Staphylococcus capitis capable of tolerating and efficiently degrading PFOS and application thereof

Abstract

The invention belongs to the field of microorganisms, and discloses staphylococcus capitis capable of tolerating and efficiently degrading PFOS and application of the staphylococcus capitis. The name of the staphylococcus capitis is staphylococcus capitis subsp. Urealyticus Q2, the preservation number of the staphylococcus capitis is GDMCC No: 67647, and the staphylococcus capitis is preserved in the Guangdong Microbial Culture Collection Center on January 13, 2026, and the preservation number of the staphylococcus capitis is CGMCC No: 67647. The strain can grow in an environment of PFOS (Perfluorooctane Sulfonate) up to 80mg / L, and the degradation rate of the strain to the PFOS with the initial concentration of 0.05 mg / L reaches about 85%; and the strain can grow in an environment with the NaCl concentration as high as 7%. Therefore, the compound can be used for degrading PFOS.

Description

Technical Field

[0001] This invention belongs to the field of microbiology, and specifically relates to a Staphylococcus capillus strain that is tolerant to and highly efficient at degrading PFOS and its applications. Background Technology

[0002] Perfluorooctane sulfonate (PFOS) is a typical representative of the polyfluoroalkyl substances (PFAS) family, with the chemical structure C8F. 17 SO3H has a characteristic structure of perfluoroalkyl chains bonded to sulfonic acid groups. [1] This structure endows PFOS with extremely strong chemical stability. Its carbon-fluorine (CF) bond dissociation energy is as high as 450 kJ / mol, far exceeding that of carbon-chlorine (330 kJ / mol) and carbon-bromine (194 kJ / mol) bonds. This enables it to resist various degradation pathways such as chemical oxidation and high temperatures, exhibiting extremely strong persistence in the environment. [2] At the same time, PFOS possesses both hydrophobic and oleophobic properties, along with high surface activity, making it widely used in industrial and consumer products. These applications include its use as an additive in fire-fighting foams, a water and oil repellent agent for textiles and paper, a surfactant in electroplating solutions, and a coating for food packaging materials. [1][3] .

[0003] PFOS can enter the environment through various pathways. Direct sources include emissions during production, leaks during product use, and disposal of waste products. Indirect sources mainly consist of precursors that are generated in the environment through biological or chemical transformation. [1] Due to its high water solubility and stability, PFOS is widely distributed in the global environment and has been detected in surface water, groundwater, soil, sediments, atmosphere, and in plants and animals. It has even been found in remote areas such as Arctic snow and glacial meltwater. [2][3] For example, PFOS concentrations in rivers and lakes worldwide can reach levels from ng / L to μg / L, while near contaminated industrial sites, concentrations can be as high as mg / L. [1] PFOS in the environment can pose various health risks to humans. Studies have shown that environmental PFOS can accumulate in human tissues such as blood and liver, and are associated with a variety of health problems, including thyroid disease, liver damage, abnormal cholesterol levels, weakened immune function, and developmental toxicity. [2][3] Epidemiological surveys show that serum PFOS levels in occupationally exposed individuals are significantly higher than in the general population, and are associated with abnormal liver function indicators and thyroid hormone disorders. [3] .

[0004] Currently, the main methods for degrading PFOS include physicochemical and biological methods. Among physicochemical methods, high-temperature incineration requires temperatures above 800°C to decompose PFOS, resulting in extremely high energy consumption and the potential release of toxic byproducts. While advanced oxidation technologies can break CF bonds, they require stringent reaction conditions and sophisticated equipment, and their efficiency significantly decreases in complex matrices. [2][4] Adsorption can temporarily remove PFOS from water, but it suffers from problems such as difficulty in regeneration after adsorption saturation and the potential for secondary pollution. [2] In contrast, biodegradation methods offer advantages such as environmental friendliness, low cost, and ease of operation. Through the metabolic processes of microorganisms, PFOS can be converted into short-chain fluorides or partially mineralized, making them suitable for large-scale in-situ remediation. [2] Studies have identified several microorganisms capable of degrading PFOS. *Pseudomonas aeruginosa* and *Pseudomonas putida*, both belonging to the genus *Pseudomonas*, exhibited PFOS degradation activity under pure culture conditions. [5] In anaerobic environments, *Acidimicrobium* sp. A6 can degrade PFOS via the iron reduction metabolic pathway, achieving a removal rate of approximately 40% for 10 mg / L PFOS over 120 days of culture. Furthermore, the abundance of bacteria such as *Desulfosporosinus* increased in its enrichment cultures, suggesting a possible synergistic role in the degradation process. [6] Under sulfur-limited conditions, the Rhodococcus jostii RHA1 strain can promote the biotransformation of PFOS by catalyzing the desulfonation of PFOS via alkyl sulfonate monooxygenase, while simultaneously achieving defluorination with the aid of alkyl monooxygenase and cytochrome P450. [7] These microorganisms provide diverse resources for the bioremediation of PFOS contamination through different metabolic pathways. However, currently known PFOS-degrading strains are few, and their degradation efficiency is generally low. [2] Given the widespread pollution and potential hazards of PFOS, identifying highly efficient degrading microorganisms is of great significance for developing economically feasible pollution control technologies, and related research has become an urgent need in the field of environmental science.

