Rhodococcus zopfii zq-1 and application thereof in degradation of organic pollutants in aerobic and anaerobic systems

Abstract

This invention provides a facultative Rhodococcus ZQ-1 and its application in the degradation of organic pollutants in aerobic and anaerobic systems. A Rhodococcus ( Rhodococcus sp.) ZQ-1, deposited at the China Center for Type Culture Collection (CCTCC), accession number CCTCC NO: M 2026457. The strain provided by this invention exhibits good degradation effects on organic pollutants, producing excellent degradation results even with low initial inoculum levels. Furthermore, this strain has a wide optimal growth pH range and a high degradation rate. When applied to aerobic and anaerobic systems for degrading organic pollutants, it is simple to operate, stable, low-cost, easy to manage, and provides mild reaction conditions, making it environmentally friendly.

Description

Technical Field

[0001] This invention pertains to a biodegradation technology for organic compounds, and specifically relates to a facultative erythrococcus (…). Rhodococcus sp.) ZQ-1 and its application in the degradation of organic pollutants in aerobic and anaerobic systems. Background Technology

[0002] Acrylonitrile is an important basic organic chemical raw material, widely used in the synthesis of polyacrylonitrile, ABS resin, styrene-butadiene rubber, and other polymer materials. However, it is volatile and toxic, and during production, storage, and use, it is easily released into the environment through waste gas and wastewater, causing pollution not only to the atmosphere, soil, and water bodies, but also harming human health through respiratory and skin contact. Long-term exposure may lead to damage to the nervous system and respiratory diseases.

[0003] Waste gas generated during wastewater treatment in industries such as petrochemicals often contains olefinic organic pollutants such as acrylonitrile and butadiene. Currently, the main methods for treating acrylonitrile waste gas include physicochemical methods such as adsorption and combustion. However, these methods suffer from high investment and operating costs and are prone to secondary pollution. Biological treatment methods, especially biofiltration and biowashing technologies, are considered a promising alternative due to their low cost, high efficiency, and lack of secondary pollution. The core of this technology lies in obtaining highly efficient and stable degradative microorganisms.

[0004] Currently reported acrylonitrile-degrading bacteria are limited in species, and they generally suffer from low degradation efficiency and weak adaptability to environmental conditions (such as load shocks and pH fluctuations). Therefore, isolating and screening new strains with high degradation capacity and good environmental adaptability is of great significance for promoting the development of biological remediation technologies for acrylonitrile pollution.

[0005] Currently reported acrylonitrile-degrading bacteria are limited in species and are mostly aerobic strains. Therefore, a facultative Rhodococcus ZQ-1 and its strains that degrade acrylonitrile in both aerobic and anaerobic systems were isolated and screened. These strains exhibit high degradation efficiency, can adapt to high concentrations, and have high survival rates under both aerobic and anaerobic conditions, making them suitable for a wide range of applications. Summary of the Invention

[0006] To address the problems existing in the prior art, the purpose of this invention is to design and provide a technical solution for facultative Rhodococcus ZQ-1 and its application in the degradation of organic pollutants in aerobic and anaerobic systems.

[0007] The present invention is implemented using the following technical solutions: The first aspect of the present invention provides a erythropoietinid ( Rhodococcussp.)ZQ-1, deposited at the China Center for Type Culture Collection, accession number CCTCC NO: M 2026457.

[0008] The Rhodococcus ZQ-1 strain described in this invention was obtained by collecting activated sludge from a wastewater treatment plant of a petrochemical enterprise, followed by separation and purification. Its 16S rDNA has the Genebank accession number PZ136199. The colony characteristics of this strain are as follows: the bacteria are rod-shaped, measuring (0.5~0.8) μm × (0.75~1.5) μm, without spores or flagella; the colonies are light pink, round, opaque, smooth, moist, and easily picked up; the bacterial growth follows a streak; and it is Gram-positive.

[0009] The second aspect of this invention provides the application of Rhodococcus ZQ-1 in the degradation of organic pollutants in aerobic and anaerobic systems.

[0010] Furthermore, the organic pollutants include one or more of acrylonitrile, butadiene, styrene, benzene, succinic acid, pyrazole, and 3-cyanopyridine.

[0011] The third aspect of the present invention provides a method for degrading organic pollutants in aerobic and anaerobic systems using the aforementioned Rhodococcus ZQ-1, wherein Rhodococcus ZQ-1 is added to an inorganic salt culture medium containing organic pollutants to carry out the degradation reaction.

