC No.35352; the strain can be used for actual antibiotic-containing wastewater treatment, can reduce environmental pollution caused by antibiotic residues, provides a theoretical basis for industrial application of aureomycin efficient degrading bacteria, is beneficial to enriching a strain resource library of the aureomycin degrading bacteria, and provides an effective biodegradation method for pollution treatment of antibiotics in the environment.

Description

A type of *Pseudomonas parasiticus* and its application in the treatment of wastewater containing antibiotics. Technical Field

[0001] This invention belongs to the field of environmental microbiology and wastewater treatment technology, specifically relating to a type of *Pseudomonas aeruginosa* and its application in the treatment of wastewater containing antibiotics. Background Technology

[0002] Tetracycline antibiotics (TCs), the second largest class of antibiotics globally, are among the main drugs used for the treatment of humans and animals. Among them, chlortetracycline (CTC) is widely used in clinical medicine, animal husbandry, and aquaculture due to its good bactericidal effect, low price, and good oral efficacy. It can also be used to treat animal diseases and as a growth promoter added to agricultural feed.

[0003] With the widespread use of antibiotics, their presence and pollution in the environment have become increasingly prominent, particularly their frequent detection in aquatic environments. Currently, they mainly enter the aquatic environment through discharges of livestock and poultry wastewater, medical wastewater, and sewage treatment plant effluent. Antibiotics are chemically stable in aquatic environments, are not easily degraded naturally, and can persist for extended periods, causing persistent harm to the environment and organisms. Antibiotic residues in aquatic environments can damage ecosystems and alter the biological community structure of aquatic ecosystems; furthermore, they can lead to environmental risks such as antibiotic-resistant bacteria and antibiotic-resistant genes, posing a potential threat to the ecological environment and human health. Therefore, effectively removing antibiotic residues from the environment is a crucial problem that urgently needs to be addressed.

[0004] Currently, antibiotic pollution treatment methods are mainly divided into physical methods, chemical methods, and microbial degradation methods. Physical methods have high removal efficiency but cannot completely degrade antibiotics; they only concentrate the antibiotics, requiring further advanced treatment. Chemical methods are costly and can cause secondary pollution, making them unsuitable for large-scale use. In contrast, biological methods utilize the metabolic activity of microorganisms in the environment to oxidize and decompose antibiotics into stable, harmless inorganic substances, offering advantages such as no secondary pollution, mature technology, simple processes, and low operating costs. Currently, there are few high-quality microbial species capable of degrading chlortetracycline, and existing strains still have certain limitations: low degradation efficiency, long degradation cycles, and demanding growth conditions. Therefore, it is necessary to further search for chlortetracycline-degrading strains with good performance. This will not only help expand the application areas of antibiotic-degrading bacteria in environmental protection and antibiotic pollution treatment but also provide technical support and reference for antibiotic removal in aquatic environments. Summary of the Invention

[0005] To address the shortcomings of the prior art, the present invention aims to provide a paramyotrophic spp. and its application in the treatment of wastewater containing antibiotics.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a Bacillus paramycoides BCTC-2, which was deposited on July 23, 2025, at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 35352.

[0008] A second aspect of the present invention provides a bacterial agent comprising Bacillus paramyotrophicus BCTC-2 or a culture medium thereof.

[0009] A third aspect of the present invention provides an antibiotic degrading agent comprising Bacillus paramyophyte BCTC-2 or the above-described bacterial agent.

[0010] In a fourth aspect, the invention provides the use of Bacillus paramyxoides BCTC-2 or the above-mentioned bacterial agent or the above-mentioned degrading agent in the degradation of chlortetracycline.

[0011] A fifth aspect of the present invention provides a method for preparing the above-mentioned bacterial agent, comprising the step of culturing Bacillus paramyxobolus BCTC-2.

[0012] A sixth aspect of the present invention provides a method for degrading chlortetracycline, comprising inoculating or applying Bacillus paramyxoides BCTC-2 or the above-mentioned bacterial agent or the above-mentioned degrading agent to a material containing chlortetracycline for degradation, thereby performing degradation.

[0013] A seventh aspect of the present invention provides a method for treating chlortetracycline-contaminated wastewater, comprising treating the chlortetracycline-contaminated wastewater with Bacillus paramyxoides BCTC-2 or the above-mentioned bacterial agent or the degradation agent described above; wherein the chlortetracycline-contaminated wastewater is wastewater contaminated with chlortetracycline.

