Fig. 1
Effects of copper concentrations on the cellular growth of M. xanthus and the cas9 gene expressions. a The growth abilities of DK1622 and the DK-Cas9 and DK-Cas9–sgRNA mutants in CTT medium containing different concentrations of copper. The cas9 gene is controlled by the PcuoA promoter. Cells grown in the absence of copper were diluted to 0.05 OD600 value in the CTT medium containing the indicated copper concentration, which were then incubated at 30 °C for 24 h, and monitored the cell density. b Expressions of the cas9 gene in DK-Cas9–sgRNA induced with different copper concentrations. At 0 h, the cells were treated with different copper concentrations in CTT medium. After 5 h of incubation, the cells were harvested by centrifugation, and further incubated in CTT medium. The cas9 gene expressions in cell were assayed. Experiments were performed in triplicate