| Metal ions | Concentration (mM) | *Relative activity (%) | |
| Actinomyces viscosus | Actinomyces israelii | ||
| Ca2+ | 5 10 | 136.36 ± 0.08 151.82 ± 0.03 | 62.50 ± 0.53 12.50 ± 0.02 |
| Fe2+ | 5 10 | 697.27 ± 0.04 2236.36 ± 0.04 | 858.75 ± 0.02 2158.75 ± 0.03 |
| Cu2+ | 5 10 | 50.91 ± 0.02 18.18 ± 0.02 | 57.50 ± 0.02 25.00 ± 0.03 |
| Mg2+ | 5 10 | 27.27 ± 0.01 13.64 ± 0.02 | 8.13 ± 0.01 6.25 ± 0.03 |
| Mn2+ | 5 10 | 106.36 ± 0.01 124.54 ± 0.02 | 62.50 ± 0.01 50.47 ± 0.02 |
| Hg2+ | 5 10 | 9.09 ± 0.01 5.45 ± 0.02 | 12.50 ± 0.02 1.25 ± 0.03 |
| EDTA | 5 10 | 7.04 ± 0.02 0.00 | 12.50 ± 0.01 0.00 |