[0014] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: The *Bacillus paramycoides* BCTC-2 strain of the present invention is deposited at the China General Microbiological Culture Collection Center (CGMCC), with accession number CGMCC No. 35352, and deposit date July 23, 2025. This strain has strong chlortetracycline degradation ability and good environmental adaptability. Under the conditions of sodium citrate as an external carbon source, inoculum volume of 5%, temperature of 30℃, and pH=7, strain BCTC-2 can efficiently remove chlortetracycline at a concentration of 50 mg / L within 4 days, with a maximum degradation rate of 82.95%. Simultaneously, this strain also showed good chlortetracycline degradation effect in actual antibiotic-containing wastewater. Under the conditions of 30℃ and pH=7, strain BCTC-2 achieved a chlortetracycline degradation rate of 71.02% within 4 days, which is 62.5% higher than the control group without added bacterial solution. This strain can be used in the actual treatment of antibiotic-containing wastewater, which can reduce the pollution of the environment and the harm to human health caused by antibiotic residues. It provides a theoretical basis for the industrial application of highly efficient chlortetracycline-degrading bacteria, which is conducive to enriching the strain resource library of chlortetracycline-degrading bacteria and providing an effective biodegradation method for the treatment of antibiotic pollution in the environment. Attached Figure Description

[0015] Figure 1 shows the colony morphology of *Bacillus parasiticus* in Example 1 of this invention; Figure 2 shows the phylogenetic tree of *Bacillus parasiticus* in Example 2 of this invention; Figure 3 shows the growth and chlortetracycline degradation of *Bacillus parasiticus* under different carbon source conditions in Example 4 of this invention, with different letters indicating significant differences between treatments (P < 0.05); Figure 4 shows the growth and chlortetracycline degradation of *Bacillus parasiticus* under different initial chlortetracycline concentrations in Example 4 of this invention, with different letters indicating significant differences between treatments (P < 0.05); Figure 5 shows the degradation effect of *Bacillus parasiticus* under different inoculation amounts in Example 4 of this invention, with different letters indicating significant differences between treatments (P < 0.05). The differences were statistically significant (P<0.05); Figure 6 shows the growth of *Bacillus parasiticus* and the degradation of chlortetracycline under different temperature conditions in Example 4 of the present invention; different letters in the figure indicate significant differences between treatments (P<0.05); Figure 7 shows the growth of *Bacillus parasiticus* and the degradation of chlortetracycline under different pH conditions in Example 4 of the present invention; different letters in the figure indicate significant differences between treatments (P<0.05); Figure 8 shows the changes in the growth of *Bacillus parasiticus* and the degradation of chlortetracycline under optimal environmental conditions over time in Example 4 of the present invention; different letters in the figure indicate significant differences between treatments (P<0.05); Figure 9 shows the degradation of chlortetracycline by *Bacillus parasiticus* in actual antibiotic-containing wastewater in Example 5 of the present invention. Detailed Implementation

[0016] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0017] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, and / or combinations thereof.

[0018] In one typical embodiment of the present invention, a Bacillus paramycoides BCTC-2 is provided. Bacillus paramycoides BCTC-2 was deposited at the China General Microbiological Culture Collection Center on July 23, 2025, with the accession number CGMCC No. 35352.

[0019] The Bacillus paramycoides BCTC-2 strain described in this invention was obtained from activated sludge in a pharmaceutical factory through enrichment, domestication, isolation, and purification. The colonies of this strain are round, smooth, with neat edges, opaque, and pale yellow.

[0020] In another typical embodiment of the present invention, a bacterial agent is provided, comprising Bacillus paramyxobolus BCTC-2 or its culture medium.

[0021] In another typical embodiment of the present invention, an antibiotic degradation agent is provided, comprising Bacillus paramyxobolus BCTC-2 or the above-mentioned bacterial agent.

[0022] In some embodiments, the degrading agent further comprises an excipient for culturing Bacillus paramyxobolus BCTC-2, preferably sodium citrate. More preferably, the concentration of sodium citrate is 0.5 g / L.

[0023] In another typical embodiment of the present invention, the use of Bacillus paramyxoides BCTC-2 or the above-mentioned bacterial agent or the above-mentioned degrading agent in the degradation of chlortetracycline is provided.

