Study Of Characterization For Polycyclic Aromatic Hydrocarbons By Pseudomonas Aeruginosa NY3

Polycyclic aromatic hydrocarbons (PAHs) are a class of teratogenic, carcinogenic,mutagenic organic pollutants. They are difficult to be removed because of poor watersolubility and long standing the soil and sediment. Environmental pollution is increasingcaused by PAHs with the rapid development of modern industry. So the research hasbecome a hot topic for removing PAHs rapidly and effectively in the environment. This thesisis a study for Pseudomonas aeruginosa NY3which can be saved in laboratory and degradatePAHs，in order to grasp and improve the metabolism of carbon sources degradation of PAHsand master their degradation pathway by NY3. The results are as follows:（1）NY3bacteria cells of maximum growth had the biggest degradation activity ofphenanthrene when NY3bacteria growed as a variety of sources of carbon. Bacteria cellactivity was the largest for LB carbon source first, the second were phenanthrene and catechol.Glucose, protocatechuic acid, salicylic acid, phthalic acid and other carbon sources to growthof bacteria cells activities were under the above carbon sources during the degradation ofphenanthrene by NY3. Removal efficiency was about46.26%for degradation of phenanthrenewithin60min when NY3cells reached maximum growth In LB medium. The degradation rateof phenanthrene were approximately8.99%and8.97%within60min when the NY3growedon phenanthrene, catechol as sole carbon source and energy. While phenanthrene removalrate were only3.54%,7.07%,5.96%,4.01%under the same conditions.(2) Fe2+had a significant role in promoting for harvested bacterias during maximumgrowth in the progress of degradating phenanthrene by NY3bacteria cells in LB medium.Iron promoted the degradation of phenanthrene then degradation rate of phenanthrene wasincreased by14.37%within30min for growing17h bacteria cells. Fe2+had no significantrole and degradation of phenanthrene activity was small for the cells of early growth and decline phase.(3) Alkanes as the carbon source of cometabolic had a significant role in promoting todegradation of phenanthrene and anthracene by the NY3bacteria, but inhibiting pyrenedegradation efficiency. Phenanthrene degradation rates were increased by34%,38%and42.65%and cell growth significantly improved after48h when adding n octane, n dodecane,n hexadecane and compared to phenanthrene as the sole carbon source. Anthracene removalefficiencies were improved40.18%,15.27%,53.57%within48h,when plusing n octane,n dodecane, n hexadecane as cometabolic carbon source, compared with anthracene as thesole carbon source growth by the NY3bacteria synchronized degradation. Synchronizationremoval rate of pyrene were reduced by28.44%,14.79%and29.1%for pyrene growing48h.(4) It was found five major metabolites of phenanthrene in the process of degradation byPseudomonas aeruginosa NY3. They were benzoic acid, salicylic acid, alpha naphthol,1hydroxy2naphthoic acid,and acetic acid o hydroxyphenyl carbonyl, of which1hydroxy2naphthoic acid was the most vulnerable to the accumulation of intermediates.And o hydroxyphenyl carbonyl acid was the first report of Pseudomonas aeruginosa to thedegradation of phenanthrene intermediates. P. aeruginosa NY3could grow on its metabolitessuch as α naphthol, salicylic acid, benzoic acid as sole carbon source and energy. P.aeruginosa NY3could also grow on1hydroxy2naphthoic acid as sole carbon source andenergy,although it was the most vulnerable to the accumulation of intermediates. P. aeruginosaNY3could degradate1hydroxy2naphthalene acid and could be converted into the productof α naphthol, salicylic acid, benzoic acid.