HR: 10:40h
AN: B32A-02    [Abstracts]
TI: Bacterial Interactions with CdSe Quantum Dots
AU: Holden, P
EM: holden@bren.ucsb.edu
AF: Univ. of California, Santa Barbara, Donald Bren School of Environmental Science & Management, Santa Barbara, CA 93106, United States
AU: * Nadeau, J L
EM: jay.nadeau@mcgill.ca
AF: McGill Univeristy, Biomedical Engineering, Montreal, QC H3A2B4, Canada
AU: Kumar, A
EM: anil.sureshkumar@gmail.com
AF: McGill Univeristy, Biomedical Engineering, Montreal, QC H3A2B4, Canada
AU: Clarke, S
EM: samuel.clarke@mail.mcgill.ca
AF: McGill Univeristy, Biomedical Engineering, Montreal, QC H3A2B4, Canada
AU: Priester, J H
EM: jprieste@bren.ucsb.edu
AF: Univ. of California, Santa Barbara, Donald Bren School of Environmental Science & Management, Santa Barbara, CA 93106, United States
AU: Stucky, G D
EM: stucky@chem.ucsb.edu
AF: Univ. of California, Santa Barbara, Department of Chemistry and Biochemistry, Santa Barbara, CA 93106, United States
AB: Cadmium selenide quantum dots (QDs) are semiconductor nanoparticles that are manufactured for biomedical imaging, photovoltaics, and other applications. While metallic nanoparticles can be made biotically by bacteria and fungi, and thus occur in nature, the fate of either natural or engineered QDs and relationships to nanoparticle size, conjugate and biotic conditions are mostly unknown. Working with several different bacterial strains and QDs of different sizes and conjugate chemistries, including QDs synthesized by a Fusarium fungal strain, we show that QDs can enter cells through specfic receptor-mediated processes, that QDs are broken down by bacteria during cell association, and that toxicity to cells is much like that imposed by Cd(II) ions. The mechanisms of entry and toxicity are not fully understood, but preliminary evidence suggests that electron transfer between cells and QDs occurs. Also, cell membranes are compromised, indicating oxidative stress is occurring. Results with planktonic and biofilm bacteria are similar, but differently, biofilms tend to accumulate Cd(II) associated with QD treatments.
DE: 0448 Geomicrobiology
DE: 0461 Metals
DE: 0463 Microbe/mineral interactions
DE: 0465 Microbiology: ecology, physiology and genomics (4840)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting