中文摘要：

目的利用克隆和表达sahH基因,恢复大肠杆菌密度感应缺陷株的甲基循环通路。方法通过扩增铜绿假单胞菌sahH基因,克隆到pGEX4T-1载体上,继而转入大肠杆菌密度感应缺陷株。诱导培养后,经考马斯亮蓝染色及蛋白印迹鉴定SahH-GST融合蛋白的表达。结果成功扩增并克隆了sahH基因,在大肠杆菌密度感应缺陷株中表达出约75 ku大小的蛋白,其大小与SahH-GST蛋白相符。结论大肠杆菌密度感应缺陷株内可以表达外源基因sahH,恢复了甲基循环的该菌株可进一步应用于密度感应与代谢循环调节作用的实验。

英文摘要：

Objective Make use of cloning and expression of sahH gene to recover the activated methyl cycle of Escherichia coli quorum sensing defective strain.Methods The sahH gene of pseudomonas aeruginosa strain PAO1 was amplifided and introduced into pGEX4T-1 vector,and then transformed into E.coli quorum sensing defective strain.After induction and culture,Coomassie brilliant blue and Western blot were performed to identify the expression of SahH-GTS fusion protein.Results The sahH gene was successfully amplified and cloned.The SahH-GTS fusion protein,whose molecular weight was about 75 ku,was expressed in the E.coli quorum sensing defective strain.Conclusions In the quorum sensing defective strain of E.coli,the exogenous gene sahH could be expressed.This E.coli strain,which has recovered activated methyl cycle,can be used to do research in the regulation of quorum sensing and methyl metabolic cycle subsequently.