2065438+0710127 October, the list of carcinogens published by the International Agency for Research on Cancer of the World Health Organization was preliminarily sorted out for reference. Phenol is in the list of three types of carcinogens.
Chinese name: Phenol English name: phenol alias: carbolic acid, phenol, hydroxybenzene chemical formula: C6H5OH molecular weight: 94. 1 1 CAS registration number: 108-95-2 EINECS registration number: 203-632-7 melting point: 43℃. Soluble in ethanol, ether, chloroform and glycerol. Density: 1.07 1g/mL(25℃). Appearance: colorless or white crystals with special smell. It turns pink in air and light. Flash point: 185℉/85℃ Application: chemical synthesis, oilfield industry, electroplating, solvent, medical safety Description: S26, S28, S45, S24/S25, S36/S37/S39 Hazard symbols: F (flammable), T (toxic) and C (toxic). R23/24/25, R48/20/2 1/22 Dangerous goods transport number: UN 282 1 6. 1/PG 2 Chemical properties: weak acidity, high toxicity, mutagenicity, reductive stability: stable prohibited compounds: strong oxidant, strong acid, strong alkali storage. Pay attention to leakage PSA: 20.23000logp:1.39220 refractive index: n20/D 1.54 18 customs code: 290711000 discovery history. Substitution reaction, redox reaction, condensation reaction, preparation method, sulfonation method, cumene method, chlorobenzene hydrolysis method, crude phenol refining method, benzene oxidation method, toluene oxidation method, matters needing attention, health hazards, first aid measures, fire protection measures, emergency treatment of leakage, operation and disposal storage, allowable limit, allowable limit in water, related experiments, phenol acidity, communication phenomenon, experimental conclusion, demonstration experiment, application. It was discovered that historical phenol was discovered in coal tar by German chemist Runge F in 1834, so it was also called carbolic acid. It was the British famous doctor Lester who first made phenol famous. Liszt found that most of the causes of postoperative death were suppurative infection of wounds. Occasionally, dilute phenol solution is sprayed on surgical instruments and doctors' hands, and as a result, the infection of patients is obviously reduced. This discovery makes phenol a powerful surgical disinfectant. Liszt is also known as the "father of surgical disinfection". Molecular structure Phenol molecules consist of a hydroxyl group directly attached to the benzene ring. Because of the stability of benzene ring, such structure will hardly be converted into ketone structure. The vibration structure of phenol is shown in the upper right figure. The oxygen atom of phenolic hydroxyl group is hybridized by sp2, providing a pair of lone electrons to form delocalization bonds with six carbon atoms of benzene ring. The large π bond strengthens the acidity of enol, and the electron pushing action of hydroxyl strengthens the polarity of O-H bond, so the hydrogen of hydroxyl in phenol can be ionized. Phenolate anion is shown in the right figure * * * Vibration structure: molar refractive index: 28. 13.
