苏云金芽胞杆菌(Bacillus thuringiensis，Bt)是世界上应用最为成功的微生物杀虫剂。噬菌体污染是Bt生产过程中的最大危害。前期的青年基金项目已经通过基因组学、比较基因组学、以及蛋白质组学等技术，发掘了系列新型控制Bt溶源性噬菌体进入裂解循环的关键遗传因子，包括：噬菌体感染和宿主特异性关键蛋白ORF1、ORF3和ORF17；宿主免疫噬菌体关键因子Crispr/cas系统；噬菌体裂解细菌细胞关键蛋白ORF57和ORF42；以及ABC transport通路相关蛋白等。本课题将在此基础上验证这些关键因子在Bt噬菌体与其宿主相互作用过程中的功能，并解析它们的作用模式。本课题的研究将有利于我们了解Bt与其噬菌体相互作用的分子机制，并可为通过遗传改造从基因水平上控制Bt生产中的噬菌体污染问题提供理论基础。

As a microbial insecticide, Bacillus thuringiensis (Bt) has been successfully used worldwide. During Bt fermentation, the loss caused by lysogenic bacteriophage was very severe. At the support of the former project (youth foundation No. 31000020), we confirmed a series of novel genetic factors that control bacteriophage transition from lysogenic state to lytic cycle, which contain the proteins (ORF1, ORF3, ORF17) that help bacteriophage target its host; the CRISPR/Cas immune system encoded by some Bt plasmids; proteins that bacteriophage adopt to lyse bacterial host cell (ORF57 and ORF42); and ABC transport pathway which may involved in host immune to lysogenic bacteriophage. In this research, we will focus on the function and the action model of these factors during the interaction between bacteriophage and Bt host. This research will help us better understand the molecule mechanism of the interaction between Bt and their bacteriophage, and the results will provides novel theory bases for controlling bacteriophage in Bt fermentation at genetic level.