title: Platinum Recovery from Synthetic Extreme Environments by Halophilic Bacteria.
abstract: Metal recycling based on urban mining needs to be established to tackle the increasing supply risk of critical metals such as platinum. Presently, efficient strategies are missing for the recovery of platinum from diluted industrial process streams, often characterized by extremely low pHs and high salt concentrations. In this research, halophilic mixed cultures were employed for the biological recovery of platinum (Pt). Halophilic bacteria were enriched from Artemia cysts, living in salt lakes, in different salt matrices (sea salt mixture and NH4Cl; 20-210 g L(-1) salts) and at low to neutral pH (pH 3-7). The main taxonomic families present in the halophilic cultures were Halomonadaceae, Bacillaceae, and Idiomarinaceae. The halophilic cultures were able to recover >98% Pt(II) and >97% Pt(IV) at pH 2 within 3-21 h (4-453 mg Ptrecovered h(-1) g(-1) biomass). X-ray absorption spectroscopy confirmed the reduction to Pt(0) and transmission electron microscopy revealed both intra- and extracellular Pt precipitates, with median diameters of 9-30 nm and 11-13 nm, for Pt(II) and Pt(IV), respectively. Flow cytometric membrane integrity staining demonstrated the preservation of cell viability during platinum recovery. This study demonstrates the Pt recovery potential of halophilic mixed cultures in acidic saline conditions.
authors: Laboratory of Microbial Ecology and Technology (LabMET), Ghent University , Coupure Links 653, B-9000 Gent, Belgium.
authors: Synthia
authors: S
authors: Maes
authors: Laboratory of Microbial Ecology and Technology (LabMET), Ghent University , Coupure Links 653, B-9000 Gent, Belgium.
authors: Ruben
authors: R
authors: Props
authors: Department of Civil and Environmental Engineering, Princeton University , Princeton, New York 08544, United States.
authors: Jeffrey P
authors: JP
authors: Fitts
authors: Department of Medical and Forensic Pathology, Ghent University , De Pintelaan 185, B-9000 Gent, Belgium.
authors: Rebecca De
authors: RD
authors: Smet
authors: Laboratory of Microbial Ecology and Technology (LabMET), Ghent University , Coupure Links 653, B-9000 Gent, Belgium.
authors: Ramiro
authors: R
authors: Vilchez-Vargas
authors: Microbial Interactions and Processes Research Group, Department of Medical Microbiology, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany.
authors: Marius
authors: M
authors: Vital
authors: Microbial Interactions and Processes Research Group, Department of Medical Microbiology, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany.
authors: Dietmar H
authors: DH
authors: Pieper
authors: Department of Analytical Chemistry, Ghent University , Krijgslaan 281 (S12), B-9000 Gent, Belgium.
authors: Frank
authors: F
authors: Vanhaecke
authors: Laboratory of Microbial Ecology and Technology (LabMET), Ghent University , Coupure Links 653, B-9000 Gent, Belgium.
authors: Nico
authors: N
authors: Boon
authors: Laboratory of Microbial Ecology and Technology (LabMET), Ghent University , Coupure Links 653, B-9000 Gent, Belgium.
authors: Tom
authors: T
authors: Hennebel
mesh_terms: D000818:Animals; D001156:Artemia; D001419:Bacteria / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D018533:Biomass; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D011232:Chemical Precipitation; D004777:Environment; D010984:Platinum / Q000302:isolation & purification*; D012965:Sodium Chloride / Q000494:pharmacology*; D056928:X-Ray Absorption Spectroscopy
chemical_list: D012965:Sodium Chloride; D010984:Platinum