1. Induced accumulation of Au, Ag and Cu in Brassica napus grown in a mine tailings with the inoculation of Aspergillus niger and the application of two chemical compounds.
- Author
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González-Valdez E, Alarcón A, Ferrera-Cerrato R, Vega-Carrillo HR, Maldonado-Vega M, Salas-Luévano MÁ, and Argumedo-Delira R
- Subjects
- Aspergillus niger physiology, Brassica napus drug effects, Brassica napus microbiology, Plant Leaves metabolism, Plant Roots metabolism, Thiocyanates pharmacology, Thiosulfates pharmacology, Brassica napus metabolism, Copper metabolism, Gold metabolism, Mining, Silver metabolism
- Abstract
This study evaluated the ability of Brassica napus for extracting gold (Au), silver (Ag) and copper (Cu) from a mine tailings, with the inoculation of two Aspergillus niger strains, and the application of ammonium thiocyanate (NH
4 SCN) or ammonium thiosulfate [(NH4 )2 S2 O3 ]. After seven weeks of growth inoculated or non-inoculated plants were applied with 1 or 2 g kg-1 of either NH4 SCN or (NH4 )2 S2 O3 , respectively. Eight days after the application of the chemical compounds, plants were harvested for determining the total dry biomass, and the content of Au, Ag, and Cu in plant organs. Application of (NH4 )2 S2 O3 or NH4 SCN resulted in enhanced Au-accumulation in stems (447% and 507%, respectively), while either (NH4 )2 S2 O3 +Aspergillus, or NH4 SCN increased the Au-accumulation in roots (198.5% and 404%, respectively) when compared to the control. Treatments with (NH4 )2 S2 O3 or (NH4 )2 S2 O3 +Aspergillus significantly increased (P ≤ 0.001) the accumulation of Ag in leaves (677% and 1376%, respectively), while NH4 SCN + Aspergillus, and (NH4 )2 S2 O3 enhanced the accumulation in stems (7153% and 6717.5%). The Ag-accumulation in roots was stimulated by NH4 SCN+ Aspergillus, and (NH4 )2 S2 O3 + Aspergillus (132.5% and 178%, respectively), when compared to the control. The combination of NH4 SCN+Aspergillus significantly enhanced the Cu-accumulation in leaves (228%); whereas NH4 SCN+ Aspergillus, or (NH4 )2 S2 O3 + Aspergillus resulted in greater accumulation of Cu in stems (1233.5% and 1580%, respectively) than the control. Results suggest that either NH4 SCN or (NH4 )2 S2 O3 (with or without Aspergillus) improved the accumulation of Au and Ag by B. napus. Accumulation of Au and Ag in plant organs overpassed the hyperaccumulation criterion (> 1 mg kg-1 of plant biomass); whereas Cu-accumulation in stems and roots also overpassed such criterion (> 1000 mg kg-1 ) by applying either NH4 SCN or (NH4 )2 S2 O3 + A. niger., (Copyright © 2018 Elsevier Inc. All rights reserved.)- Published
- 2018
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