[0005] References:

[0006] [1] Prevedouros K, Cousins ​​IT, Buck RC, et al. Sources, fate and transport of perfluorocarboxylates[J]. Environmental science & technology, 2006, 40(1): 32-44.

[0007] [2] Thapa B S, Pandit S, Mishra R K, et al. Emergence of per-andpoly-fluoroalkyl substances (PFAS) and advances in the remediation strategies[J]. Science of the Total Environment, 2024, 916: 170142.

[0008] [3] Lau C, Anitole K, Hodes C, et al. Perfluoroalkyl acids: a reviewof monitoring and toxicological findings[J]. Toxicological sciences, 2007, 99(2): 366-394.

[0009] [4] Kumar R, Dada T K, Whelan A, et al. Microbial and thermaltreatment techniques for degradation of PFAS in biosolids: A focus ondegradation mechanisms and pathways[J]. Journal of hazardous materials, 2023,452: 131212.

[0010] [5] Chiriac F L, Stoica C, Iftode C, et al. Bacterial biodegradationof perfluorooctanoic acid (PFOA) and perfluorosulfonic acid (PFOS) using purePseudomonas strains[J]. Sustainability, 2023, 15(18): 14000.

[0011] [6] Huang, Shan, et al. Defluorination of various perfluoro alkylacids and selected PFOA and PFOS monomers by Acidimicrobium sp. Strain A6enrichment cultures. Journal of Hazardous Materials 480 (2024): 136426.

[0012] [7] Yang SH, Shi Y, Strynar M, et al. Desulfonation anddefluorination of 6: 2 fluorotelomer sulfonic acid (6: 2 FTSA) by Rhodococcusjostii RHA1: Carbon and sulfur sources, enzymes, and pathways[J]. Journal ofhazardous materials, 2022, 423: 127052. Summary of the Invention

[0013] The primary objective of this invention is to overcome the shortcomings and deficiencies of the prior art and provide a Staphylococcus capillaris strain that is tolerant to and highly efficient at degrading PFOS.

[0014] Another object of the present invention is to provide the application of the above-mentioned Staphylococcus aureus that is resistant to and efficiently degrades PFOS.

[0015] The objective of this invention is achieved through the following technical solution: a Staphylococcus capitis strain that is tolerant to and highly efficient at degrading PFOS, named Staphylococcus capitis subsp. urealyticus Q2, with accession number GDMCC No: 67647, was deposited on January 13, 2026, at the Guangdong Provincial Microbial Culture Collection Center of the Institute of Microbiology, Guangdong Academy of Sciences, located on the 5th floor of Building 59, No. 100 Xianlie Middle Road, Guangzhou.

[0016] The application of the above-mentioned Staphylococcus aureus strains that are tolerant to and highly efficient at degrading PFOS in the degradation of PFOS.

[0017] The PFOS mentioned refers to PFOS that exist in soil and water bodies.

[0018] A microbial preparation containing Staphylococcus capillus tolerating and efficiently degrading PFOS as described above.

[0019] The microbial preparation is the above-mentioned Staphylococcus aureus fermentation broth or lyophilized powder that is resistant to and highly efficient at degrading PFOS.

[0020] The application of the above-mentioned microbial agents in the degradation of PFOS.

[0021] The PFOS mentioned refers to PFOS that exist in soil and water bodies.

