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Interactions of core-shell quantum dots with metal resistant bacterium Cupriavidus metallidurans: Consequences for Cu and Pb removal
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Orientador(es)
Resumo(s)
In the present study we address the interactions of carboxyl-CdSe/ZnS core/shell quantum dots (QDs),as a model of water dispersible engineered nanoparticles, and metal resistant bacteria Cupriavidusmetallidurans, largely used in metal decontamination. The results demonstrate that QDs with averagehydrodynamic size of 12.9 nm adhere to C. metallidurans. The percentage of bacterial cells displayingQD-fluorescence increased proportionally with contact time and QD concentration in bacterial mediumdemonstrating the association of QDs with the metal resistant bacteria. No evidence of QD internalizationinto bacterial cytoplasm was found by transmission electron microscopy with energy dispersive X-rayspectrometry, however QD clusters of sizes between 20 and 50 nm were observed on the bacterial sur-face and in the bacterial periplasmic compartment; observations consistent with the losses of membraneintegrity induced by QDs. The presence of 20 nM QDs induced about 2-fold increase in Cu and Pb uptakefluxes by C. metallidurans exposed to 500 nM Pb or Cu, respectively. Overall, the results of this work sug-gest that when present in mixture with Cu and Pb, low levels of QDs originating from possible incidentalrelease or QD disposal could increase metal accumulation in metal resistant bacterium.
Descrição
Palavras-chave
Quantum dots Bioremediation Metal uptake Bacteriaa
Contexto Educativo
Citação
Slaveykova, V. I.; Pinheiro, J. P.; Floriani, M.; Garcia, M. Interactions of core-shell quantum dots with metal resistant bacterium Cupriavidus metallidurans: Consequences for Cu and Pb removal, Journal of Hazardous Materials, 261, 261, 123-129, 2013.
Editora
Elsevier