Fig. 4
Growth curve of E. faecalis under different conditions. OD optical density. a OD curve of E. faecalis (1 × 106 CFUs/mL) incubated with different concentrations of AgNO3. b OD curve of E. faecalis (1 × 106 CFUs/mL) incubated with different Ag+–Zn2+ ratios. c OD curve of E. faecalis (1 × 108 CFUs/mL) incubated with different concentrations of AgNO3. d OD curve of E. faecalis (1 × 108 CFUs/mL) incubated with different Ag+–Zn2+ ratios. e OD curve of E. faecalis (1 × 103 CFUs/mL) incubated with different concentrations of Zn(NO3)2·6H2O. f OD curve of E. faecalis (1 × 108 CFUs/mL) pretreated with Zn2+ only. (Asterisk: significant difference when compared with the blank control group (p < 0.05); ▲significant difference when compared with the Zn2+ only groups (p < 0.05); #significant difference when compared with the Ag+ only groups (p < 0.05); Groups inside boxes in the corresponding chart had the same labels as the legend