AQDS Activates Extracellular Synergistic Biodetoxification of Copper and Selenite via Altering the Coordination Environment of Outer-Membrane Proteins.
Environ Sci Technol
; 56(19): 13786-13797, 2022 10 04.
Article
em En
| MEDLINE
| ID: mdl-36098667
ABSTRACT
The biotransformation of heavy metals in the environment is usually affected by co-existing pollutants like selenium (Se), which may lower the ecotoxicity of heavy metals, but the underlying mechanisms remain unclear. Here, we shed light on the pathways of copper (Cu2+) and selenite (SeO32-) synergistic biodetoxification by Shewanella oneidensis MR-1 and illustrate how such processes are affected by anthraquinone-2,6-disulfonate (AQDS), an analogue of humic substances. We observed the formation of copper selenide nanoparticles (Cu2-xSe) from synergistic detoxification of Cu2+ and SeO32- in the periplasm. Interestingly, adding AQDS triggered a fundamental transition from periplasmic to extracellular reaction, enabling 14.7-fold faster Cu2+ biodetoxification (via mediated electron transfer) and 11.4-fold faster SeO32- detoxification (via direct electron transfer). This is mainly attributed to the slightly raised redox potential of the heme center of AQDS-coordinated outer-membrane proteins that accelerates electron efflux from the cells. Our work offers a fundamental understanding of the synergistic detoxification of heavy metals and Se in a complicated environmental matrix and unveils an unexpected role of AQDS beyond electron mediation, which may guide the development of more efficient environmental remediation and resource recovery biotechnologies.
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Base de dados:
MEDLINE
Assunto principal:
Selênio
/
Poluentes Ambientais
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article