[0022] The present invention has the following advantages and effects compared with the prior art:

[0023] This invention provides for the first time a Staphylococcus aureus strain that is tolerant to and highly efficient at degrading PFOS, capable of growing in environments with up to 80 mg / L of PFOS, and achieving a degradation rate of approximately 85% for an initial concentration of 0.05 mg / L of PFOS; moreover, it can grow in environments with NaCl concentrations up to 7%. Attached Figure Description

[0024] Figure 1 This is a photograph of the colony morphology of strain Q2.

[0025] Figure 2 This is a phylogenetic tree based on the 16S rRNA gene sequence of Staphylococcus capitis subsp. urealyticus Q2 and its related bacteria, constructed using the neighbor-joining method; where the expansion value is set to 1000 repetitions, and the scale bar 0.01 represents the substitution rate of each nucleotide.

[0026] Figure 3 This is a graph showing the effect of different growth temperatures on the strain Staphylococcus capitis subsp. urealyticus Q2.

[0027] Figure 4 This is a graph showing the effect of different growth pH on the strain Staphylococcus capitis subsp. urealyticus Q2.

[0028] Figure 5 This is a graph showing the effect of different salinities on the strain Staphylococcus capitis subsp. urealyticus Q2.

[0029] Figure 6 This is a graph showing the effect of different initial PFOS concentrations on the strain Staphylococcus capitis subsp. urealyticusQ2.

[0030] Figure 7 This is a graph showing the results of the degradation ability of Staphylococcus capitis subsp. urealyticus Q2 on different initial concentrations of PFOS.

[0031] Figure 8 This is a graph showing the results of the strain's degradation rate of PFOS over time. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0033] Unless otherwise specified in the following implementation plan, the test conditions are generally as per standard test conditions or the test conditions recommended by the reagent company. Unless otherwise specified, all materials and reagents used are commercially available.

[0034] Example 1

[0035] 1. Materials

[0036] 1.1 Sample source: Farmland soil from Qingyuan City, Guangdong Province.

[0037] 1.2 Culture medium

[0038] 1.2.1 Inorganic Salt Culture Medium

[0039] Inorganic salt culture medium was used for the enrichment culture of microorganisms in samples and for PFOS degradation experiments under pure bacterial conditions. The formulation of this medium is shown in Table 1, and it does not contain PFOS. Unless otherwise specified, the pH of the medium was adjusted to 7.0–7.2.

[0040] Table 1 Inorganic Salt Culture Medium Formulation

[0041]

[0042] 1.2.2 Nutrient Culture Medium

[0043] LB nutrient medium is used for the isolation, purification, preservation, and activation of bacteria and other routine microbial cultures. The types and components of the liquid nutrient media used in this experiment are shown in Table 2. If a solid nutrient medium needs to be prepared for the experiment, simply add 1.5% agar powder to the existing medium formula. Unless otherwise specified, the pH of the medium should be adjusted to 7.0–7.2.

[0044] Table 2 Components of the nutrient culture medium

[0045]

[0046] 2 Methods

[0047] 2.1 Domestication, screening and isolation of strains

[0048] An inorganic salt medium containing 100 mg / L PFOS was prepared to obtain an inorganic salt medium with PFOS as the sole carbon source. 1 g of collected farmland soil was added to 100 mL of the inorganic salt medium with PFOS as the sole carbon source, and the medium was placed in a 37℃ incubator with light-protected shaking (180 rpm) for enrichment and acclimatization. One acclimatization cycle was 7 days. Then, a 10% v / v inoculum was transferred to a fresh inorganic salt medium with the same culture system and the enrichment process was repeated three times.

[0049] The fourth-generation enriched culture samples obtained above were spread and isolated on LB solid medium using the dilution plate method. The spread samples were incubated at 37°C for 48 hours, after which distinct single colonies formed on the surface of the medium. Several single colonies with different characteristics were selected based on their morphology, size, color, and transparency, and then streaked and purified on nutrient medium plates. If single colonies with different characteristics were still observed on the purified plates, they were streaked again until only single colonies with the same characteristics were observed on the same plate. A strain Q2 with highly efficient PFOS degradation capabilities was screened in the experiment. The purified Q2 single colonies were picked and cultured in the corresponding liquid LB medium until the logarithmic growth phase. The bacterial culture was mixed with sterile glycerol and aliquoted into sterile 2 mL cryovials (glycerol concentration 25%), and stored at -80°C for long-term preservation.

