TABLE 2.
Influence of furA and furB gene deletions on siderophore biosynthesis and metal resistance
| Parent and mutant strain | Diam of the haloa (mm) | MIC (mM) ofb: |
|||
|---|---|---|---|---|---|
| Cd2+ | Co2+ | Ni2+ | Zn2+ | ||
| CH34 wild type | 22 ± 2 | 2.5 | 11.5 | 7.5 | 7.0 |
| ΔfurA | 24 ± 3 | 2.0 | 6.0 | 5.0 | 4.5 |
| ΔfurB | 19 ± 2 | 2.0 | 6.0 | 7.5 | 5.0 |
| ΔRmet_1113-Rmet_1114 (iucA-iucC) | 0 ± 0*** | 2.5 | 6.0 | 6.5 | 4.75 |
| ΔRmet_1118 (aleB) | 17 ± 2* | 1.5 | 6.0 | 5.5 | 4.75 |
| ΔRmet_5806-Rmet_5807 (fecA1-fecA2) | 22 ± 4 | 2.0 | 7.0 | 6.0 | 5.0 |
| AE104 wild type | 19 ± 2 | 0.2 | 0.35 | 0.7 | 0.15 |
| ΔfurA | 27 ± 3** | 0.2 | 0.3 | 0.5 | 0.15 |
| ΔfurB | 17 ± 3 | 0.2 | 0.35 | 0.5 | 0.15 |
| ΔRmet_1113-Rmet_1114 (iucA-iucC) | 0 ± 0*** | 0.2 | 0.3 | 0.6 | 0.15 |
| ΔRmet_1118 (aleB) | 16 ± 2 | 0.2 | 0.3 | 0.5 | 0.15 |
| ΔRmet_5806-Rmet_5807 (fecA1-fecA2) | 17 ± 3 | 0.2 | 0.35 | 0.5 | 0.25 |
a
A CAS assay was performed with C. metallidurans wild-type strain CH34, its plasmid-free derivative strain AE104, and single-deletion mutants of these strains. The diameter of the yellow halo around the wells filled with the cell suspensions was determined. Three experiments were performed, and mean values and deviations are indicated. Significance was determined with Student's t test. ***, >99.9%; **, >99%; *, >95%.
b
The MICs were determined for the CH34 and AE104 derivatives after 5 days of growth at 30°C on TMM. Three experiments were performed with identical results.