Molar volume (m3/mol): 87.8
Isotonic specific volume (90.2 k): 222.2
Surface tension (dyne/cm): 40.9
Polarization: 1 1. 15 Physical properties Relative vapor density (air = 1): 3.24 refractive index 1.54 18 saturated vapor pressure (kPa): 0.1. The logarithmic value of: 6. 13 octanol/is soluble in organic solvents such as ethanol, glycerol, chloroform and ether at room temperature, slightly soluble in water at room temperature, liquefied when mixed with about 8% water, miscible with water above 65℃ and almost insoluble in petroleum ether. Chemical properties can absorb moisture in the air and liquefy it. It has a special smell, and the extremely dilute solution has a sweet taste. Very corrosive. Strong chemical reaction ability. React with aldehyde and ketone to produce phenolic resin, bisphenol A and acetic anhydride; Salicylic acid reacts to form phenyl acetate and salicylate. Halogenation, hydrogenation, oxidation, alkylation, carboxylation, esterification, etherification and other reactions can also be carried out. Phenol is a solid at room temperature and cannot react with sodium smoothly. If phenol is heated and melted, and then sodium metal is added for the experiment, phenol can be easily reduced, and the color of phenol will change when heated, which will affect the experimental effect. Some people adopt the following methods to carry out experiments in teaching, which are simple to operate and have achieved satisfactory experimental results. Add 2-3 ml of anhydrous ether to the test tube, take a piece of metallic sodium the size of soybean grain, use filter paper to absorb kerosene on the surface, and put it into ether, which shows that sodium does not react with ether. Then add a small amount of phenol into the test tube and shake. At this time, it can be observed that sodium reacts quickly in the test tube and produces a lot of gas. The principle of this experiment is to dissolve phenol in ether, so that the reaction between phenol and sodium can proceed smoothly. Acid-base reaction Phenol is a kind of weakly acidic phenol, which can react with alkali: PhOH+NaOH→PhONa+H 2 O phenol Ka =1.28×10-10, and its acidity is between the two levels of ionization of carbonic acid, so phenol can't react with NaHCO 3: PHO ˉ+CO 2+H 2 Cause: Phenol precipitates due to low solubility. Color reaction phenol will turn purple when it meets ferric chloride solution, because phenol ions form colored complexes with Fe. 6 Hoh+FeCl 3 → H 3 [Fe (Oph) 6] (purple) +3HCl substitution reaction Electrophilic substituted phenols can produce electrophilic substitutions similar to benzene on the ring due to their benzene ring structure, such as nitration and halogenation. Compared with the corresponding reaction of benzene, the ring substitution of phenol is much easier than that of benzene. This is because hydroxyl group has the function of donating electrons, which increases the electron cloud density of benzene ring. It is worth noting that the electrophilic substitution of phenol always occurs in the ortho and para positions of hydroxyl groups. This is the * * nature of electron-donating groups such as hydroxyl groups. Substitution on Phenol Hydroxyl The hydrogen atom on Phenol Hydroxyl can be substituted by carbon-containing groups to form ethers or esters. Redox phenol turns pink in air for a long time because benzoquinone is formed: the oxidation product of phenol is usually p-benzoquinone. Br 2 can also be used as oxidant in this reaction. Condensation reaction Phenol and formaldehyde are condensed under the catalysis of acid or alkali to produce phenolic resin. Preparation method Phenol was first recovered from coal tar, and most of it is synthetic at present. By the mid-1960s, the technical route of producing phenol and acetone by cumene method had developed to account for half of the world's phenol production. At present, the phenol produced by this process has accounted for more than 90% of the world phenol output. Other production processes include toluene chlorination, chlorobenzene and sulfonation. There are two production methods in China: cumene method and sulfonation method. Because sulfonation consumes a lot of sulfuric acid and caustic soda, China will only keep a few sulfonation devices and gradually focus on cumene production. Sulfonation method takes benzene as raw material, sulfonates benzene sulfonic acid with sulfuric acid, neutralizes it with sulfurous acid, then melts it with caustic soda, and then sulfonates it and distills it under reduced pressure. Raw material consumption quota: pure benzene 1004kg/t, sulfuric acid (98%) 1284kg/t, sodium sulfite 1622kg/t, caustic soda (100%)1200kg. Phenol and acetone are obtained simultaneously. About 0.6t acetone is by-produced per ton of phenol. Raw material consumption quota: benzene 1 150kg/t, propylene 600kg/t, and the yield is 70% to 80%. Chlorobenzene Hydrolysis Method Chlorobenzene was hydrolyzed with caustic soda solution at high temperature and pressure of 3765438 0 degrees Celsius to produce sodium phenolate, and then neutralized with acid to obtain phenol. Crude phenol refining method is to refine crude phenol in coal tar. In the presence of solid molybdenum catalyst, benzene is oxidized by chlorine at high temperature to produce chlorobenzene and water, and