[0050] 2.2 Morphological characteristics of strain Q2

[0051] Strain Q2 is a bacterium isolated from farmland soil. After activation, it was grown for 48 hours on a plate made of solid LB medium under aerobic conditions at 37°C. The colonies exhibited the following characteristics: Figure 1 The colonies shown are milky white, round, smooth, opaque, with neat edges, and without flagella.

[0052] 2.3 Identification of the molecular biological characteristics of strain Q2

[0053] Molecular biological characterization mainly includes DNA G+C content determination and Q2 genome sequencing and phylogenetic tree construction of the isolated strains. These experiments can provide scientific evidence for the taxonomic positioning of bacteria.

[0054] 2.3.1 DNA G+C content determination

[0055] The determination of DNA G+C content mainly used high performance liquid chromatography. The specific steps were described in the report by Mesbah et al. (1989). The DNA G+C content of strain Q2 was determined to be 33.63%.

[0056] 2.3.2 Sequencing and Construction of Phylogenetic Tree

[0057] Before sequencing and constructing a phylogenetic tree, bacterial DNA needs to be extracted (the rapid bacterial genomic DNA extraction kit used in the experiment was from Guangdong Megagene Technology Co., Ltd.). For bacterial taxonomy studies, it is usually necessary to amplify the 16S rRNA gene and construct a phylogenetic tree. The amplified gene is a segment of DNA encoding rRNA in prokaryotes, and due to its high conservation, specificity, and suitable sequence length, it is commonly used for detecting and identifying bacteria.

[0058] Polymerase chain reaction (PCR) requires 27F and 1492R primers to amplify 16S rRNA (Baker et al., 2003). The PCR amplification reaction system is as follows: 1 μL of forward primer 27F (10 mmol / L), 1 μL of reverse primer 1492R (10 mmol / L), 12.5 μL of Taq enzyme, 1 μL of DNome template, and 9.5 µL of deionized water. PCR amplification conditions: 95℃ for 5 min; 30 cycles of 95℃ for 30 s, 55℃ for 30 s, and 72℃ for 90 s; 72℃ for 5 min. After the PCR reaction, the sample was stored at 4℃. A gel block was prepared using 1%–1.5% agarose and nucleic acid staining agent. PCR products and DNA markers of various lengths were added to the sample wells of the gel block, and the gel was placed in an electrophoresis apparatus filled with TAE buffer. After operating the electrophoresis apparatus at a specific voltage for 20 minutes, the gel was removed and observed under a 300 nm UV lamp to confirm successful PCR amplification. The successfully amplified PCR products were then sent to Tianyi Huiyuan Gene Technology Co., Ltd. for sequencing, using the same primers as the amplification primers. Gene sequencing of the PCR products yielded a 1426 bp 16S rRNA gene sequence, as shown in SEQ ID NO.1. Simultaneously, the bacterial culture of the strain was sent to Tianyi Huiyuan Gene Technology Co., Ltd. for genome sequencing.

[0059] 16S rRNA gene:

[0060]

[0061] Forward primer 27F: 5'-AGAGTTTGATCCTGGCTCAG-3';

[0062] Reverse primer 1492R: 5'-TACGGCTACCTTGTTACGACTT-3'.

[0063] The 16S rRNA gene sequences obtained from sequencing were uploaded to NCBI for comparison to obtain the similarity between the obtained strains and the 16S rRNA genes in the database, thereby identifying the phylogenetic information of the isolated strains. Phylogenetic trees were constructed using the MEGA 5.05 program (Tamura et al., 2011), typically employing the neighbor-joining method with a bootstrap value set to 1000 replicates (Felsenstein et al., 1985). A phylogenetic tree was constructed using the 16S rRNA gene sequence of strain Q2 and 16S rRNA gene sequences with high similarity to it, thus obtaining the homology results between the strain and its highly similar 16S rRNA genes. The phylogenetic tree constructed using the neighbor-joining method is shown below. Figure 2 As shown, the results indicate that the isolated strain Q2 has a high similarity to Staphylococcus strains and the highest homology with Staphylococcus capitis subsp. urealyticus DSM6717, therefore it was named Staphylococcus capitis subsp. urealyticus Q2. The average nucleotide identity (ANI) value between the genome sequence of strain Q2 and known strains is the highest at 96.30%, therefore Q2 is a different strain of Staphylococcus capitis subsp. urealyticus.