[0012] Furthermore, the degradation reaction conditions are: pH = 5-9; the initial concentration of the organic pollutant in the inorganic salt culture medium is 40-250 mg / L.

[0013] The organic pollutants described in this invention can be completely degraded at medium to high concentrations (400-2000 mg / L).

[0014] Furthermore, the Rhodococcus ZQ-1 is added in the form of a bacterial suspension.

[0015] Furthermore, the method for preparing the bacterial suspension includes the following steps: S.1 Rhodococcus ZQ-1 was activated and inoculated onto R2A solid medium and cultured at 30℃ for 24–36 h to obtain slant cells; S.2 Pick an inoculation loop of colonies from the slant culture and inoculate it into an inorganic salt medium. Add acrylonitrile at an initial concentration of 165 mg / L and incubate at 30 °C and 160 r / min for 24–36 h to obtain a bacterial suspension.

[0016] Furthermore, the R2A solid culture medium comprises: 0.50 g / L yeast extract, 0.50 g / L soluble starch, 0.05 g / L MgSO4·7H2O, 0.50 g / L peptone, 0.50 g / L glucose, 0.30 g / L sodium pyruvate, 0.45 g / L K2HPO4, 20 g / L agar, and deionized water as the solvent.

[0017] Furthermore, the inorganic salt culture medium comprises: Na2HPO4 4.5 g / L, KH2PO4 1.0 g / L, (NH4)2SO4 2.5 g / L, MgSO4·7H2O 0.2 g / L, CaCl2 0.023 g / L, trace element stock solution 1 mL / L, pH 7.0, and deionized water as the solvent.

[0018] Furthermore, the trace element mother liquor comprises 1.0 g / L FeSO4·7H2O, 0.02 g / L CuSO4·5H2O, 0.014 g / L H3BO3, 0.10 g / L MnSO4·4H2O, 0.10 g / L ZnSO4·7H2O, 0.02 g / L Na2MoO4·2H2O, and 0.02 g / L CoCl2·6H2O, with deionized water as the solvent.

[0019] The fourth aspect of the present invention provides an organic pollutant degrading bacterium containing the aforementioned Rhodococcus ZQ-1.

[0020] The fifth aspect of this invention provides the application of organic pollutant degrading bacteria in the degradation of organic pollutants in aerobic and anaerobic systems.

[0021] Furthermore, the organic pollutants mentioned in this application include one or more of acrylonitrile, butadiene, styrene, benzene, succinic acid, pyrazole, and 3-cyanopyridine.

[0022] The present invention has the following beneficial effects: (1) This invention provides a highly efficient acrylonitrile-degrading bacterium—Rhodococcus ( Rhodococcus ZQ-1, a non-spore-forming, non-motile Gram-positive bacterium, can grow under conditions where acrylonitrile is the sole carbon and energy source, and efficiently degrades this substrate. This strain can also be used in aerobic and anaerobic systems. Furthermore, Rhodococcus (sp.) Rhodococcus sp.)ZQ-1 also has a certain degradation effect on butadiene and other organic pollutants.

[0023] (2) The Rhodococcus provided by this invention ( Rhodococcussp.)ZQ-1 exhibits good degradation performance, effectively degrading acrylonitrile at initial concentrations as high as 165 mg / L even with low initial bacterial counts.

[0024] (3) The Rhodococcus provided by this invention ( Rhodococcus sp.) ZQ-1 has a wide optimal growth temperature and pH range, with a minimum initial bacterial count (expressed as OD). 600 (Calculated) as OD 600 At a pH of 0.1, acrylonitrile can be degraded well within a pH range of 5.0 to 9.0, with a degradation rate of over 90%.

[0025] (4) The Rhodococcus provided by this invention ( Rhodococcus When sp.)ZQ-1 is used in aerobic and anaerobic systems to degrade organic pollutants, it is simple to operate, stable in operation, low in cost, and has mild reaction conditions, making it environmentally friendly. Attached Figure Description

