Capacity of siderophore - producing alkalophilic bacteria to accumulate iron, gallium and aluminum

The ability of alkalophilic bacteria to remove iron, gallium and aluminium from culture media is reported. Of six bacterial strains grown in the presence of iron, gallium or aluminium (10-mu-M), five were able to accumulate iron or gallium, but only two depleted the aluminium stock. A comparison of gallium removal under low (< 1-mu-M) or high (10-mu-M) iron conditions showed that two isolates accumulated gallium only under low-Fe conditions. One isolate, a coryneform bacterium, was able to grow in the presence of 1, 10 and 100 mg gallium/1, but growth and siderophore production were affected at high gallium concentration. Similar concentrations of gallium were accumulated from cultures initially containing 1 or 10 mg gallium/1.