Screening, Identification And Application In Soil Remediation Of Polycyclic Aromatic Hydrocarbons Degrading Bacteria

Polycyclic aromatic hydrocarbons (PAHs) are a class of widely distributed in theenvironment of persistent organic pollutants, and do great harm to pass on the ecolo--gical environment and human health through the food chain. Biodegradation is themost important mothod of removing PAHs in the environment (soil, sediment,water).In this thesis, we collected soil samples from Karamay heavy pollution, under the sel--ective pressure of the persistence of PAHs model compounds Philippines enrichmentdomesticated, PAHs-phenanthrene degradation strains could effectively degrade PA--Hs screened a bacteria from physiology and biochemistry, molecular biology, a moresystematic study, to investigate the degradation characteristics of process conditionsto optimize the degradation of phenanthrene, examine the practical application of stra--in contaminated soil in the Philippines, in order to further study of polycyclic aromat--ic hydrocarbons degradation gene construct genome library screening degradation offunctional genes. The main contents and experimental results are summarized as foll--ws:(1) To the Philippines as the object of study, screened from Karamay heavy oilcontaminated soil to the strains of the Philippines has good degradation effect strainsy-8. By morphological observation, physiological and biochemical indexes and16SrDNA sequence analysis, the strain was identified as Pseudomonas geniculata. Thestrain high concentration Philippines well tolerated, the highest tolerable qualityconcentrations of up to3000mg/L. Electron transfer respiratory chain activity isproportional to the number of bacteria.(2) From the different conditions of the inoculum size, temperature, and pHexamine the strain Philippines degradation. In liquid shake flask experiments, thestrain on the degradation of phenanthrene in line with first-order kinetics. To furtherenhance the phenanthrene degradation rate, response surface methodology andanalysis, the phenanthrene degradation rate of surfactant formulations: Tween-80 concentration of581mg/L, Triton X-100concentration of185mg/L, SDSconcentration of22mg/L. Best under optimal conditions, the strain y-8ofphenanthrene degradation rate of91.2%, compared to86.65%before optimization,phenanthrene degradation rate close to4.55%.(3) The strains y-8degradation of phenanthrene conditions for single factorexperi--ment.The results show that: the strain y-8in the Philippine concentration of10μg/kg, temperature30~40℃, inoculation amount of40~50%, pH7.0~8.0,Tween-80concentration of100~200mg/L shake flask culture conditions15d ofphenanthrene degration rate of78.7%. Monod model, the establishment of themathematical equations of the Philippine contaminated soil, and get the responsemodel for.(4) For the analysis of the functional gene of the strain degradation ofphenanthrene, extracting the genomic DNA of the strain y-8of Sau3A I digestedgenomic DNA was cut plastic recycling1~3kb gene fragment of pUC-18vector andintroduced into E. coli DH5a, build phenanthrene degrading strains y-8of thegenomic library.