Biological role in the transformation of platinum-group mineral grains
Date
2016
Authors
Reith, F.
Zammit, C.
Shar, S.
Etschmann, B.
Bottrill, R.
Southam, G.
Ta, C.
Kilburn, M.
Oberthür, T.
Ball, A.
Editors
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Journal article
Citation
Nature Geoscience, 2016; 9(4):294-298
Statement of Responsibility
Frank Reith, Carla M. Zammit, Sahar S. Shar, Barbara Etschmann, Ralph Bottrill, Gordon Southam, Christine Ta, Matthew Kilburn, Thomas Oberthür, Andrew S. Ball and Joël Brugger
Conference Name
DOI
Abstract
Platinum-group elements are strategically important metals¹. Finding new deposits is becoming increasingly difficult owing to our limited understanding of the processes that affect their mobility in surface environments². Microorganisms have been shown to promote the mobility of metals around ore deposits³. Here we show that microorganisms influence the mobility of platinum-group elements in mineral grains collected from Brazil, Australia and Colombia. Scanning electron microscopy showed biofilms covering the platinum-group mineral grains. The biofilms contained abundant platinum-group element nanoparticles and microcrystalline aggregates, and were dominated by Proteobacteria,many of which were closely related to known metal-resistant species. Some platinum-group mineral grains contained carbon, nitrogen, sulfur, selenium and iodine, suggesting the grains may be biogenic in origin. Molecular analyses show that Brazilian platinum–palladium grains hosted specific bacterial communities, which were different in composition from communities associated with gold grains, or communities in surrounding soils and sediments. Nano-phase metallic platinum accumulated when a metallophillic bacterium was incubated with a percolating platinum-containing medium, suggesting that biofilms can cause the precipitation of mobile platinum complexes. We conclude that biofilms are capable of forming or transforming platinum-group mineral grains, and may play an important role for platinum-group element dispersion and re-concentration in surface environments.
School/Discipline
Dissertation Note
Provenance
Description
Access Status
Rights
© 2016 Macmillan Publishers Limited. All rights reserved