TABLE 2.
Utilization of ferric alcaligin by wild-type and mutant B. bronchiseptica strainsa
| Indicator strain | Growth zone (mm) surrounding wells containing purified alcaligin at concn of:
|
||
|---|---|---|---|
| 63 μg/ml | 125 μg/ml | 250 μg/ml | |
| B013N (wild type) | 16 | 20 | 24 |
| BRM17 | — | — | — |
| BRM17(pBBR1MCSb) | — | — | — |
| BRM17(pBB24ΔfauA) | — | — | — |
| BRM17(pBB24) | 17 | 22 | 27 |
| BRM18 | — | — | — |
| BRM18(pBBR1MCS) | — | — | — |
| BRM18(pBB24) | 18 | 23 | 28 |
a
Aqueous alcaligin solution (50 μl/well) at the indicated concentration was added to 6-mm-diameter wells in EDDA-containing iron-restricted agar medium seeded with indicator strains, and diameters of growth zones were measured after 18 h incubation at 37°C. No growth occurred in the absence of added alcaligin siderophore. —, no detectable growth stimulation.
b
Plasmid vector control.