[0064] The preservation information for Staphylococcus capitis subsp. urealyticus Q2 is as follows: the depositary institution is Guangdong Provincial Microbial Culture Collection Center (GDMCC), the accession number is GDMCC No: 67647, the depositary address is the Institute of Microbiology, Guangdong Academy of Sciences, 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, and the deposit date is January 13, 2026.

[0065] 2.4 Growth conditions of strain Staphylococcus capitis subsp. urealyticus Q2

[0066] 2.4.1 Determination of growth temperature

[0067] Liquid LB medium was prepared to support the growth of strain *Staphylococcus capitis* subsp. *urealyticus* Q2, and then sterilized in an autoclave. The activated strain *Staphylococcus capitis* subsp. *urealyticus* Q2 was inoculated into the medium at a rate of 1% v / v as the experimental group. Uninoculated medium served as the control group. Both groups were incubated at different temperatures (10℃, 20℃, 30℃, 37℃, 50℃, and 60℃), with three replicates for each temperature. Bacterial growth was observed at 0.5 h, 1.5 h, 2.5 h, 3 h, 4 h, 5 h, 7 h, and 10 h. The absorbance of the medium at λ = 600 nm was measured using a visible-ultraviolet spectrophotometer. Finally, the suitable temperature range and optimal growth temperature for *Staphylococcus capitis* subsp. *urealyticus* Q2 were determined. Results are as follows: Figure 3 As shown, in liquid LB medium, the strain Staphylococcus capitis subsp. urealyticus Q2 can grow at temperatures of 30–40°C, with the optimal growth temperature being 37°C.

[0068] 2.4.2 Determination of growth pH

[0069] Prepare the liquid nutrient medium required for the growth of strain Staphylococcus capitis subsp. urealyticus Q2, and adjust the pH of the culture medium using the following buffer system: 0.1 mol / L sodium citrate and 0.1 mol / L citric acid for pH 5.0, 0.1 mol / L NaOH and 0.1 mol / L KH2PO4 for pH 6.0-8.0, and 0.1 mol / L NaHCO3 and 0.1 mol / L Na2CO3 for pH 9.0 (Zhang et al., 2009). The strain *Staphylococcus capitis subsp. urealyticus* Q2 was inoculated into culture media at different pH values ​​at a 1% v / v inoculum as experimental groups, with uninoculated culture media serving as controls. Each pH was replicated three times. The liquid nutrient medium was incubated at the optimal growth temperature of 37℃. Bacterial growth was observed at 0.5 h, 1.5 h, 2.5 h, 3 h, 4 h, 5 h, 7 h, and 10 h. The absorbance of the culture medium at a wavelength of λ=600 nm was measured using a visible-ultraviolet spectrophotometer. Finally, the pH range and optimal growth pH of strain *Staphylococcus capitis subsp. urealyticus* Q2 were determined. Results are as follows: Figure 4 As shown, the strain *Staphylococcus capitis* subsp. *urealyticus* Q2 can grow under pH conditions ranging from 5.0 to 8.0, with the optimal growth pH being 7.0. When the pH varies within the range of 5–7, the OD values ​​of the strain at different time points are... 600 The values ​​did not differ significantly; however, when the pH increased to 8.0, the OD... 600 It decreased rapidly.

[0070] 2.4.3 Salt concentration tolerance

[0071] Liquid LB medium was prepared to support the growth of Staphylococcus capitis subsp. urealyticus Q2. The salt concentration of the medium was adjusted by changing the amount of NaCl added, which were 0%, 0.5%, 1%, 3%, 5%, and 7% by mass and volume, respectively. The pH of the medium was 7.0. Activated *Staphylococcus capitis* subsp. *urealyticus* Q2 bacteria were inoculated into sterilized liquid LB medium at a 1% v / v inoculum as the experimental group, with uninoculated medium serving as the control group. Three replicates were performed for each salt concentration. Both experimental and control groups were incubated under the optimal growth conditions for *Staphylococcus capitis* subsp. *urealyticus* Q2 (37℃, pH 7.0). Bacterial growth was observed at 0.5 h, 1.5 h, 2.5 h, 3 h, 4 h, 5 h, 7 h, and 10 h. The absorbance of the medium at λ = 600 nm was measured using a visible-ultraviolet spectrophotometer. Finally, the range of salt concentrations that the new bacteria could tolerate was determined. Results are as follows: Figure 5 As shown, *Staphylococcus capitis* subsp. *urealyticus* Q2 can grow in a salinity range of 0%–7%. When the salinity increases from 0 to 0.5%, the OD of the strain… 600 The trend was increasing, and then the salt concentration in the culture medium was increased to 7%, OD 600 The continuously decreasing salt concentration indicates that the optimal salt concentration for the growth of Staphylococcus capitis subsp. urealyticus Q2 is 0.5%.

