Escherichia coli
Mutator and targeting plasmid were transformed into E. coli DH5. Transformed strains were inoculated into shake flasks containing 50 mL of LB medium containing antibiotics and cultured at 37 C, 220 r.p.m. for 12 h. Then, 1 l of culture was inoculated into 1 ml of fresh LB medium was cultured for 24 h under the same conditions. After repeating the inoculation and culture 10 times, the pellets were obtained by centrifugation and directly used as templates for PCR amplification. The target plasmid was divided into 16 fragments and amplified for NGS.