Microbial biominers: Sequential bioleaching and biouptake of metals from electronic scraps

The article shows the potential of a microbial sequential process to revalorize electronic scraps and recover metals and rare earth elements harnessing extremotolerant microorganisms. AbstractElectronic scraps (e-scraps) represent an attractive raw material to mine demanded metals, as well as rare earth elements (REEs). A sequential microbial-mediated process developed in two steps was examined to recover multiple elements. First, we made use of an acidophilic bacteria consortium, mainly composed ofAcidiphilium multivorum andLeptospidillum ferriphilum, isolated from acid mine drainages. The consortium was inoculated in a dissolution of e-scraps powder and cultured for 15 days. Forty-five elements were analyzed in the liquid phase over time, including silver, gold, and 15 REEs. The bioleaching efficiencies of the consortium were>99% for Cu, Co, Al, and Zn, 53% for Cd, and around 10% for Cr and Li on Day 7. The second step consisted of a microalgae-mediated uptake from e-scraps leachate. The strains used were two acidophilic extremotolerant microalgae,Euglena sp. (EugVP) andChlamydomonas sp. (ChlSG) strains, isolated from the same extreme environment. Up to 7.3, 4.1, 1.3, and 0.7  µg by wet biomass (WB) of Zn, Al, Cu, and Mn, respectively, were uptaken by ChlSG biomass in 12 days, presenting higher efficiency than EugVP. Concerning REEs, ChlSG biouptake 14.9, 20.3, 13.7, 8.3 ng of Gd, Pr, Ce, La per WB. Meanwhile, EugVP captured 1.1, 1.5, 1.4, and 7.5, respectively. Thi...
Source: MicrobiologyOpen - Category: Microbiology Authors: Tags: ORIGINAL ARTICLE Source Type: research