[0072] 2.4.4 PFOS Tolerance Concentration

[0073] Prepare liquid LB medium for the growth of Staphylococcus capitis subsp. urealyticus Q2, add PFOS stock solution, and adjust the PFOS concentration in the medium to 1 mg / L, 10 mg / L, 20 mg / L, 40 mg / L, 80 mg / L, and 160 mg / L, respectively, and set the pH of the medium to 7.0. Activated *Staphylococcus capitis subsp. urealyticus* Q2 strain was inoculated into sterilized liquid nutrient medium as the experimental group, and uninoculated medium served as the control group. Three replicates were performed for each PFOS concentration. Both experimental and control groups were incubated under the optimal growth conditions for *Staphylococcus capitis subsp. urealyticus* Q2 (37℃, 0.5% NaCl, pH=7.0). Bacterial growth was observed at 0.5 h, 1.5 h, 2.5 h, 3 h, 4 h, 5 h, 7 h, and 10 h. The absorbance of the medium at λ=600 nm was measured using a visible-ultraviolet spectrophotometer. The growth of strain *Staphylococcus capitis subsp. urealyticus* Q2 under different initial PFOS concentrations was then obtained. Results are as follows: Figure 6 As shown, *Staphylococcus capitis* subsp. *urealyticus* Q2 can grow at PFOS concentrations of 1–80 mg / L, but cannot grow at 160 mg / L. The OD of the strain varies within the PFOS concentration range of 1–160 mg / L. 600 The concentration of PFOS first increased and then decreased; at a concentration of 10 mg / L, the OD of the strain... 600 The highest values ​​were observed. At PFOS concentrations of 1 mg / L, 20 mg / L, and 40 mg / L, the strain's OD value was... 600 The difference was not significant; at a PFOS concentration of 80 mg / L, the OD of the strain was [not specified]. 600 The concentrations were significantly lower than those treated with PFOS concentrations of 1 mg / L to 40 mg / L.

[0074] Example 2

[0075] 2.5 Degradation capacity of strain Staphylococcus capitis subsp. urealyticus Q2 for different initial PFOS concentrations

[0076] Based on the above experimental results, the optimal growth conditions for the strain were determined to be: temperature 37℃, pH 7.0, and 0.5% NaCl. Degradation experiments of strain *Staphylococcus capitis* subsp. *urealyticus* Q2 at different initial PFOS concentrations were conducted under these conditions. The strain *Staphylococcus capitis* subsp. *urealyticus* Q2 in the logarithmic growth phase was centrifuged at 25℃ and 5000 r / min to collect the cells. The cells were washed twice with inorganic salt medium, then resuspended in inorganic salt medium, and the OD was adjusted. 600 =1, to obtain Staphylococcus capitis subsp. urealyticus Q2 bacterial suspension. At an inoculation rate of 5% v / v, Staphylococcus capitis subsp. urealyticus Q2 bacterial suspension was inoculated into inorganic salt media containing initial PFOS concentrations of 0.05 mg / L, 0.10 mg / L, 0.20 mg / L, 0.5 mg / L, and 1 mg / L, respectively. The media were shaken and cultured, and the experiment was performed in triplicate. After 20 days of culture, samples were taken to determine the PFOS content. Simultaneously, the experiment without inoculation served as a sterile control.

[0077] PFOS concentration was determined using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS-8050) with electrospray ionization (ESI) in negative ion mode. A Waters XBridge BEH C18 VanGuard column (2.5 μm, 2.1 mm × 5 mm) connected to an XBridge BEHC18 guard column (2.5 μm, 2.1 × 100 mm) was used. The mobile phase consisted of ultrapure water (A) containing 0.05% ammonia and chromatographic grade methanol (B). The gradient elution program was as follows: initially, mobile phase A was 95% and mobile phase B was 5%; from 0.5 to 8 minutes, the mobile phase B reached 100% mobility and was maintained for 1.5 minutes; subsequently, the mobile phase A was maintained at 95% and mobile phase B at 5% for 15 minutes. The atomizer flow rate is 3 L / min; the heater flow rate is 10 L / min; the interface temperature is 300℃; the DL temperature is 250℃; the heating block temperature is 400℃; and the drying gas flow rate is 10 L / min.

