Immobilisation of Platinum by Cupriavidus metallidurans

Minerals

Lachlan MacLean¹  Gordon Campbell²  Robert A. Gordon³  Dale Brewe³  Frank Reith⁴  Gordon Southam⁵ 

[1] Canadian Light Source, Saskatoon, SK S7N 2V3, Canada;Department of Earth Sciences, The University of Western Ontario, London, ON N6A 5B7, Canada;Pacific Northwest Consortium Synchrotron Radiation Facility, Advanced Photon Source, Argonne, IL 60439, USA;School of Biological Sciences, The Sprigg Geobiology Centre, The University of Adelaide, School of Biological Sciences, Adelaide, SA 5005, Australia;School of Earth and Environmental Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia;

关键词: geomicrobiology;    platinum;    Cupriavidus metallidurans;    biomineralisation;    synchrotron;   

DOI  :  10.3390/min8010010

来源: DOAJ

【 摘 要 】

The metal resistant bacterium Cupriavidus metallidurans CH34, challenged with aqueous platinous and platinic chloride, rapidly immobilized platinum. XANES/EXAFS analysis of these reaction systems demonstrated that platinum binding shifted from chloride to carboxyl functional groups within the bacteria. Pt(IV) was more toxic than Pt(II), presumably due to the oxidative stress imparted by the platinic form. Platinum immobilisation increased with time and with increasing concentrations of platinum. From a bacterial perspective, intracellular platinum concentrations were two to three orders of magnitude greater than the fluid phase, and became saturated at almost molar concentrations in both reaction systems. TEM revealed that C. metallidurans was also able to precipitate nm-scale colloidal platinum, primarily along the cell envelope where energy generation/electron transport occurs. Cells enriched in platinum shed outer membrane vesicles that were enriched in metallic, colloidal platinum, likely representing an important detoxification strategy. The formation of organo-platinum compounds and membrane encapsulated nanophase platinum, supports a role for bacteria in the formation and transport of platinum in natural systems, forming dispersion halos important to metal exploration.

【 授权许可】

Unknown