[0024] In another typical embodiment of the present invention, a method for preparing the above-mentioned bacterial agent is provided, including the step of culturing Bacillus paramyxobolus BCTC-2.

[0025] In some embodiments, the steps include inoculating *Bacillus paramyotrophicus* BCTC-2 into LB liquid medium for culture, collecting the culture medium, centrifuging to obtain bacterial cells, and adjusting the OD of the bacterial culture after washing and resuspending the bacterial cells. 600 The concentration is 0.9~1.2, which yields the bacterial agent.

[0026] In some implementations, the culture conditions are: 30°C, 160 r / min, and cultured in the dark for 24 h.

[0027] In some embodiments, the culture medium is collected, centrifuged to obtain bacterial cells, and the bacterial cells are washed, resuspended, and then the bacterial concentration (OD) is adjusted. 600 The result is 1, which means the bacterial agent is obtained.

[0028] In some embodiments, the LB liquid medium is formulated as follows: 5 g / L yeast extract, 10 g / L peptone, 5 g / L sodium chloride, and the pH is adjusted to 7.

[0029] In another typical embodiment of the present invention, a method for degrading chlortetracycline is provided, comprising inoculating or applying Bacillus paramyxoides BCTC-2 or the above-mentioned bacterial agent or the above-mentioned degrading agent to a material containing chlortetracycline to be degraded, thereby carrying out degradation.

[0030] In some embodiments, the concentration of chlortetracycline in the material to be degraded is 50 mg / L.

[0031] In some embodiments, the material to be degraded includes LB medium containing chlortetracycline.

[0032] In some embodiments, the inoculation amount is 5%, and the OD of the Bacillus parasiticus BCTC-2 bacterial suspension in the bacterial agent is... 600 The value is 0.9~1.2, preferably 1.

[0033] In some embodiments, the optimal conditions for chlortetracycline degradation performance are: sodium citrate (0.5 g / L) as the external carbon source, 5% inoculum (OD600 = 1), initial chlortetracycline concentration of 50 mg / L, temperature of 30°C, and pH of 7.0.

[0034] Another typical embodiment of the present invention provides a method for treating wastewater containing antibiotics, comprising treating the wastewater containing antibiotics with Bacillus paramyophyllum BCTC-2 or the above-mentioned bacterial agent or the degradation agent described above; wherein the wastewater containing antibiotics is wastewater contaminated with chlortetracycline.

[0035] In some embodiments, the concentration of chlortetracycline in the wastewater is 50 mg / L.

[0036] In some implementations, the optimal conditions for wastewater treatment are: 30°C and pH=7.0.

[0037] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0038] Example 1 Isolation and screening of Bacillus paramycoides BCTC-2 strain (1) Enrichment and acclimatization of chlortetracycline-degrading bacteria: Activated sludge from a pharmaceutical factory was used as the inoculum for isolating chlortetracycline-degrading bacteria. 10 ml of activated sludge was inoculated into a conical flask containing 100 mL of enrichment medium, and then placed in a shaker at 30℃ and 160 r / min for 24 h. The sludge was thoroughly shaken to obtain a certain volume of sludge suspension. The composition of the enrichment liquid medium was: 3 g / L beef extract, 10 g / L peptone, 5 g / L NaCl, pH adjusted to 7, sterilized at 121℃ for 20 min, and cooled to room temperature. 10 mL of the suspension was added to 100 mL of inorganic salt medium with chlortetracycline concentrations of 10 mg / L, 20 mg / L, and 50 mg / L, respectively, for acclimatization. The experiment was conducted at 30℃ and 160 r / min. Every 7 days, the inoculum was transferred from the inorganic salt medium to a fresh inorganic salt medium at a rate of 10% (v / v), for three consecutive cycles. Finally, a culture medium tolerant to chlortetracycline was obtained through enrichment and acclimation. The inorganic salt medium consisted of: disodium hydrogen phosphate 0.5 g / L, sodium dihydrogen phosphate 0.5 g / L, sodium chloride 0.5 g / L, ammonium chloride 1 g / L, magnesium sulfate 0.2 g / L, and an appropriate amount of chlortetracycline. The pH was adjusted to 7.0, and the medium was sterilized at 121℃ for 20 min.

