Paracoccus capable of efficiently degrading DMF (Dimethyl Formamide) and application

Abstract

The invention discloses paracoccus capable of efficiently degrading DMF (Dimethyl Formamide) and application, and relates to the technical field of industrial wastewater treatment. The strain is named as paracoccus by taxonomy, the Latin name is Paracoccus sp., and the independent number is HZLQY-2024-A0101. The strain is preserved in the China General Microbiological Culture Collection Center (CGMCC), and the preservation number is CGMCC NO: 32830. The invention provides a bacterial culture containing the paracoccus, such as a bacterial liquid or a bacterial agent, which can be applied to the biodegradation treatment of DMF (Dimethyl Formamide) in industrial wastewater. The strain separated by the invention has relatively high DMF (Dimethyl Formamide) tolerance and relatively good DMF degradation capability, and efficient ammoniation and mineralization of DMF are realized. Under the condition of not additionally adding a carbon source and a nitrogen source, the strain separated by the invention can degrade more than 99% of 5000mg / L DMF (Dimethyl Formamide), and is suitable for wastewater with wide pH and temperature ranges.

Description

Technical Field

[0001] The invention relates to the technical field of industrial wastewater treatment, and in particular to a Paracoccus strain capable of efficiently degrading DMF and an application thereof. Background Art

[0002] N,N-Dimethylformamide (DMF) is an important organic solvent widely used in the chemical, pharmaceutical, electronics, synthetic fiber, coatings, pesticide, and other industries. Due to its excellent solubility and stability, global annual production exceeds 500,000 tons. However, the frequent use of DMF leads to its accumulation in industrial wastewater, exhaust gas, and soil, posing serious environmental and health risks. First, it is difficult to degrade naturally in the environment, with a half-life of several weeks to months, and tends to remain in soil and water for long periods of time. Second, it can enter the human body through skin contact, inhalation, or ingestion. Long-term exposure can cause liver damage, gastrointestinal diseases, nervous system damage, and even cancer. Therefore, the treatment and reduction of wastewater containing DMF is a major issue in environmental governance.

[0003] Currently, microbial degradation is considered the most promising method for DMF treatment, but reported DMF-degrading bacteria still suffer from low degradation efficiency and difficulties in engineering applications. Most strains (such as Pseudomonas putida and Bacillus subtilis) show a degradation rate of less than 50% within 72 hours at 1000 mg / L DMF, far below the requirement for industrial wastewater treatment (>90%). Furthermore, while some strains (such as Paracoccus sp. strain DMF-3) can degrade DMF, this is only effective at low concentrations (<300 mg / L), with growth being inhibited at higher concentrations (>1000 mg / L).

[0004] Therefore, developing a strain that can efficiently degrade DMF and applying it to actual wastewater treatment has important application value for environmental water management. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a Paracoccus that can efficiently degrade DMF and apply it to the degradation of DMF in wastewater. The Paracoccus isolated by the present invention can efficiently degrade DMF into NH3-N. Subsequently, combined with the conventional "nitrification-denitrification" process, the denitrification of DMF wastewater can be achieved, and it has been applied in actual wastewater treatment.

[0006] The strain was isolated from the bottom mud of Chaohu Lake. The following method was used for isolation: 10mL of fresh bottom mud taken from Chaohu Lake was inoculated into a conical flask containing an inorganic salt culture medium (DMF concentration was controlled at 1000mg / L), and placed in a shaking incubator at 30°C and 100r / min for 1 week. During this period, samples were taken every other day to detect the TN and NH3-N values in the system. After culturing for 1 week, it was transferred to a fresh inorganic salt culture medium (DMF concentration was controlled at 2000mg / L) at a 12% inoculation rate, and the TN and NH3-N values in the system were monitored, and the culture was continued for 1 week. The transfer was repeated 4 times, and the DMF concentration was gradually increased to 4000mg / L. Take 1mL of the bacterial solution from the culture system where the bacteria are growing well, and incubate at 10 -2 to 10 -8 The bacterial solution was diluted and spread onto an inorganic salt medium containing 1000 mg / L DMF, and cultured at 30°C for 5 days. A single colony was picked and transferred to a DMF selective medium, cultured at 30°C with shaking for 5 days, and then streaked for purification and isolation to obtain the strain.

[0007] The isolated strain was sequenced by 16S rDNA, compared in the database, and a phylogenetic tree was constructed. It was finally identified as Paracoccus sp. and numbered HZLQY-2024-A0101. On November 28, 2024, it was sent to the General Microbiology Center of the China Culture Collection of Microorganisms for preservation, and obtained the preservation number CGMCCNO: 32830. The address of the preservation unit is No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, Postal Code 100101.

[0008] The present invention also discloses a specific application of the Paracoccus. A bacterial culture containing the Paracoccus, such as a bacterial liquid or a bacterial agent, can be used in the biodegradation treatment of DMF in industrial wastewater.

[0009] Compared with the prior art, the present invention has the following beneficial effects:

[0010] (1) The strain has high tolerance to DMF and good DMF degradation ability, achieving efficient ammonia and mineralization of DMF.