[0078] The degradation of PFOS by strain Staphylococcus capitis subsp. urealyticus Q2 at different initial concentrations is as follows: Figure 7As shown, when the PFOS concentration varied within the range of 0.05 mg / L to 1 mg / L, the degradation rate of PFOS by this bacterium after 20 days ranged from 80.00% to 27.63%, gradually decreasing with increasing concentration. The highest degradation rate of 80.00% was observed at a PFOS concentration of 0.05 mg / L. When the PFOS concentration increased from 0.05 mg / L to 0.50 mg / L, the degradation rate rapidly decreased to 31.48%, and then slowly decreased to 27.63% with further increases in PFOS concentration.

[0079] 2.6 Changes in PFOS degradation rate of the strain over time

[0080] The degradation rate of PFOS by strain *Staphylococcus capitis* subsp. *urealyticus* Q2 over time with different initial concentrations was investigated at 37℃, pH 7.0, and 0.5% NaCl. The strain in logarithmic growth phase was centrifuged at 25℃ and 5000 r / min to collect the cells. The cells were washed twice with inorganic salt medium, centrifuged twice during the washing process at 25℃ and 5000 r / min, and then resuspended in inorganic salt medium to adjust the OD value. 600 =1, to obtain bacterial suspension. The bacterial suspension was inoculated at a 5% v / v inoculum into inorganic salt media containing initial concentrations of 0.05 mg / L, 0.2 mg / L, and 1 mg / L PFOS, respectively. The media were shaken and cultured in triplicate. Samples were taken at 5, 12, 20, and 30 days of culture to determine the PFOS content and calculate the degradation rate. An experiment without inoculation was used as a sterile control.

[0081] The degradation rate of PFOS by Staphylococcus capitis subsp. urealyticus Q2 over time is as follows: Figure 8 As shown, the degradation rate of PFOS by the strain continuously increased with the extension of culture time. During the period from 0 to 20 days, the degradation rate of PFOS increased rapidly with the extension of culture time. When the culture time was further extended to 30 days, the rate of increase in degradation rate gradually slowed down. For example, at 5, 12, 20, and 30 days, the degradation rates of PFOS at an initial concentration of 0.05 mg / L were 18.23%, 48.68%, 80.00%, and 84.91%, respectively. At 20 and 30 days, the degradation rates of PFOS at initial concentrations of 0.2 mg / L and 1 mg / L increased from 50.29% and 27.63% to 53.91% and 30.12%, respectively.

[0082] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A Staphylococcus aureus strain that is tolerant to and highly efficient at degrading PFOS, characterized in that: The PFOS-tolerant and highly efficient PFOS-degrading Staphylococcus capitis subsp. urealyticus Q2, with accession number GDMCC No: 67647, was deposited on January 13, 2026, at the Guangdong Provincial Microbial Culture Collection Center of the Institute of Microbiology, Guangdong Academy of Sciences, located on the 5th floor of Building 59, No. 100 Xianlie Middle Road, Guangzhou.

2. The application of the Staphylococcus capillus-cephala that is tolerant to and highly efficient at degrading PFOS as described in claim 1 in the degradation of PFOS.

3. The application of the Staphylococcus capillus-cephala strain that is tolerant to and highly efficient at degrading PFOS according to claim 2 in the degradation of PFOS, characterized in that: The PFOS mentioned refers to PFOS that exist in soil and water bodies.

4. A microbial preparation, characterized in that: The Staphylococcus capillus subtilis containing the PFOS-tolerant and highly efficient PFOS-degrading strain described in claim 1.

5. The microbial preparation according to claim 4, characterized in that: The microbial preparation is the Staphylococcus capitella fermentation broth or lyophilized powder that is resistant to and highly efficient at degrading PFOS as described in claim 1.

6. The use of the microbial preparation according to claim 4 or claim 5 in the degradation of PFOS.

7. The application of the microbial agent according to claim 6 in the degradation of PFOS, characterized in that: The PFOS mentioned refers to PFOS that exist in soil and water bodies.

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