chlorobenzene is catalytically hydrolyzed to produce phenol and hydrogen chloride, which can be recycled. Toluene oxidation method Toluene is oxidized by air under the action of cobalt salt catalyst to produce benzoic acid, and then benzoic acid reacts with air and water vapor under the action of copper catalyst to convert into phenol and carbon dioxide. Precautions Health hazards Phenol has a strong corrosive effect on skin and mucosa, which can inhibit the central nervous system or damage liver and kidney functions. Acute poisoning: Inhaling high concentration steam can cause headache, dizziness, fatigue, blurred vision and pulmonary edema. Accidental ingestion can lead to digestive tract burn, burning pain, exhaled gas with phenolic smell, vomit or bloody stool, gastrointestinal perforation, shock, pulmonary edema, liver or kidney damage, acute renal failure and respiratory failure. Eye contact can cause burns. It can be absorbed by burned skin and lead to acute renal failure after a certain incubation period. Chronic poisoning: it can cause headache, dizziness, cough, loss of appetite, nausea and vomiting, and proteinuria in severe cases. Can cause dermatitis. Environmental hazard: it is serious to the environment and can pollute water and atmosphere. Explosion hazard: this product is flammable, highly toxic and corrosive, which can cause burns to human body. First aid measures 1 skin contact: take off the contaminated clothes immediately, wipe them with glycerol, polyethylene glycol or the mixture of polyethylene glycol and alcohol (7:3), and then wash them thoroughly with water. Or rinse with plenty of flowing water for at least 15 minutes. See a doctor. Eye contact: lift the eyelid immediately and rinse it thoroughly with plenty of flowing water or normal saline for at least 15 minutes. See a doctor. Inhalation: leave the scene quickly and go to a place with fresh air. Keep the respiratory tract unobstructed. If you have difficulty breathing, give oxygen. If breathing stops, give artificial respiration immediately. See a doctor. 3 Ingestion: give vegetable oil 15 ~ 30ml immediately. Vomiting. See a doctor. Fire protection measures 1 hazard characteristics: flammable in case of open flame and high heat. Harmful combustion products: carbon monoxide and carbon dioxide. 3 Fire extinguishing method: Firefighters must wear gas masks and full-body fire protection suits to extinguish the fire in the upwind direction. Extinguishing agent: water, insoluble foam, dry powder, carbon dioxide. Emergency treatment of leakage 1 emergency treatment: isolate the leaked contaminated area and restrict access. Cut off the fire. It is recommended that emergency personnel wear dust masks (full face masks) and protective clothing. 2 a small amount of leakage: covered with dry lime and soda ash. 3. Large amount of leakage: collected and recycled or transported to the waste disposal site for treatment. Precautions for operation and disposal of storage 1: Close the operation and provide sufficient local ventilation. Isolate as much as possible. Operators must be specially trained and strictly abide by the operating procedures. Operators are advised to wear self-priming filter dust mask, chemical safety glasses, gas-proof clothes and chemical gloves. Stay away from fire and heat sources, and smoking is strictly prohibited in the workplace. Use explosion-proof ventilation system and equipment. Avoid dust. Avoid contact with oxidants, acids and bases. When handling, handle with care to prevent the packaging and containers from being damaged. Equipped with corresponding varieties and quantities of fire fighting equipment and leakage emergency treatment equipment. Empty containers may leave harmful substances behind. 5.2 Precautions for storage: Store in a cool and ventilated warehouse. Stay away from fire and heat sources. Avoid light. The storage temperature shall not exceed 30℃ and the relative humidity shall not exceed 70%. The package is sealed. Should be stored separately from oxidants, acids, alkalis and edible chemicals, and should not be mixed. Equipped with corresponding varieties and quantities of fire fighting equipment. The storage area should be equipped with suitable materials to control leakage. The "five pairs" management system of highly toxic substances should be strictly implemented. Allowable limit TWA: 19 mg/m? 3. ACGIH US IDLH: 100 ppm UK TWA: 19 mg/m? 3.HSE Germany MAC: 19 mg/m? 3. DFG former Soviet Union MAC: 0.0 1 mg/m? 3 (Determination of residential areas: sodium hydroxide is collected by bubbler, desorbed by sulfuric acid, and the allowable limit in water is analyzed by gas chromatography. Former Soviet Union MAC: 0.00 1 mg/L (drinking water) China MAC: 0.002 mg/L Determination: extract with dichloromethane, and analyze the acidity of phenol in related experiments by gas chromatography with flame ionization or gas chromatography plus mass spectrometry: 1. 2. Take a small amount of phenol solid in three test tubes, add 2-3 ml sodium hydroxide solution, 2-3 ml sodium carbonate solution and 2-3 ml sodium bicarbonate solution respectively, fully oscillate, and observe the comparison phenomenon (pay attention to whether there are bubbles in the test tubes with salt solution. 