This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Renshaw, J. C. Articles by Taylor, R. J. Search for Related Content PubMed PubMed Citation Articles by Renshaw, J. C. Articles by Taylor, R. J. Agricola Articles by Renshaw, J. C. Articles by Taylor, R. J.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, June 2003, p. 3600-3606, Vol. 69, No. 6
0099-2240/03/$08.00+0     DOI: 10.1128/AEM.69.6.3600-3606.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

Development and Application of an Assay for Uranyl Complexation by Fungal Metabolites, Including Siderophores

Joanna C. Renshaw,^1* Verity Halliday,² Geoffrey D. Robson,² Anthony P. J. Trinci,² Marilyn G. Wiebe,³ Francis R. Livens,¹ David Collison,⁴ and Robin J. Taylor⁵

Centre for Radiochemistry Research, Department of Chemistry,¹ Department of Chemistry, The University of Manchester, Manchester M13 9PT,⁴ School of Biological Sciences, The University of Manchester, Manchester M13 9PL,² Research and Technology, British Nuclear Fuels Ltd., Sellafield, Seascale, Cumbria CA20 1PG, United Kingdom,⁵ Institute of Life Sciences, Aalborg University, DK-9000 Aalborg, Denmark³

Received 9 December 2002/ Accepted 20 March 2003

An assay to detect UO₂²⁺ complexation was developed based on the chrome azurol S (CAS) assay for siderophores (B. Schwyn and J. B. Neilands, Anal. Biochem. 160:47-56, 1987) and was used to investigate the ability of fungal metabolites to complex actinides. In this assay the discoloration of two dyed agars (one containing a CAS-Fe³⁺ dye and the other containing a CAS-UO₂²⁺ dye) caused by ligands was quantified. The assay was tested by using the siderophore desferrioxamine B (DFO), and the results showed that there was a regular, reproducible relationship between discoloration and the amount of siderophore added. The ratio of the discoloration on the CAS-UO₂²⁺ agar to the discoloration on the CAS-Fe³⁺ agar was independent of the amount of siderophore added. A total of 113 fungi and yeasts were isolated from three soil samples taken from the Peak District National Park. The fungi were screened for the production of UO₂²⁺ chelators by using the CAS-based assay and were also tested specifically for hydroxamate siderophore production by using the hydroxamate siderophore auxotroph Aureobacterium flavescens JG-9. This organism is highly sensitive to the presence of hydroxamate siderophores. However, the CAS-based assay was found to be less sensitive than the A. flavescens JG-9 assay. No significant difference between the results for each site for the two tests was found. Three isolates were selected for further study and were identified as two Pencillium species and a Mucor species. Our results show that the new assay can be effectively used to screen fungi for the production of UO₂²⁺ chelating ligands. We suggest that hydroxamate siderophores can be produced by mucoraceous fungi.

---

* Corresponding author. Mailing address: Centre for Radiochemistry Research, Department of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PT, United Kingdom. Phone: (44) 0161 275 1405. Fax: (44) 0161 275 4598. E-mail: joanna.c.renshaw{at}man.ac.uk.

---

Applied and Environmental Microbiology, June 2003, p. 3600-3606, Vol. 69, No. 6
0099-2240/03/$08.00+0     DOI: 10.1128/AEM.69.6.3600-3606.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

This article has been cited by other articles:

• Braud, A., Hannauer, M., Mislin, G. L. A., Schalk, I. J. (2009). The Pseudomonas aeruginosa Pyochelin-Iron Uptake Pathway and Its Metal Specificity. J. Bacteriol. 191: 3517-3525 [Abstract] [Full Text]