鄰苯二甲酸酯（phthalic acid esters,PAEs）的毒性和致癌性受到越來越多的關(guān)注。PAEs在不同環(huán)境介質(zhì)中普遍檢出,甚至極地偏遠地區(qū)如北極圈內(nèi)也有檢出。因其半揮發(fā)性和疏水性,PAEs能夠長距離運輸并在環(huán)境中存留。PAEs可以在厭氧和營養(yǎng)不良的環(huán)境中存留多年。Gordonia屬（放線菌門）在PAEs降解中尤其重要。雖然微生物降解PAEs的途徑已被闡明,但菌株和酶的基因信息有限且能夠水解高分子量PAEs的酶很少被報道。利用Biosciences RS II平臺和單分子實時（SMRT）技術(shù)對分離的食堿戈登氏菌YC-RL2基因組進行測序。利用NCBI原核生物基因組注釋程序進行注釋。生成的基因組序列為4979656 bp,平均G+C含量為67.45%。平均核苷酸一致性證實菌株YC-RL2確實是G.alkanivorans。在COG數(shù)據(jù)庫中進行檢索;3132個CDSs聚類到COG家族,預測有1808個CDSs參與了111個通路。95個KEGG注釋基因被預測參與了外源物質(zhì)降解。未發(fā)現(xiàn)PAEs降解操縱子,表明菌株YC-RL2具有一種新PAEs降解途徑。203個CDSs和22個CDSs... 

【文章頁數(shù)】：137 頁

【學位級別】：博士

【文章目錄】：
摘要
abstract
List of Abbreviations
Chapter1:General Introduction
    1.1 Background
    1.2 Problem statement
    1.3 Justification of the study
    1.4 General objective
    1.5 Specific objectives
Chapter2:Literature review
    2.1 Occurrence of PAEs
        2.1.1 Surface waters and sediments
        2.1.2 Occurrence in Air
        2.1.3 Agricultural soils
        2.1.4 Wastewater treatment plants and sludge
        2.1.5 Occurrence in landfills
        2.1.6 Food,beverages and personal care products
    2.2 Eco-toxicological effects of PAEs
        2.2.1 Effect of PAEs on soil properties and crops
        2.2.2 Effect on aquatic organisms
        2.2.3 Effects on terrestrial organisms
        2.2.4 Effect on humans
    2.3 Microbial removal of PAEs
        2.3.1 PAEs biodegradation pathways in bacteria
        2.3.2 Role of genus Gordonia in degradation of PAEs
Chapter3:Genome sequencing,annotation and comparative analysis of strain YC-RL
    3.1 Introduction
    3.2 Materials and methods
        3.2.1 Chemicals and media
        3.2.2 Substrate utilization tests and intermediate analysis
        3.2.3 DNA extraction,genome library preparation and sequencing
        3.2.4 Phylogenetic and comparative genomic analysis
        3.2.5 Prediction of secondary metabolite potential
        3.2.6 Heavy metal tolerance tests
        3.2.7 Accession numbers
    3.3 Results
        3.3.1 Genome sequence and annotation results
        3.3.2 Classification
        3.3.3 COG analysis and KEGG analysis
        3.3.4 Analysis of phthalate catabolic genes
        3.3.5 Secondary metabolite biosynthesis potential
        3.3.6 Heavy metal resistance
        3.3.7 Genetic basis for colony morphology changes
    3.4 Discussion
    3.5 Conclusion
Chapter4:Cloning and expression of a novel carboxylesterase Car259 capable of hydrolyzing Di-2-ethylhexyl phthalate
    4.1 Introduction
    4.2 Materials and methods
        4.2.1 Chemicals and reagents
        4.2.2 Cloning,expression and purification of Car
        4.2.3 Enzyme assay
        4.2.4 Substrate specificity
        4.2.5 Detection of degradation intermediates
        4.2.6 Homology modeling and model verification
        4.2.7 Protein-ligand docking and visualization
        4.2.8 Construction of mutants
    4.3 Results
        4.3.1 Expression and purification of Car
        4.3.2 Multiple sequence alignment and phylogenetic analysis
        4.3.3 Effect of pH,temperature,ions,solvents and detergents on Car259 activity
        4.3.4 Substrate specificity
        4.3.5 Enzyme Kinetic parameters
        4.3.6 Degradation intermediates
        4.3.7 Homology modeling and docking results
    4.4 Discussion
    4.5 Conclusion
Chapter5:Biochemical and structural characterization of a monoethylhexyl phthalate hydrolase(MehpH)
    5.1 Introduction
    5.2 Materials and methods
        5.2.1 Chemicals,solutions and media
        5.2.2 Protein purification
        5.2.3 Enzyme activity assays
        5.2.4 Enzyme structure modeling
    5.3 Results
        5.3.1 Protein purification
        5.3.2 Enzyme activity assays
        5.3.3 Enzyme structure modeling
    5.4 Discussion
    5.5 Conclusion
Chapter6:General conclusions and recommendations
    6.1 Conclusions
    6.2 Recommendations
References
Acknowledgements
Author’s Resume


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期刊論文
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[2]鄰苯二甲酸酯在不同類型土壤-植物系統(tǒng)中的累積特征研究[J]. 宋廣宇,代靜玉,胡鋒.  農(nóng)業(yè)環(huán)境科學學報. 2010(08)
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