3. Take 2mL of sodium hydroxide solution in a test tube, add 2-3 drops of phenolphthalein test solution, and then add a small amount of phenol solid to observe the color change. Propagation phenomenon 1. Phenol can't turn litmus red. 2. Phenol solid is easily soluble in sodium hydroxide solution and sodium carbonate solution, and no bubbles are generated; Insoluble in sodium bicarbonate solution. 3. Phenol gradually lightens the red solution (sodium hydroxide solution plus phenolphthalein test solution). The experimental results show that phenol has weak acidity, and its acidity is between carbonic acid and bicarbonate ion. Phenol is too weak to turn litmus reagent red. (The color change range of litmus test solution is pH 5 ~ 8) Demonstration experiment In the newly prepared phenol solution, sodium hydroxide solution was added dropwise while shaking until it was just clarified, and the product was sodium phenolate. When carbon dioxide gas is continuously introduced, the solution becomes turbid again (carbon dioxide reacts with water to generate carbonic acid, and carbonic acid reacts with sodium phenolate to generate phenol and sodium bicarbonate). To sum up, according to the principle of making weak acid from strong acid, the acidity is H2CO3 >; > sodium bicarbonate. as we all know, carbonic acid is more acidic than phenol. Application field Industrial phenol is an important organic chemical raw material. It can be used to prepare phenolic resin, caprolactam, bisphenol A, salicylic acid, picric acid, pentachlorophenol, 2,4-D, adipic acid, phenolphthalein n- acetoethoxyaniline and other chemical products and intermediates, and can be used as chemical raw materials, alkyl phenols, synthetic fibers, plastics, synthetic rubber, medicines, pesticides, spices, dyes and coatings. In addition, phenol can also be used as solvent, experimental reagent and disinfectant. The aqueous solution of phenol can separate protein from DNA in plant cells, which is convenient for DNA staining. Medical usage and dosage 1. Disinfection of instruments and excreta treatment 1% ~ 5% aqueous solution. 2. Skin sterilization and itching relief: Apply 2% ointment to the affected area. 3. Otitis media should be treated with 1% ~ 2% phenol glycerin ear drops, three times a day. Widely used in the manufacture of phenolic resin, epoxy resin, nylon fiber, plasticizer, developer, preservative, insecticide, bactericide, dye, medicine, perfume, explosives and other preparations and specifications 1. Phenol ointment: 2%. 2. Phenol glycerol: ①1%; ②2%。 Taking it shows that the product has strong tissue permeability and is only used for small area of skin. High concentration external application can cause tissue damage and even necrosis. The aqueous solution is used on the body surface, the concentration shall not exceed 2%, and it will not be sealed after external use. Adverse reactions This product is corrosive and corrosive to tissues. It is reported that using phenol to disinfect and clean cradles and mattresses in poorly ventilated places will lead to neonatal hyperbilirubinemia, which has been proved to be fatal to infants. Contraindications: children with diaper dermatitis and infants under 6 months are prohibited. Avoid use on damaged skin and wounds. Characteristics: Important intermediate of benzene series. Also known as carbolic acid. White crystal, with low melting point (40.9 1℃), will turn red in air and light, and have a bad smell, with a boiling point of 18 1.84℃. Toxic to people, pay attention to prevent contact with skin. It is mainly made from cumene in industry. The output of phenol is large, 1984, and the global total production capacity is about 5 trillion tons. Phenol is widely used. Before World War I, the only source of phenol was extracted from coal tar. Most of them are obtained by synthetic methods. There are sulfonation method, chlorobenzene method and cumene method. Molecular structure: C atom on benzene ring is bonded by sp2 hybrid orbital, and O atom is bonded by sp3 hybrid orbital. Phenol is mainly used to make phenolic resin, bisphenol A and caprolactam. Among them, the production of phenolic resin is its biggest use, accounting for more than half of phenol production. In addition, a large amount of phenol is used to produce halogenated phenol. From monochlorophenol to pentachlorophenol, they can be used to produce herbicides, such as 2,4-dichlorophenoxyacetic acid (2,4-drops) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-drops); Pentachlorophenol is a wood preservative; Other halogenated phenol derivatives can be used as acaricides, leather preservatives and fungicides. Alkylphenol prepared from phenol is a monomer for preparing alkylphenol-formaldehyde polymer, which can be used as antioxidant, nonionic surfactant, plasticizer and petroleum product additive. Phenol is also the raw material for many drugs (such as salicylic acid, aspirin and sulfanilamide), synthetic spices and dyes (such as disperse red 3B). In addition, the dilute aqueous solution of phenol can be directly used as preservative and disinfectant. Storage mode: 1 Store in a cool and ventilated warehouse. Stay away from fire and heat sources. Avoid light. The storage temperature shall not exceed 30℃ and the relative humidity shall not exceed 70%. The package is sealed.
