Fig. 2
Gene deletion and insertion using the CRISPR–Cpf1 system, and the effects of RecET expression and promoters that drive FnCpf1 expression are represented. a Colonies formed under different conditions. When FnCpf1 and crRNA were both expressed, the number of colonies was several orders of magnitude lower than that observed in the control, indicating that the Cpf1–crRNA complex is functional in C. glutamicum. The expression of RecET significantly increased the number of colonies, probably by improving the homologous recombination (HR) activity. Ptuf-driven expression of FnCpf1 decreased the number of colonies compared to that in the PlacM-FnCpf1 expressing cassette. b Gene deletion efficiencies (deletion of 534 bp from CgDel); c Gene integration efficiencies (insertion of 528 bp into CgInt). The introduction of RecET and the Ptuf promoter significantly enhanced gene deletion and integration. Experiments were performed in triplicates. Values are presented as mean ± SD. **P < 0.01, *** P < 0.001