Integration Site Library for Efficient Construction of Plasmid-Free Microbial Cell Factories in Escherichia coli

Enhanced production stability and efficiency along with a decrease in production costs are required to build efficient microbial cell factories. Target genes can be integrated into the genome to enhance genetic stability, reduce reliance on antibiotics, and alleviate the metabolic burden. However, selecting the optimal insertion site for the desired gene expression levels remains challenging. Therefore, 18 commonly used