2. It shall be stored separately from oxidants, acids, alkalis and edible chemicals, and shall not be mixed. Equipped with corresponding varieties and quantities of fire fighting equipment.
3. The storage area should be equipped with suitable materials to control leakage. The "five pairs" management system of highly toxic substances should be strictly implemented. Study on degradation characteristics The research on phenol degradation abroad started earlier. So far, many phenol-degrading strains have been isolated and studied. At present, microorganisms that have been isolated and identified include rhizobia, Xanthomonas algae, yeast, Acinetobacter calcoaceticus and Pseudomonas. Aerobic Alcaligenes and Denitrifying Bacteria. The most common phenol-degrading bacteria are Pseudomonas and Aciobacter, and their maximum concentration of phenol degradation is generally below 1 200mg/L.1strain was isolated by Shen et al. This strain can grow with phenol, benzoic acid, p-cresol and benzene as the only carbon and energy sources, and has the ability to degrade monocyclic and bicyclic aromatic hydrocarbons at the same time. After physiological and biochemical analysis and 16SrRNA motif sequence analysis, it was identified as Rhodococcus PNAN5 strain. When the temperature is 20 ~ 40℃ and the pH is 7.0 ~ 9.0, the degradation efficiency of the strain is 80% ~ 100%, and the change of phenol concentration in the range of 2 ~ 10 mmol/L has no obvious effect on the degradation efficiency. The strain degrades aromatic hydrocarbons through the ring-opening pathway catalyzed by catechol 1 2- dioxygenase, which is different from the known rhodococcus turbidity degradation of aromatic hydrocarbons through catechol 2,3-dioxygenase. The relationship between initial phenol concentration, TOC and yeast biomass was discussed. The results showed that the degradation of phenol was closely related to the growth of yeast. The increase of initial phenol concentration inhibited the increase of yeast biomass and reduced the conversion rate. In the process of phenol degradation, the decrease of TOC is synchronous with phenol, and TOC mainly comes from yeast metabolites after phenol degradation. For the initial phenol concentration of 559.0 mg/L, 328.2 mg/L yeast (biomass) can be obtained by degrading 90% phenol, and the TOC in the culture medium can be degraded by about 87.3%. Nine strains of aerobic phenol-reducing granules, numbered Ⅰ1-Ⅰ 9, were isolated and identified by 16SrRNA gene sequence analysis, including Acinetobacter calcoaceticus, Pseudomonas and Brevibacterium. Except Ⅰ 3, all the other strains showed high phenol-reducing ability. When the concentration of phenol was 500 mg/L, strains Ⅰ1and Ⅰ 5 were compared with other strains. Strain ⅰ2, strain ⅰ6 and strain ⅰ8 showed strong aggregation ability, which weakened with the increase of pH value. The phenol-reducing ability of strain ⅰ3 is low, but it can enhance the aggregation ability of strain ⅰ2 and strain ⅰ8. Under the condition of hypoxia, 27 phenol-degrading bacteria were isolated. As a single carbon source and energy source, phenol shows the ability to reduce both phenol and nitrate content. The results show that aerobic degradation of 50 μmol phenol can reduce nitrate 140~200 μmol. Aerobic phenol-degrading bacteria were isolated from refinery wastewater in northeast Brazil. Candida tropicalis can survive in the environment with phenol concentration of 500 mg/L or 1 000 mg/L, and phenol is the only carbon source. With the increase of concentration, the degradation treatment takes longer, and a large number of polysaccharides are released in the middle of treatment to weaken the toxic effect of high concentration phenol. The results show that the strain has strong phenol degradation ability and can be used as a surfactant. Candida tropicalis isolated from industrial phenol-containing wastewater can treat phenol with the concentration of 1 000 mg/L, and its growth kinetics was analyzed. The results showed that the optimum growth conditions were μmax=0. 