Microbial Degradation of Dioxin and Its Related Compounds

为了阐明菌株DBF63降解二恶英和二苯并呋喃途径中涉及的酶包括初始双氧酶的基因，对分离到的基因进行了克隆和测序。已分离到1个特异裂解酶克隆（pLM1）。此外，还发现了另一个内切酶基因。分离到的中间裂解酶基因具有Sph1位点。利用内切酶Sph1，利用大肠杆菌MV1184和pUC119宿主载体系统，用霰弹枪法克隆另一个基因。将儿茶酚、3-甲基儿茶酚、4-甲基儿茶酚和3-苯基儿茶酚（底物2,2'，3-三羟基联苯的类似物）的溶液混合喷洒到转化子菌落上，检测到活性靶向克隆。新获得的质粒pKN1的限制性内切酶位点与另一个具有间环裂变酶活性的克隆完全不同。

To elucidate the genes of the enzymes including initial dioxygenases involved in the degradation pathways of dioxin and dibenzofuran by strain DBF63, the cloning of the genes and sequencing of the isolated genes were carried out.One clone (pLM1) specifing meta cleavage enzyme has been isolated. Another gene for meta cleavage enzyme was also found out. The isolated gene for meta cleavage enzyme has Sph1 site. Restriction enzyme Sph1 was used to obtain another gene by shot gun cloning with use of host vector system of E.coli MV1184 and pUC119. An active tageted clone was detected by spraying the solution mixture of catechol, 3-methylcatechol, 4-methylcatechol and 3-phenylcatechol which are analogus compouds of substrate 2,2', 3-trihydroxybiphenyl to the colonies of transformants.The newly obtained plasmid pKN1 has completely different restriction enzyme site with the other clone which has activity of meta ring-fission enzyme.