Catechols are co-planar cis-diols known to form stable, isolable complexes with borate under weakly basic conditions. We exploited this chemistry and developed a boronate affinity chromatography for isolating catechol siderophores. The method was applied to the isolation of chrysobactin, enterobactin, and an unknown catechol siderophore produce by Erwinia carotovora subsp. carotovora W3C105. Yields of chrysobactin and enterobactin purified by boronate affinity chromatography were at least two-fold greater than those achieved through alternate methods. The unknown catechol produced by E. carotovora subsp. capotovora W3C105 was isolated by boronate affinity chromatography and shown to be identical to chrysobactin. Boronate affinity chromatography enabled separation of catechol from its rust-colored decomposition products, and simultaneous isolation of catechol and hydroxamate siderophores. Boronate affinity chromatography is a rapid and efficient method for purifying catechol siderophores from bacterial culture supernatants.
Bibliographical noteFunding Information:
We thank J. B. Neilands for the generous gift of synthetic chrysobactin, and J. E. Loper and D. Expert for providing bacterial strains and manuscripts for our review. We also thank A. Van Buren for technical assistance, C. Wassell for figure preparations, and G. J. Feistner for manuscript review. This work was supported in part by Colorado Agricultural Experiment Station and by the Colorado Potato Administrative Committee.
Copyright 2007 Elsevier B.V., All rights reserved.
- Boronate affinity chromatography
- Erwinia carotovora