174/h, KS= 1 1.2 mg/L and ki = 298 mg/l. A new phenol-degrading bacterium EDP3 was successfully isolated from activated sludge, which can grow in an aerobic environment containing phenol, sodium benzoate, p-hydroxybenzoic acid, phenylacetic acid, benzene, ethylbenzene and benzyl alcohol. Pseudomonas MTCC 4996 isolated from the soil polluted by pulp wastewater can degrade phenol wastewater with a concentration as high as 1 300 mg/ L within 156 h, with a complete degradation pH range of 6.0~7.0, a temperature range of 15~ 45℃ and an optimum degradation zone of pH 7.0. When the temperature is 37℃ and the oscillation rate is 100~ 125 r/ min, it takes 66 h for complete degradation, and 84 h at rest. Low concentration of glucose and peptone can improve the treatment effect of phenol. The degradation rate of phenol is related to the added metal ions, and low concentrations of iron, copper, lead, zinc, manganese and mercury can improve the degradation rate. The maximum phenol-reducing concentration of Alcaligenes P5 isolated in aerobic environment is 0.29 mmol/L in the presence of oxygen and nitrate, while it is only 0. 16 mmol/L in aerobic environment. The isolated Acinetobacter calcoaceticus can efficiently degrade high-concentration phenol and efficiently aggregate with the participation of heat-sensitive adhesin protein. After 65438 0 weeks of continuous culture in SBR treatment system, the degrading bacteria can be immobilized into 2~3 mm particles with stable properties, which can treat 200~2 000 mg/L phenol. The corresponding phenol reduction rates in VSS were 993.6 and 565,438+09.3 mg/d, respectively, and a single strain could still survive at the phenol concentration of 65,438+0.500 mg/L. The results of * * * focused laser scanning microscope showed that Acinetobacter calcoacetate mainly survived below 200~250 microns from the outer surface and was covered with extracellular polymers to resist the toxicity of phenol. Research status of phenol-reducing genes: Phenol-reducing genes are usually arranged in clusters and located on large plasmids or chromosomes. In aerobic bacteria, phenol hydroxylase gene is the key gene to degrade phenol, and the first enzyme encoding phenol degradation pathway is responsible for converting phenol into catechol. Ortho-enzyme and meta-enzyme are responsible for the ring-opening cleavage of catechol into tricarboxylic acid (TCA) products. There are different pathways and enzyme systems for further degradation of catechol: catechol 2,3-dioxygenase (C23O, meta-cleavage) or catechol 1, 2- dioxygenase (CatA, ortho-cleavage). These dioxygenases (C23O, CatA) are encoded by C23O and CatA motifs, respectively, and have high homology in different degrading bacteria. Catechol 1, 2- dioxygenase was extracted from Candida albicans TL3, which has high phenol tolerance and high efficiency in reducing phenol. It was obtained by ammonium persulfate precipitation purification enzyme, dextran G-75 gel filtration and HiTrap Q agarose gel column chromatography. The optimum survival temperature is 25℃ and the optimum pH value is 8.0. Substrate analysis showed that the purified enzyme was one of catechol 1, 2- dioxygenase. The polypeptide sequencing fragment of catechol 1, 2- dioxygenase and the determination of MALDI-TOF/TOF total provided amino acid sequence information for BLAST analysis. The results of BLAST analysis showed that catechol 1, 2- dioxygenase was similar to that from Candida. Quantitative evaluation of phenol hydroxylase diversity in bioreactor by functional gene analysis technology. Firstly, the genetic diversity of excellent bacteria degrading phenol in laboratory-scale activated sludge was quantitatively analyzed. Synthetic sewage with phenol added was added to the first batch of cis-fluidized beds, and DNA genome was extracted from the obtained activated sludge for conservative amplification of large subunit phenol hydroxylase (LmPH) gene, and a clone library was generated. After phylogenetic analysis and 9-month real-time PCR analysis, the total copy number of LmPH gene remained basically stable, but in the improved phenol sludge, the degradation of phenol changed significantly, while the diversity of LmPH gene increased, which indicated that the degradation efficiency of phenol in activated sludge depended on the activities of some redundant species. 