[0026] Figure 1 Rhodococcus ( Rhodococcus Transmission electron micrograph of sp.)ZQ-1; Figure 2 Rhodococcus ( Rhodococcus Phylogenetic tree of sp.)ZQ-1; Figure 3 Rhodococcus ( Rhodococcus The broad substrate utilization of sp.) ZQ-1 and its growth curves under different oxygen conditions. Figure 3 In the figure, 'a' represents the bacterial growth curve under aerobic conditions. Figure 3 b in the text represents Rhodococcus ( Rhodococcus Broad spectrum analysis of sp.)ZQ-1; Figure 3 In the figure, 'c' represents the bacterial cell growth curve under anaerobic conditions. Figure 4 Rhodococcus ( Rhodococcus Degradation, growth, and CO2 generation characteristics of sp.) ZQ-1 under different initial acrylonitrile concentrations and aerobic / anaerobic conditions. Figure 4 In the figure, 'a' represents the removal rate of Rhodococcus ZQ-1 from different initial acrylonitrile concentrations in an aerobic system. Figure 4 In the diagram, b represents the growth of the bacterial strain under aerobic conditions. Figure 4 In this context, 'c' represents the CO2 production rate under aerobic conditions. Figure 4 In this context, d represents the acrylonitrile removal rate under anaerobic conditions. Figure 4 In the diagram, 'e' represents the growth of the bacterial strain in an anaerobic system. Figure 4 In this context, f represents the CO2 production rate under anaerobic conditions. Figure 5 The initial inoculum size for Rhodococcus ( under aerobic and anaerobic conditions) Rhodococcus The effect of acrylonitrile removal rate, strain growth, and CO2 production on sp.) ZQ-1 is shown in the figure. Figure 5 In the figure, 'a' represents the removal rate of Rhodococcus ZQ-1 by different initial bacterial counts in an aerobic system. Figure 5 In this context, 'b' represents the growth of the strain in an aerobic system. Figure 5 In the figure, 'c' represents the line graph showing the effect of CO2 production on the aerobic system. Figure 5 In this context, d represents the anaerobic system removal rate; Figure 5 In this context, 'e' represents the growth of anaerobic bacterial strains. Figure 5 In the figure, f represents the line graph showing the effect of CO2 production in the anaerobic system. Figure 6 pH for Rhodococcus ( Rhodococcus The effect of sp.)ZQ-1 on aerobic and anaerobic conditions on acrylonitrile degradation, strain growth, and CO2 generation. Figure 6 In this context, 'a' represents the removal rate of Rhodococcus ZQ-1 at different pH values ​​in an aerobic system. Figure 6 In this context, 'b' represents the growth of the strain in an aerobic system. Figure 6 In the bar chart, 'c' represents the effect of CO2 production on the aerobic system. Figure 6 In this context, d represents the removal rate of Rhodococcus ZQ-1 by different pH values ​​in the anaerobic system; Figure 6 In this context, 'e' represents the growth of anaerobic bacterial strains. Figure 6 In the bar chart, f represents the effect of CO2 production in the anaerobic system. Figure 7 For medium to high concentrations of pollutants to affect Rhodococcus ( Rhodococcus Effect of ZQ-1 on acrylonitrile degradation (sp.) diagram, Figure 7 In this context, 'a' represents the removal rate of the aerobic system. Figure 7 In this context, b represents the removal rate of the anaerobic system. Detailed Implementation

[0027] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other. Unless otherwise specified, the methods used in the embodiments of the present invention are conventional methods, and the reagents used are commercially available.

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below are generally only some, not all, of the embodiments of the present invention. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0029] The inorganic salt culture medium used in the following implementation has the following composition: Na₂HPO₄ 4.5 g / L, KH₂PO₄ 1.0 g / L, (NH₄)₂SO₄ 2.5 g / L, MgSO₄·7H₂O 0.2 g / L, CaCl₂ 0.023 g / L, and trace element stock solution 1 mL / L, pH 7.0, solvent: deionized water; the trace element stock solution has the following composition: FeSO₄·7H₂O 1.0 g / L, CuSO₄·5H₂O 0.02 g / L, H₃BO₃ 0.014 g / L, MnSO₄·4H₂O 0.10 g / L, ZnSO₄·7H₂O 0.10 g / L, Na₂MoO₄·2H₂O 0.02 g / L, CoCl₂·6H₂O 0.02 g / L. g / L, solvent is deionized water.

