Development of the method for polychlorinated biphenyl treatment by the combination of physicochemical and biological degradation

物化与生物降解相结合的多氯联苯处理方法的开发

• 批准号: 05454612
• 负责人: YANO Keiji
• 金额: $ 4.54万
• 依托单位: Nagaoka University of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05454612/
• 关键词: PCB; Chimeric enzymes; Site-directed mutagenesis; Conjugation; Ultraviolet treatment; 分解系遺伝子; クローニング; 物理化学的処理法

In this research project, we analyzed the structure of PCB degradation enzymes and discussed about their reaction mechanism. The biphenyl dioxygenase (BphA) and 2,3-dihydroxybiphenyl dioxygenase (BphC) were selected for these experiments. Chimeric genes were constructed with the combination between benzene degradation genes and the resulted chimeric enzymes suggested that the amino acid differences of enzymes responsible for the differences of substrate specificity. We could also create the mutated enzymes that had different specificity for substrates.To construct a genetically manipulated microorganism, we had introduced the PCB degradation genes to soil bacteria. The conjugants showed biphenyl degradation activity and this ability was inducible by biphenyl.The PCB solution was treated by ultraviolet (UV) irradiation and the dechlorination of PCBs was analyzed by GC-MS.The UV-treated PCB solution was used for the biological treatment and the PCBs were completely degraded by these combination.From our experiments, we concluded that few amino acid differences of degradation enzymes effect to the substrate specificity and the UV-treatment is very useful for the complete degradation of PCBs.

本研究对多氯联苯降解酶的结构进行了分析，并对其反应机理进行了探讨。选择联苯双加氧酶（BphA）和2，3-二羟基联苯双加氧酶（BphC）用于这些实验。将苯降解基因组合构建嵌合基因，得到的嵌合酶表明酶的氨基酸差异导致了底物特异性的差异。为了构建基因工程微生物，我们将PCB降解基因导入土壤细菌中。结合物具有降解联苯的活性，且这种降解能力是由联苯诱导的。用紫外光（UV）照射PCB溶液，用GC-MS分析PCB溶液的脱氯情况。将UV处理的PCB溶液用于生物处理，这些结合物可以完全降解PCB。我们得出的结论是，降解酶的氨基酸差异对底物特异性的影响很小，紫外线处理对于多氯联苯的完全降解非常有用。