Construction method and application of thallus self-destruction system

The invention provides a construction method and application of a thallus self-destruction system. Comprising the following steps: connecting an SMnuc l ease gene of serratia marcescens to a rigorous inducible promoter; the method comprises the following steps: transferring a gene containing non-restriction nuclease and a rigorous inducible promoter into a host strain by using a vector, and culturing and fermenting; and adding an inducer, continuously culturing the host cells, and detecting the nuclease digestion effect of the host cells. When the fermentation of the target product is completed, the SMnuc l ease gene starts to express nuclease by adding an inducer capable of inducing the PJExD promoter to promote expression, and digests nucleic acid in microbial cells to generate 3-5 oligonucleotides, thereby achieving the purpose of eliminating gene residues. 本发明提供了菌体自毁系统的构建方法及应用。包括如下步骤：将粘质沙雷氏菌的SMnuc l ease基因连上严谨型诱导型启动子；利用载体将含有非限制性核酸酶基因连上严谨型诱导型启动子转入宿主菌株中，进行培养发酵；加入诱导剂，对进宿主细胞继续培养，再对宿主细胞核酸酶消化效果检测。当目标产物发酵完成时，通过添