[0030] Example 1: Rhodococcus ( Rhodococcus Isolation, purification and identification of sp.) ZQ-1 (1) Rhodococcus ( Rhodococcus Isolation and purification of sp.) ZQ-1 Activated sludge was collected from a wastewater treatment plant of a petrochemical company in Zhejiang Province. After settling for 2 hours, the supernatant and suspended impurities were removed, leaving fine sludge particles. The lower sludge after settling for 2 hours was mixed with inorganic salt culture medium at a ratio of 1:2 (v / v). Then, 1.5 L of the mixture was introduced into a 2 L sludge acclimatization tank, and acclimatization was carried out at room temperature (25℃) with acrylonitrile as the sole carbon and energy source in the entire system.

[0031] During the sludge acclimatization experiment, the acclimatization tank was stably aerated. After aeration was stopped each day, the tank was allowed to stand for 30 minutes, and the pH of the upper layer of liquid was measured and maintained at approximately 7.0. Half of the upper culture medium was poured out daily and replaced with fresh inorganic salt medium. After acrylonitrile was completely degraded each day, substrate was added again to restore the concentration to 165 mg / L. After one month, 10 mL of the sludge-water mixture was taken from the acclimatization tank and added to a shake flask containing 50 mL of sterilized inorganic salt medium. It was found that the acclimatized sludge could stably degrade 165 mg / L of acrylonitrile daily in the shake flask (shake flask experimental conditions: 30℃, 160 r / min), thus obtaining the acclimatized sample.

[0032] Five mL of the acclimated sample from the shake flask was transferred to other shake flasks for further performance testing. Acrylonitrile with an initial concentration of 165 mg / L was added, and the samples were incubated at 30℃ and 160 r / min. After 24 h, the substrate concentration was measured, revealing that the transferred acclimated sample could stably degrade 95% or more of acrylonitrile within 48 h in the shake flask. This sludge sample was then further transferred and enriched into shake flasks containing 50 mL of inorganic salt medium, and then acrylonitrile with an initial concentration of 165 mg / L was added, resulting in six subcultures (5 mL for the first three subcultures, 2 mL for the fourth, and 1 mL for the last two). The bacterial culture samples after six subcultures were then processed according to a 10... -1 ~10 -9 After multiple dilution, the bacteria were plated and incubated in a 30°C incubator for 2–3 days. Single colonies were picked from the plates and streaked to separate them, thus obtaining pure colonies.

[0033] (2) Rhodococcus ( Rhodococcus Identification of sp.)ZQ-1 refer to Figure 1 Rhodococcus ( Rhodococcus The morphological characteristics of strain ZQ-1 are as follows: the bacteria are rod-shaped, measuring (0.5~0.8) μm × (0.75~1.5) μm, non-spore-forming, and non-flagellated; the colonies are light pink, round, opaque, smooth, moist, and easily picked up, with the bacterial growth following the streaks. Furthermore, the physiological and biochemical characteristics of strain ZQ-1 are: facultatively asexual, and Gram-positive.

[0034] The obtained strain was entrusted to Shanghai Sangon Biotech Co., Ltd. for PCR amplification and sequencing. The 16S rDNA sequencing results are shown in SEQ ID NO.1, and the Genebank accession number is PZ136199.

[0035] The sequencing results were uploaded to the Ezbiocloud.net website and compared with the standard strains on the website. Then, using MEGA 9.05 software, a phylogenetic tree was constructed using the Neighbor-Joining method. Finally, the BootHWZrap method (repeated 1000 times) was used for evaluation. The constructed phylogenetic tree is shown below. Figure 2 Thus, the strain was identified as Rhodococcus sp., named Rhodococcus ( Rhodococcus sp.)ZQ-1, deposited at the China Center for Type Culture Collection, date of deposit: March 16, 2026, accession number: CCTCC NO: M 2026457.

[0036] Example 2: Rhodococcus ( Rhodococcus Large-scale culture of sp.)ZQ-1 (1) Slant culture: Rhodococcus ( Rhodococcus ZQ-1 sp. was inoculated into R2A solid slant medium and cultured at 30℃ for 24 h to obtain slant cells. The composition of the R2A solid medium is as follows: yeast extract 0.50 g / L, soluble starch 0.50 g / L, MgSO4·7H2O 0.05 g / L, peptone 0.50 g / L, glucose 0.50 g / L, sodium pyruvate 0.30 g / L, K2HPO4·3H2O 0.45 g / L, agar 20 g / L, pH approximately 7.2, and deionized water as the solvent. (2) Preparation of bacterial suspension: A loopful of colonies was picked from the slant in step (1) and inoculated into an inorganic salt culture medium. Acrylonitrile with an initial concentration of 165 mg / L was added, and the medium was cultured at 30℃ and 160 r / min for 24 h to obtain a bacterial suspension. The inorganic salt culture medium consisted of: Na2HPO4 4.5 g / L, KH2PO4 1.0 g / L, (NH4)2SO4 2.5 g / L, MgSO4·7H2O 0.2 g / L, CaCl2 0.023 g / L, and trace element stock solution 1 mL / L. The pH was 7.0, and the solvent was deionized water. The trace element stock solution consisted of: FeSO4·7H2O 1.0 g / L, CuSO4·5H2O 0.02 g / L, H3BO3 0.014 g / L, and MnSO4·4H2O 0.10 g / L. The concentrations of the following ingredients were: ZnSO4·7H2O 0.10 g / L, Na2MoO4·2H2O 0.02 g / L, and CoCl2·6H2O 0.02 g / L. The solvent was deionized water.