[0011] (2) Without adding additional carbon and nitrogen sources, the strain can degrade more than 99% of 5000 mg / LDMF and is adaptable to wastewater with a wide pH (5.0-9.0) and temperature (15-40°C) range. DETAILED DESCRIPTION

[0012] Example 1 Domestication, Isolation and Identification of Strain

[0013] 1. Culture medium and culture conditions

[0014] Inorganic salt medium: CH3COONa 3g / L; (NH4)2SO4 2g / L; NaCl 25g / L; FeSO4·7H2O 0.01g / L; MgSO4·7H2O 0.5g / L; MnSO4·4H2O 0.05g / L; KCl 0.5g / L; KH2PO4 1g / L. DMF was added as a nitrogen and carbon source.

[0015] DMF selective medium: Add 1 mL of DMSO (dimethyl sulfoxide) and 1 mL of DMF (N,N-dimethylformamide) to 100 mL of LB medium. LB medium components include: 0.2 g / L oxoid peptone, 0.2 g / L oxoid yeast extract, and 5 g / L glucose.

[0016] Culture conditions: 28°C-32°C (optimal temperature 30°C), pH 6.5-8.5 (optimal pH 7.5), salinity about 3%.

[0017] 2. Strain domestication

[0018] 10mL of fresh sediment from Chaohu Lake was inoculated into a flask containing an inorganic salt culture medium (controlled at a DMF concentration of 1000mg / L) and incubated in a shaking incubator at 30°C and 100rpm for one week. Samples were taken every other day to test the TN and NH3-N values in the system. After one week of incubation, the inoculum was transferred to a fresh inorganic salt culture medium (controlled at a DMF concentration of 2000mg / L) at a 12% inoculum volume. TN and NH3-N values were monitored and incubated for another week. Four more transfers were performed, gradually increasing the DMF concentration to 4000mg / L.

[0019] 3. Bacteria separation:

[0020] Take 1mL of bacterial solution from a culture system with good bacterial growth, and -2 to 10 -8 The bacterial solution was diluted and spread onto an inorganic salt culture medium containing 1000 mg / L DMF, and cultured at 30°C for 5 days.

[0021] A single colony was picked and placed in DMF selective medium, cultured at 30°C with shaking for 5 days, and then streaked for purification and isolation to obtain the strain.

[0022] 4. Identification of bacterial species:

[0023] The isolated strain was sequenced by 16S rDNA, compared in the database, and a phylogenetic tree was constructed. It was finally identified as Paracoccus sp. and numbered HZLQY-2024-A0101. On November 28, 2024, it was sent to the General Microbiology Center of the China Culture Collection of Microorganisms for preservation, and obtained the preservation number CGMCCNO: 32830. The address of the preservation unit is No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, Postal Code 100101.

[0024] 5. Characteristics of strains:

[0025] Degradation performance: Under the conditions of initial DMF concentration of 5000 mg / L, 30℃, and pH 7.0, the 5-day degradation rate is ≥99%.

[0026] Degradation pathway: formamide → formic acid → CO2 + H2O

[0027] Environmental adaptability: pH tolerance range is 5.0-9.0 (optimum 7.0-8.0), temperature tolerance range is 15-40℃ (optimum 25-35℃).

[0028] Example 2 Industrial DMF Wastewater Treatment

[0029] The strain was cultured at 1×10 8 CFU / mL was inoculated into pharmaceutical wastewater containing 5000mg / L of DMF. Urea and phosphate were then added to achieve a C:N:P molar ratio of 190:5:1 for biofermentation. The fermentation system was initially fed intermittently at a low load, followed by continuous, high-load inflow. During the fermentation process, COD and DMF levels were regularly monitored. After five days of treatment, the wastewater showed a COD removal rate of 75.3%, a DMF removal rate of 99%, and a total nitrogen removal rate of over 70%.

[0030] Example 3 Immobilized Bioreactor Treatment of DMF Wastewater

[0031] The bacterial strain was embedded in sodium alginate and DMF wastewater was continuously treated (flow rate 10 L / h), with a removal rate stable at over 85%.

[0032] The above content is merely an example and explanation of the concept of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A strain of Paracoccus that can efficiently degrade DMF, taxonomically named Paracoccus, Latin name Paracoccus sp., self-numbered HZLQY-2024-A0101, has been deposited in the General Microbiology Center of the China Culture Collection Administration of Microorganisms, with the deposit number CGMCC NO: 32830, the deposit date is November 28, 2024, and the depository address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences, Postal Code 100101.

2. A bacterial culture containing the Paracoccus according to claim 1.

3. The bacterial culture according to claim 2, wherein The bacterial culture is a bacterial liquid or a bacterial agent.

4. Use of the Paracoccus as claimed in claim 1, or the bacterial culture as claimed in claim 2 or 3, in treating DMF in industrial wastewater.

5. The use according to claim 4, characterized in that The strain was inoculated into wastewater containing DMF for DMF degradation treatment.

6. The use according to claim 4, characterized in that Sodium alginate was used to embed the bacterial strain for continuous treatment of DMF wastewater.