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Common freshwater bacteria vary in their responses to short‐term exposure to nano‐TiO 2
Author(s) -
Binh Chu Thi Thanh,
Tong Tiezheng,
Gaillard JeanFrançois,
Gray Kimberly A.,
Kelly John J.
Publication year - 2014
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.2442
Subject(s) - environmental chemistry , bacteria , nano , natural organic matter , chemistry , nanomaterials , organic matter , biology , ecology , nanotechnology , chemical engineering , materials science , genetics , engineering
Nanostructured titania (nano‐TiO 2 ) is an engineered nanomaterial that can be cytotoxic primarily as a result of its ability to generate reactive oxygen species when illuminated. Production of nano‐TiO 2 has increased rapidly over the last decade, leading to concerns about its release into aquatic environments. To address the possible ecological impacts of nano‐TiO 2 , the authors used high‐throughput screening to assess the responses of 4 bacteria representative of genera common in freshwater to short‐term exposure (1–2 h) in 2 natural aqueous media (stream water and lake water) to 2 widely used TiO 2 products, pigment white 6 (PW6) and P25. Under simulated solar illumination PW6 and P25 reduced the abundance of viable Bacillus subtilis and Aeromonas hydrophila , confirming the cytotoxicity of nano‐TiO 2 . In contrast, PW6 and P25 stimulated growth of Arthrobacter sp. and Klebsiella sp., which the authors hypothesize was driven by oxidation of organic matter in these natural waters into more labile compounds. This hypothesis is supported by data demonstrating PW6 photo‐oxidation of organic matter in stream water, which subsequently supported enhanced bacterial growth. The results indicate that bacterial responses to nano‐TiO 2 can be species‐specific, suggesting that nano‐TiO 2 may alter bacterial community composition and function. Finally, the results indicate that bacterial responses to nano‐TiO 2 are influenced by the water matrix, emphasizing the importance of assessing bacterial responses to nanomaterials in natural environmental media. Environ Toxicol Chem 2014;33:317–327. © 2013 SETAC