[0037] Example 3: Rhodococcus ( Rhodococcus Degradation characteristics of ZQ-1 for acrylonitrile Acrylonitrile as a base for Rhodococcus ( Rhodococcus The only carbon and energy source for sp. ZQ-1 is the bacterial suspension prepared according to the method in Example 2, which is then inoculated into 50 mL of inorganic salt culture medium to achieve an initial bacterial concentration (expressed as OD). 600 The initial concentration of acrylonitrile was 0.01 mg / L, and then 165 mg / L of acrylonitrile was added. The anaerobic system was subjected to nitrogen blowing in a sterile environment for 30 min. It was then cultured in a shaker at 30℃ and 160 r / min. Samples were taken every 3 h to determine the acrylonitrile degradation rate. Simultaneously, a portion of the bacterial culture was extracted using a 5 mL syringe to determine the bacterial cell OD value. The results are shown below. Figure 3 During the experiment, three parallel samples and one blank control group without inoculation were designed. As time progressed, the bacterial concentration gradually increased, reaching its maximum at 9 hours (approximately OD₀). 600 =0.303, OD in anaerobic system 600 =0.262, acrylonitrile degradation rate reaches 99%. The growth status of the strains in its aerobic and anaerobic systems is as follows: Figure 3 a and Figure 3 As shown in c. This embodiment describes Rhodococcus (…). Rhodococcus sp.)ZQ-1 can use acrylonitrile as the sole carbon and energy source for growth and reproduction, and has a stable and efficient ability to degrade acrylonitrile.

[0038] Example 4: Rhodococcus ( Rhodococcus sp.)ZQ-1 expanded culture The only difference between this embodiment and Embodiment 2 is the following; the other identical parts will not be described again here.

[0039] (1) Slant culture: The slant culture time was 36 h, and the agar content in R2A solid medium was 20 g / L; (2) Preparation of bacterial suspension: The culture time is 36 h.

[0040] Example 5: Rhodococcus ( Rhodococcus ZQ-1's degradation ability on different carbon source substrates Take the bacterial suspension prepared by the method in Example 2 and inoculate it into 50 mL of inorganic salt culture medium to achieve an initial bacterial concentration (expressed as OD). 600 The total amount was 0.1, and then acrylonitrile, styrene, butadiene, benzene, succinic acid, pyrazole, and 3-cyanopyridine were added. The mixture was incubated in a shaker at 30℃ and 160 r / min. The substrate degradation rate was measured at 12 h and 24 h, respectively. The results are shown in the table below. Figure 3 As shown in b. Rhodococcus was found ( Rhodococcussp. ZQ-1 exhibited varying degrees of degradation of acrylonitrile, styrene, butadiene, benzene, succinic acid, pyrazole, and 3-cyanopyridine. Detailed data are shown in Table 1. The removal rates within 12 hours ranged from approximately 0.84% ​​to 53.08%, and after 24 hours, the removal rates for each pollutant were 57.76%, 6.68%, 60.69%, 4.69%, 6.24%, and 8.82%, respectively. The degradation rates of pollutants with different chemical structures and biotoxicities varied considerably, generally exhibiting the following order: acrylonitrile > succinic acid > styrene > butadiene > benzene > 3-cyanopyridine > pyrazole. This demonstrates that strain ZQ-1 can degrade and grow on these six pollutants.

[0041] Table 1. Rhodococcus ( Rhodococcus ZQ-1's degradation capabilities for different carbon source substrates .