[0039] (2) Isolation and purification of chlortetracycline-degrading bacteria: The culture medium of the domesticated tolerant bacteria was serially diluted with sterile water to 10. -5 10 -6 and 10 -7 100 μL of bacterial suspension was spread onto a solid selection medium containing 50 mg / L chlortetracycline to isolate chlortetracycline-degrading bacteria. The plate was inverted and incubated at 30°C in the dark for 48 h, and the colonies were observed. Individual colonies were selected based on their morphology, color, and size. Each single colony was then purified by multiple streak plating. Finally, all purified strains were preserved at 4°C using the slant agar preservation method.

[0040] (3) Preparation of chlortetracycline-degrading bacterial suspension: The isolated and purified degrading strains were inoculated into liquid LB medium (5 g / L yeast extract, 10 g / L peptone, 5 g / L sodium chloride, pH adjusted to 7, sterilized at 121℃ for 20 min), and cultured at 30℃ and 160 r / min for 24 h. The culture was then collected, and the bacterial cells were obtained by centrifugation at 5000 r / min for 10 min. After washing and resuspending, the bacterial suspension concentration was adjusted from OD600 to 1 and used in the screening of superior chlortetracycline-degrading strains.

[0041] The prepared degrading bacterial suspensions were inoculated into selection medium containing 50 mg / L chlortetracycline for degradation experiments. The cultures were incubated at 30℃ and 160 r / min in the dark for 7 days. The supernatant was filtered through a 0.22 μm filter, and the chlortetracycline content in the medium was measured using a UV spectrophotometer to calculate the degradation efficiency of each strain. The strain with the highest chlortetracycline degradation efficiency was finally selected and named chlortetracycline degrading bacterium BCTC-2. The morphology of the purified chlortetracycline degrading bacterium BCTC-2 is shown in Figure 1. The colonies are round, smooth, with regular edges, opaque, and pale yellow in color.

[0042] Example 2: 16S rDNA gene sequencing of Bacillus paramycoides strain BCTC-2. Single colonies of BCTC-2 strain were collected on LB agar plates, and genomic DNA was extracted. Using total genomic DNA as a template, PCR amplification was performed using universal primers for the 16S rRNA gene. The amplified products were sent to a testing company for sequencing. The sequenced sequences were submitted to NCBI for BLAST alignment, and a phylogenetic tree was constructed using MEGA 7.0. The phylogenetic tree is shown in Figure 2. Phylogenetic analysis showed that this strain belongs to the same branch as Bacillus paramycoides. 。 Based on morphological characteristics and 16S rRNA sequence analysis, the strain BCTC-2 was identified as Bacillus paramycoides. This strain was deposited at the China General Microbiological Culture Collection Center (CGMCC) on July 23, 2025, at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, with accession number CGMCC No. 35352. Its 16S rDNA gene sequence is shown in SEQ ID NO: 1.

[0043]

[0044] Example 3: Preparation of the bacterial agent. Bacillus paramycoides BCTC-2 was inoculated into liquid LB medium (5 g / L yeast extract, 10 g / L peptone, 5 g / L sodium chloride, pH adjusted to 7, sterilized at 121℃ for 20 min). After culturing at 30℃ and 160 r / min in a shaker for 24 h, the culture was collected, and the cells were obtained by centrifugation at 5000 r / min for 10 min. After washing and resuspending, the bacterial concentration was adjusted from OD600 to 1 to obtain the bacterial agent.

[0045] Example 4: Effects of environmental conditions on the growth of Bacillus paramycoides BCTC-2 strain and its degradation efficiency of chlortetracycline. The effects of different carbon sources, initial chlortetracycline concentration, inoculum amount, temperature and pH on the growth of BCTC-2 strain and its degradation efficiency of chlortetracycline were investigated.

[0046] Regarding the types of external carbon sources, sodium citrate, sodium acetate, glucose, and tryptone were selected as external carbon sources. The optimal external carbon source was selected by investigating the effects of different carbon sources on the growth of strain BCTC-2 and the degradation of chlortetracycline. The total concentration of external carbon sources was maintained at 0.5 g / L, and a control group was set up with chlortetracycline as the sole carbon source. Other environmental conditions were controlled as follows: initial chlortetracycline concentration 50 mg / L, inoculum size 5%, temperature 30℃, and pH 7.0. The results are shown in Figure 3. Compared with the control group with chlortetracycline as the sole carbon source, the addition of all four external carbon sources increased the OD of strain BCTC-2. 600 The degradation values ​​and chlortetracycline degradation rates were analyzed. Among the carbon sources, sodium citrate showed the highest degradation efficiency (81.68%), exceeding that achieved with sodium acetate, glucose, and tryptone. Therefore, sodium citrate was selected as the optimal carbon source for further research.

