Paracoccus sp. and culture application thereof

[0028] Example 2 Screening and separation and purification

[0029] The method of gradually increasing the salt concentration in the culture solution was used to domesticate and cultivate the activated sludge taken from a petrochemical enterprise in Yueyang City, Hunan Province for treating the wastewater from the production of epichlorohydrin for 15 days.

[0030] The above-mentioned domesticated activated sludge is taken and preliminarily separated in the enriched medium by the method of dilution coating, thereby obtaining 15 colonies with good growth status and different characteristics. The used enrichment medium contains the main components: COD is 1000mg/L, calcium ion concentration is 1000mg/L, total salt content is 10000mg/L, and the agar content in the solid medium used is 2.0%.

[0031] Then, the obtained colonies are transferred by the method of plate streaking, and streaking is transferred to the screening medium for further separation and screening. The main components of the screening medium used are: COD of 1000 mg/L, calcium ion concentration of 4000 mg/L, total salt content of 25000 mg/L, and agar content of 2.0% in the solid medium used.

[0032] 10 pure strains were obtained from the above operation, one of which is Paracoccus ( Paracoccus sp. ) FSTB-2.

[0033] Example 3 Investigation of Salt Tolerance of Paracoccus FSTB-2

[0034] The culture method of Paracoccus FSTB-2 of the present invention includes: strain activation, liquid seed liquid culture, aeration culture, and the specific process is as follows:

[0035] (1) Strain activation: Paracoccus ( Paracoccus sp. ) FSTB-2 was inoculated into a plate containing FSTB solid medium, cultured at 35°C for 48 hours, and then stored in a refrigerator at 4°C for later use. The FSTB solid medium is: FeSO 4 • 7H 2 O 25mg/L, NH 4 NO 3 286mg/L, KCl 929mg/L, CaCl 2 2769mg/L, NaCl 21008mg/L, beef extract 5g/L, peptone 10g/L, agar 20g/L, pH 7.8.

[0036] (2) Liquid seed solution culture: prepare FSTB liquid culture medium, divide it into Erlenmeyer flasks, sterilize and cool to room temperature, use an inoculating loop to pick the activated strains from the plate in a sterile environment and inoculate them into Erlenmeyer flasks. Cultivate for 48 hours at 35°C. The FSTB liquid medium is: FeSO 4 • 7H 2 O 25mg/L, NH 4 NO 3 286mg/L, KCl 929mg/L, CaCl 2 2769mg/L, NaCl 21008mg/L, beef extract 5g/L, peptone 10g/L, pH 7.8.

[0037] (3) Aeration culture: a closed reactor is used for culture, the reactor and various appliances used need to be completely sterilized, and the air inlet and exhaust positions need to be installed with bacterial filtration devices, culture fluid, acid-base regulator and trace amount The element solutions need to be sterilized and then added in accordance with the aseptic operating procedures. The fermenter needs to be equipped with aeration devices, and can be used for water intake, acid adjustment, alkali adjustment, feeding and drainage and discharge operations. Put it in the reactor The sterilized FSTB liquid culture medium is inoculated with the liquid seed solution at a rate of 10% by volume. After the culture process is started, the pH value of the culture solution is controlled within 6.0-8.5 by the acid-base automatic control system during the culture process, and the culture is aerated After 72 hours, perform periodic feeding and discharging operations. The discharging is 25% of the reactor volume of the culture solution, and the feeding is 25% of the reactor volume of the FSTB liquid medium. It can also be supplemented by a sterile feeding device at the same time. Add a small amount of carbon source, nitrogen source and trace element substances, cultivate for 24 hours as a culture cycle, and then discharge a corresponding volume of culture solution according to the above ratio, thereby obtaining a concentrated bacterial solution product containing pure paracoccus.

[0038] Collect the above-mentioned concentrated bacteria solution, dilute it and spread it on a plate containing FSTB solid medium, count the grown colonies and calculate the percentage of colonies similar to FSTB-2. The similar percentage reaches more than 95%, which is deemed The paracoccus is a pure strain.

[0039] The paracoccus FSTB-2 obtained by the above cultivation is used to treat salty wastewater. This embodiment takes the pretreated salty wastewater of the epichlorohydrin production process as an example. The water quality of the treated salty wastewater is: the COD concentration is 800-2000mg/L, the salt content is 1wt%-8wt%, and the treatment temperature is 30%. -40°C. The treatment effect is shown in Table 2.

[0040] Table 2 Effect of Paracoccus FSTB-2 in the treatment of saline wastewater

[0041]

[0042] It can be seen from Table 2 that the salt content that Paracoccus FSTB-2 can tolerate is 1wt%-8wt%, can grow at a high temperature of 40℃, and can efficiently remove COD in salty wastewater.

[0043] The Paracoccus FSTB-2 of the present invention has very good adaptability and treatment effect to actual salt-containing wastewater, and has a strong COD degradation function. The pure strain can be used alone to treat salt-containing wastewater, or it can be separately amplified and cultured as an external Source functional microorganisms are added to the existing process flow, and the actual process conditions are optimized and adjusted in a targeted manner, so as to solve the problem of poor treatment effect and easy degradation of activated sludge in a high-salt environment. The use of salt-tolerant bacteria to treat high-salinity wastewater is less costly than physical and chemical methods, and direct application will produce more obvious economic and social benefits, which can provide technical support for the treatment of high-salt-related wastewater to meet the discharge standards.