[0042] Example 6: Effect of substrate concentration on Rhodococcus ( Rhodococcus Effect of sp.)ZQ-1 on the degradation of acrylonitrile Take the bacterial suspension prepared by the method in Example 2 and inoculate it into 50 mL of inorganic salt culture medium to achieve an initial bacterial concentration (expressed as OD). 600 The initial concentration of acrylonitrile was 0.1 mg / L, followed by the addition of acrylonitrile at initial concentrations of 40, 80, 165, 200, and 250 mg / L. The anaerobic system was subjected to nitrogen purging in a sterile environment for 30 min. The mixture was then incubated in a shaker at 30℃ and 160 r / min, with periodic sampling to determine the acrylonitrile concentration and the concentration of Rhodococcus (…). Rhodococcus sp.)ZQ-1 bacterial culture OD 600 Values, results are shown below Figure 4 As shown. In the experiment, three parallel samples and one blank control group without inoculation were designed. Through observation... Figure 4 As shown in a, the time required for the complete degradation of different concentrations of acrylonitrile in the aerobic system is 2 h, 3 h, 5 h, 6 h, and 7 h, respectively. Figure 4 OD in diagram b 600 The concentrations of acrylonitrile increased from an initial 0.1 to 0.14, 0.19, 0.26, 0.33, and 0.34, respectively. Even at a high acrylonitrile concentration of 250 mg / L, the degradation rate of strain ZQ-1 did not decrease significantly, while the biomass continued to increase, demonstrating that strain ZQ-1 can degrade even higher concentrations of acrylonitrile. The CO2 production was as follows: Figure 4 As shown in c. Anaerobic system Figure 4 The values ​​in 'd' show the time required for complete degradation of different concentrations of acrylonitrile: 1 h, 3 h, 4 h, 6 h, and 7 h. Figure 4 OD in China 600The concentrations increased from an initial 0.1 to 0.15, 0.18, 0.292, 0.62, and 0.302, respectively. It was also found that the anaerobic system degraded faster at lower concentrations, with CO2 production as... Figure 4 As shown in f.

[0043] Example 7: Effects of different initial bacterial loads on Rhodococcus ( Rhodococcus Effect of sp.)ZQ-1 on the degradation of acrylonitrile Take the bacterial suspension prepared by the method in Example 2 and inoculate it into 50 mL of inorganic salt culture medium to achieve an initial bacterial concentration (expressed as OD). 600 The acrylonitrile (calculated as a percentage of total nitrogen) was divided into concentrations of 0.05, 0.1, 0.15, 0.20, 0.25, and 0.3, and then acrylonitrile with an initial concentration of 165 mg / L was added. The anaerobic system was subjected to nitrogen blowing in a sterile environment for 30 min. The mixture was then incubated in a shaker at 30 ℃ and 160 r / min, with periodic sampling to determine the concentration of acrylonitrile and Rhodococcus (Rhodococcus) in the reaction solution. Rhodococcus sp.)ZQ-1 bacterial culture OD 600 Values, results are shown below Figure 5 As shown. In the experiment, three parallel samples and one blank control group without inoculation were designed. Through observation... Figure 5 From a, we can see that in the aerobic system, the initial OD 600 When the concentrations are 0.25 and 0.3, the degradation times are 4 h and 3 h, respectively. The growth status of the strain in the aerobic system is as follows: Figure 5 As shown in b, the CO2 production is as follows Figure 5 As shown in c. OD in an anaerobic system 600 The degradation time for a concentration of 0.25 is 2 hours. Figure 5 For other bacterial concentrations, the complete degradation time is around 7 hours. Therefore, as the initial bacterial count increases, the average acrylonitrile removal rate is faster, and the carbon dioxide production is greater. The growth status of the strains in the anaerobic system is as follows: Figure 5 As shown in e, the CO2 production is as follows Figure 5 As shown in f.

