抗砷载体的构建及在氧化亚铁硫杆菌中的表达

CONSTRUCTION OF ANTIARSENICAL VECTOR AND EXPRESSION IN THIOBACILLUS FERROOXIDANS

利用ＤＮＡ体外重组技术，将抗砷质粒ｐＵＭ３经ＨｉｎｄⅢ酶切后得到的４．３ｋｂ抗砷片段克隆到有广泛寄主的ＩｎｃＱ质粒ｐＪＲＤ２１５的ＨｉｎｄⅢ位点上，构建了一个新的抗砷质粒ｐＳＤＸ３。砷抗性研究表明，在大肠杆菌中，ｐＳＤＸ３的抗砷水平与ｐＵＭ３相近。将ｐＳＤＸ３通过接合的方式引入氧化亚铁硫杆菌Ｔｆ－５９中并得到了表达，与对照相比，含质粒ｐＳＤＸ３的Ｔｆ－５９抗砷水平有了很大的提高。

A 4. 3kb Hind Ⅲ fragment of antiarsenical plasmid pUM3 was cloned into the wide-host-range IncQ plasmid pJRD215 and a new antiarsenical vector pSDX3 was produced by using the recombination technique in vitro. The study on arsenical resistance showed that the level of arsenical resistance of pSDX3 in E. coli was similar to that of pUM3. The plasmid pSDX3 was introduced into Thiobacillus ferrooxidans Tf-59 by conjugation and was expressed in it. Compared with Tf-59, the level of arsenical resistance of Tf-59 (pSDX3)was greatly raised.