| Summary: | 碩士 === 國立陽明大學 === 生物化學研究所 === 87 === The air pollutants such as NO、O3、CO2、SO2 could be uptaked and metabolized by some plants. However,it is still no report about the air pollutants: polycyclic aromatic hydrocarbons (PAHs) that could be absorbed and degraded by specific plants. In order to investigate the subject, 39 species of plant leaves was collected from different areas. These plant leaves were broken by pestle in the liquid nitrogen, and extracted with the buffer. Five PAHs: fluorene, phenanthrene, anthracene, fluoranthene, benzo(a)pyrene were used as substrates for screening various extracts of leaves. We find three species of plants: Hibiscus tiliaceus and Duranta repens and Cuscuta sp. have the PAHs degrading activity.
To purify the PAHs-degrading enzymes, ion-exchange chromatography was used. The pass-through fractions of Sephadex CM-25 and Sephadex QAE-25 were collected. By TLC method, no obvious activity was found except the CM fraction of Cuscuta sp. The CM pass through fraction of Cuscuta sp. was collected and heated in the boiling water, and resulted in the greatly lost of the activity. To estimate the molecular weight range, the method of centriplus was used. The result indicated that four PAHs (Phenanthrene, Anthrene, Fluoranthene, Benzo(a)pyrene) degrading factors have a molecular weight range near the 100KDa. Therefore,the four PAHs degrading factors should be proteins. Futhermore, fluorene-degrading factor have a molecular weight below 10KDa, that was different from the four PAHs-degrading factors mentioned above.
After CM pass fraction applied onto the sephadex QAE-25 column, it was eluted with different ionic strength buffer. The enzyme activity was in the 0.2 M NaCl fraction.
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