Isolation of a novel Co-resistant bacterium and the application of its siderophore in Co recovery from an aqueous solution.

Siderophores are considered to have a good potential as decontamination agents owing to their metal-chelating abilities. In order to confirm whether siderophores can be used in the recovery of metal ions, a siderophore (or metallophore) exhibiting Co-chelating activity was screened to demonstrate its ability to recover Co from an aqueous solution. A siderophore-producing bacterium, Pandoraea sp. HCo-4B, was identified from a screen of Co-resistant bacteria grown in an aerobic enrichment culture with a Co-supplemented medium. After incubation of the crude extracted siderophore in a Co-containing solution, the Co-siderophore complex was adsorbed on to a C column. The bound Co was eluted from the column by the addition of 10 mM HSO. The recovered amount of Co was proportional to the amount of the added siderophore. We observed that the siderophore identified in this study binds to Co at a 1:1 ratio.