200 1, a phenol-degrading bacterium named R5 was isolated, and the phenol hydroxylase gene (Phc) of R5 degradation pathway was further studied. It is found that it has a different transcriptional regulation mechanism from other phenol hydroxylase genes. Three regulatory proteins participate in transcription, one of which is a co-accumulation protein in NtrC family, which regulates other phenol hydroxylases, the other inhibits the dislocation expression of Phc, and the other amplifies and expresses Phc. This detailed mechanism makes the phenol-degrading bacterium R5 show relatively high phenol oxygenation activity, which also shows that the expression patterns of degrading enzymes will be diversified, which may affect the degradation behavior. Pseudomonas. Strains degrading phenol and cresol were isolated from water polluted by phenol. According to the sequence analysis of phenol hydroxylase (LmPH) and catechol 2,3-dioxygenase, the plasmid was infected with catechol 1, 2- dioxygenase and the structure of one-component phenol hydroxylase encoded by pheBA. By comparing the catA motif sequences between the strains of indicator species and the strains grouped by genetic factors, it was found that the LmPHs and C23Os of the strains of Leuconostoc mendoza derived from genetic factor B were similar, while the genetic heterogeneity of Leuconostoc mendoza was obvious. P.xuscens strains obtained from genetic factors c and f contain genetic operon pheBA, and P. putida strains obtained from genetic factor b degrade phenol through ortho-pathway, and most of these strains have also detected this operon. The results of the combination of genetically diverse metabolic genes show that there is almost no intermediate pathway for the degradation of phenolic compounds. The suicide plasmid obtained from Tn5 transposon of E.coli S 17- 1 was fused with plasmid pAG408 of donor bacteria with antibiotic resistance. With the help of plasmid pRK600 containing mob gene of strain HB 10 1, gfp gene was transformed into recipient Pseudomonas by bacterial mating. A Pseudomonas sp. which can degrade phenol was isolated from industrial wastewater polluted by phenol. In this way, engineering bacteria with both phenol degradation and drug resistance were obtained, which emitted bright green light under ultraviolet irradiation, indicating that the fusion of green fluorescent protein gene gfp into Pseudomonas would not affect its degradation performance. Acinetobacter calcoaceticus PHEA-2 was isolated from refinery wastewater and enriched and domesticated in phenol and benzoic acid. Studies have shown that phenol hydroxylases of Acinetobacter calcoaceticus PHEA-2 and NCIB8250 are complex enzymes. The analysis of the whole nucleotide sequence and DNA sequence showed that the coding gene of phenol hydroxylase (mph) in Acinetobacter calcoaceticus PHEA -2 and its downstream coding gene were different from those in Acinetobacter calcoaceticus NCIB8250. Acinetobacter calcoaceticus PHEA-2 may have mph-ben-cat gene region. Conclusion It is an effective way to isolate high-efficiency phenol-degrading bacteria from polluted environment, study their degradation characteristics and apply them to wastewater treatment systems containing phenol and other refractory pollutants. The application of these degrading bacteria in biodegradable reactors, water supply equipment systems, polluted places and waste dumping places has broad application prospects.
Work summary of operation post 1
Time flies, time flies, and the three-month customer service internship period has passed in a