[0047] This invention investigated the effects of different initial concentrations of chlortetracycline on the growth and degradation efficiency of strain BCTC-2. Five different initial chlortetracycline concentrations (10, 20, 30, 50, and 100 mg / L) were set up, along with a control group without BCTC-2 bacterial culture. Other environmental conditions were controlled as follows: sodium citrate as an external carbon source, 5% inoculum size, temperature 30℃, and pH 7.0. The results are shown in Figure 4. Compared to the control group, the addition of bacterial culture significantly improved the chlortetracycline degradation rate at all initial concentrations. The degradation rate initially increased and then decreased with increasing initial chlortetracycline concentration, reaching a maximum of 83.12% at an initial concentration of 50 mg / L. Furthermore, the OD of BCTC-2... 600The value showed the same trend as the degradation rate of chlortetracycline, reaching its maximum value at an initial concentration of 50 mg / L. The experimental results indicate that appropriately increasing the initial concentration of chlortetracycline can improve the biomass of BCTC-2 and the degradation rate of chlortetracycline, but biodegradation is inhibited when the concentration exceeds a certain range. Therefore, the initial concentration of chlortetracycline was controlled at 50 mg / L in subsequent studies.

[0048] Regarding the inoculum size, the seed culture of strain BCTC-2 was inoculated into the degradation experiments at inoculum sizes of 1%, 3%, 5%, 7%, and 10%, respectively. Other environmental conditions were controlled as follows: sodium citrate as the external carbon source, initial chlortetracycline concentration of 50 mg / L, temperature of 30℃, and pH of 7.0. The results are shown in Figure 5. Generally, the biomass of BCTC-2 and the degradation rate of chlortetracycline increased with increasing inoculum size. The degradation efficiency of strain BCTC-2 was similar at inoculum sizes of 5%, 7%, and 10%, with the highest degradation rate reaching 80.34%. Therefore, considering factors such as degradation efficiency and economics, a 5% inoculum size was selected for subsequent studies.

[0049] Regarding temperature studies, the degradation experiments were conducted at five different temperatures: 20℃, 25℃, 30℃, 35℃, and 40℃, to investigate the effect of ambient temperature on the growth of BCTC-2 and the degradation efficiency of chlortetracycline. A control group without BCTC-2 bacterial culture was also included. Other environmental conditions were controlled as follows: sodium citrate as the external carbon source, an initial chlortetracycline concentration of 50 mg / L, and pH 7.0. The results are shown in Figure 6. Compared with the control group, the addition of BCTC-2 significantly improved the degradation rate of chlortetracycline under all temperature conditions. Simultaneously, with increasing ambient temperature, the OD of BCTC-2 increased. 600 The degradation rate of chlortetracycline showed a trend of first increasing and then decreasing. Both low and high temperatures were not suitable for the growth and degradation of BCTC-2. When the ambient temperature was 30℃, it was the most suitable for the growth of BCTC-2 and could exert the best chlortetracycline degradation performance, with the best degradation rate reaching 82.95%.

[0050] In terms of pH investigation, this invention set up five experimental groups with different pH values ​​(5, 6, 7, 8, and 9) to investigate the effect of pH on the growth of BCTC-2 and the degradation of chlortetracycline. The results are shown in Figure 7. The addition of BCTC-2 inoculum significantly improved the degradation efficiency of chlortetracycline at all pH values. Meanwhile, with increasing pH, the biomass of BCTC-2 and the degradation rate of chlortetracycline showed a trend of first increasing and then decreasing. Compared with an acidic environment, the alkaline environment was more conducive to the growth of BCTC-2 and its degradation of chlortetracycline, but excessively high pH had a negative impact. The final results showed that pH 7 was the most suitable for BCTC-2 growth and achieved the best chlortetracycline degradation effect, with a degradation rate of 82.76%.

[0051] In summary, Bacillus paramycoides BCTC-2 strain can degrade chlortetracycline under different conditions. The optimal conditions for the growth of BCTC-2 and its degradation of chlortetracycline are: sodium citrate as the external carbon source, an initial concentration of chlortetracycline of 50 mg / L, an inoculum size of 5%, a temperature of 30℃, and a pH of 7.

