中文摘要：

细菌在高细胞密度下可以产生化学信号分子调控细菌相关基因的表达，这种信号分子被称为自体诱导物（Autoinducer，AI）。采用检测菌株JZA1在中慢生型天山根瘤菌CCBAU060A（Mesorhizobium tianshanenseCCBAU060A）培养上清液中检测到了高活性的自体诱导物；利用转座子随机突变的方法获得了AI缺失突变株，并克隆得到了相关的自体诱导物合酶基因；将自体诱导物合酶基因在大肠杆菌中进行表达，对大肠杆菌重组菌株进行自体诱导物检测发现，该合酶基因在大肠杆菌中能够合成四种自体诱导物分子。

英文摘要：

Bacteria, when high in cell density, will produce chemical signal molecules, called atuoinducers （AI） , to regulate gene expression. Autoinducers of high activity in the spent culture supernatant of Mesorhizobium tianshanense CCBAU060A were detected with the aid of AI bioassay strain JZA1. One autoinducer-deficient mutant was obtained by screening Mesorhizobium tianshanense CCBAU060A mutated with mariner transposon. Analysis of the flanking region of transposon insertion found a LuxI-type synthase gene, mrtI2, which was. cloned into the broad host range expression vectors pYC12, and transformed into Escherichia coli DH5α . The putative AHL synthase gene was overexpressed in Escherichia coli, and four different autoinducers could be detected in the supernatant of the positive recombinant.