[0044] Example 8: The effect of pH value on Rhodococcus ( Rhodococcus Effect of sp.)ZQ-1 on the degradation of acrylonitrile The inorganic salt culture medium was adjusted to different pH values ​​(specifically 5.0, 6.0, 7.0, 8.0, and 9.0) using 1 mol / L NaOH or 1 mol / L H2SO4 aqueous solution. The bacterial suspension prepared in Example 2 was inoculated into 50 mL of inorganic salt culture medium to achieve an initial bacterial concentration (expressed as OD200). 600The initial concentration of acrylonitrile was 0.1 mg / L, and then 165 mg / L of acrylonitrile was added. The mixture was then incubated in a shaker at 30 °C and 160 r / min. Samples were taken periodically to determine the acrylonitrile degradation rate and OD of the bacterial culture. 600 Values ​​and CO2 values; results for the aerobic system are shown in [link to results]. Figure 6 a, Figure 6 b, Figure 6 As shown in c, the results for the anaerobic system are shown in [the diagram]. Figure 6 d, Figure 6 e Figure 6 As shown in f. During the experiment, three parallel samples and one blank control group without inoculation were designed. Rhodococcus ( ) [The experiment was conducted] within a pH range of 5–8. Rhodococcus ZQ-1 sp. showed a degradation rate of over 60% for acrylonitrile, especially at pH 7 and 8, for Rhodococcus (sp.) Rhodococcus ZQ-1 sp. showed the best degradation effect on acrylonitrile, with a degradation rate of over 99%, while also inhibiting Rhodococcus (sp.) Rhodococcus The growth rate and CO2 production of sp.) ZQ-1 showed a consistent trend with the acrylonitrile degradation rate. Experiments revealed that... Figure 6 The optimal pH for a in this context is 7. Figure 6 The optimal pH for d is 8.

[0045] Example 9: Effects of medium- and high concentrations of pollutants on Rhodococcus ( Rhodococcus Effect of sp.)ZQ-1 on the degradation of acrylonitrile Take the bacterial suspension prepared by the method in Example 2 and inoculate it into 50 mL of inorganic salt culture medium to achieve an initial bacterial concentration (expressed as OD). 600 The initial concentration of acrylonitrile was 0.1 mg / L, and then initial concentrations of 400, 800, 1200, 1600, and 2000 mg / L were added respectively. The mixture was incubated in a shaker at 30 ℃ and 160 r / min. Samples were taken periodically to determine the acrylonitrile degradation rate in the reaction solution. Two systems were set up, with three parallel samples and one blank control group without inoculation. The results are as follows: Figure 7 As shown. Figure 7 'a' represents the removal rate of the aerobic system, derived from... Figure 7 As can be seen from 'a', acrylonitrile at concentrations of 400, 800, 1200, 1600, and 2000 mg / L achieved degradation rates of over 95% at 12, 20, 24, 40, and 48 hours, respectively. Figure 7 b represents the removal rate of the anaerobic system, derived from... Figure 7As shown in b, acrylonitrile concentrations of 400, 800, 1200, 1600, and 2000 mg / L achieved removal rates of over 95% at 10, 24, 28, 44, and 48 h, respectively. Strain ZQ-1 demonstrated highly efficient degradation capabilities for acrylonitrile at concentrations ranging from 400 to 2000 mg / L, with the final degradation rate consistently exceeding 95% for each concentration in both systems.

Claims

1. A type of Rhodococcus ( Rhodococcus sp.)ZQ-1, deposited at the China Center for Type Culture Collection, accession number CCTCC NO: M 2026457.

2. The application of Rhodococcus ZQ-1 as described in claim 1 in the degradation of organic pollutants in aerobic and anaerobic systems; wherein the organic pollutant is one or more of acrylonitrile, butadiene, styrene, benzene, succinic acid, pyrazole, and 3-cyanopyridine.

3. The method for degrading organic pollutants using Rhodococcus ZQ-1 as described in claim 1, characterized in that, Rhodococcus ZQ-1 was added to an inorganic salt culture medium containing organic pollutants for degradation reaction; the organic pollutants were one or more of acrylonitrile, butadiene, styrene, benzene, succinic acid, pyrazole, and 3-cyanopyridine.

4. The method as described in claim 3, characterized in that, The degradation reaction conditions are: pH = 5-9; the initial concentration of the organic pollutant in the inorganic salt culture medium is 40-250 mg / L.

5. The method as described in claim 3, characterized in that, The Rhodococcus ZQ-1 was added in the form of a bacterial suspension.

6. The method as described in claim 5, characterized in that, The method for preparing the bacterial suspension includes the following steps: S.1 Rhodococcus ZQ-1 was activated and inoculated onto R2A solid medium and cultured at 30℃ for 24–36 h to obtain slant cells; S.2 Pick an inoculation loop of colonies from the slant culture and inoculate it into an inorganic salt medium. Add acrylonitrile at an initial concentration of 165 mg / L and incubate at 30℃ and 160 r / min for 24–36 h to obtain a bacterial suspension.

Images