[0052] Under optimal conditions of sodium citrate as an external carbon source, an initial concentration of chlortetracycline of 50 mg / L, an inoculum size of 5%, a pH of 7, and culture in the dark at 30°C, OD was measured every 24 h. 600 The growth and degradation of chlortetracycline by *Bacillus paramyxoides* BCTC-2 were investigated using different concentrations of chlortetracycline. The results, shown in Figure 8, indicate that chlortetracycline degradation mainly occurred during the biomass growth phase of BCTC-2. Between 24 and 72 h, both the growth of BCTC-2 and the degradation rate of chlortetracycline showed a rapid upward trend, with the degradation rate increasing rapidly from 31.23% to 77.09%. Subsequently, the degradation rate of chlortetracycline gradually decreased, and the bacteria entered the death phase, with the OD of the culture medium decreasing. 600 The value also gradually decreased, and the degradation rate of chlortetracycline reached 82.95% after 96 hours.

[0053] Example 5: Application of Bacillus paramycoides BCTC-2 strain in the treatment of antibiotic-containing wastewater. In this example, multiple samples of antibiotic-containing wastewater were measured, and BCTC-2 bacterial suspension was added at a volume ratio of 5%. A control group without BCTC-2 bacterial suspension was also included. Three replicate experiments were performed for each group. The wastewater was then incubated at 30℃ in the dark for 7 days. The chlortetracycline content in the wastewater was measured, and its degradation efficiency was calculated. The results are shown in Figure 9. The figure shows that BCTC-2 has a good degradation effect on chlortetracycline in actual antibiotic-containing wastewater, with a degradation rate of 71.02% after 4 days of treatment. In contrast, the degradation rate of chlortetracycline in the control group without BCTC-2 inoculation was only 8.52%. The degradation rate of chlortetracycline in the inoculated treatment group was 62.5% higher than that in the control group.

[0054] Therefore, the Bacillus paramycoides BCTC-2 provided by this invention has a good degradation ability for chlortetracycline. Through optimization of culture conditions, its degradation efficiency can reach about 82.95% under optimal conditions. It can also be applied to the treatment of wastewater containing antibiotics, achieving a degradation rate of 71.02% in antibiotic-containing wastewater after 4 days.

[0055] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of them. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A Bacillus paramycoides BCTC-2, characterized in that, The aforementioned *Bacillus paramyophyte* BCTC-2 was deposited on July 23, 2025, at the China General Microbiological Culture Collection Center (CGMCC), with accession number CGMCC No. 35352.

2. A microbial agent, characterized in that, It contains the *Bacillus paramyxobolus* BCTC-2 or its culture medium as described in claim 1.

3. An antibiotic degrading agent, characterized in that, It contains the Bacillus paramyxobolus BCTC-2 as described in claim 1 or the bacterial agent as described in claim 2.

4. The degrading agent as described in claim 3, characterized in that, It also contains excipients for culturing Bacillus paramyxobolus BCTC-2.

5. The method for preparing the microbial agent according to claim 2, characterized in that, This includes the steps of culturing Bacillus paramyxobolus BCTC-2.

6. The preparation method according to claim 5, characterized in that, The steps include inoculating *Bacillus paramyophyte* BCTC-2 into LB liquid medium for culture, collecting the culture medium, centrifuging to obtain bacterial cells, and then adjusting the OD of the bacterial culture after washing and resuspending the bacterial cells. 600 The concentration is 0.9~1.2, which yields the bacterial agent.

7. The use of the Bacillus parasiticus BCTC-2 of claim 1, the bacterial agent of claim 2, or the degrading agent of any one of claims 3-4 in the degradation of antibiotics.

8. The application as described in claim 7, characterized in that, The antibiotic in question is chlortetracycline.

9. A method for degrading chlortetracycline, characterized in that, This includes inoculating or applying the *Bacillus parasiticus* BCTC-2 of claim 1, the bacterial agent of claim 2, or the degrading agent of any one of claims 3-4 to the material to be degraded containing chlortetracycline, thereby causing degradation.

10. A method for treating wastewater containing anti-fouling agents, characterized in that, The wastewater containing antibiotics is treated by using the Bacillus parasiticus BCTC-2 of claim 1, the bacterial agent of claim 2, or the degradation agent of any one of claims 3-4; the wastewater containing antibiotics is wastewater contaminated with chlortetracycline.

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