TY - JOUR
T1 - Conserved Microbial Toxicity Responses for Acute and Chronic Silver Nanoparticle Treatments in Wetland Mesocosms
AU - Ward, Christopher S.
AU - Pan, Jin Fen
AU - Colman, Benjamin P.
AU - Wang, Zhao
AU - Gwin, Carley A.
AU - Williams, Tiffany C.
AU - Ardis, Abby
AU - Gunsch, Claudia K.
AU - Hunt, Dana E.
N1 - Publisher Copyright:
Copyright © 2019 American Chemical Society.
PY - 2019/3/19
Y1 - 2019/3/19
N2 - Most studies of bacterial exposure to environmental contaminants focus on acute treatments; however, the impacts of single, high-dose exposures on microbial communities may not readily be extended to the more likely scenario of chronic, low-dose contaminant exposures. Here, in a year-long, wetland mesocosm experiment, we compared microbial community responses to pulse (single 450 mg dose of silver) and chronic (weekly 8.7 mg doses of silver for 1 year) silver nanoparticle (Ag0 NP) treatments, as well as a chronic treatment of "aged" sulfidized silver nanoparticles (Ag2S NPs). While mesocosms exposed to Ag2S NPs never differed significantly from the controls, both Ag0 NP treatments exhibited reduced microbial diversity and altered community composition; however, the effects differed in timing, duration, and magnitude. Microbial community-level impacts in the acute Ag0 NP treatment were apparent only within the first weeks and then converged on the control mesocosm composition, while chronic exposure effects were observed several months after exposures began, likely due to interactive effects of nanoparticle toxicity and winter environmental conditions. Notably, there was a high level of overlap in the taxa which exhibited significant declines (>10×) in both treatments, suggesting a conserved toxicity response for both pulse and chronic exposures. Thus, this research suggests that complex, but short-term, acute toxicological studies may provide critical, cost-effective insights into identifying microbial taxa sensitive to long-term chronic exposures to Ag NPs.
AB - Most studies of bacterial exposure to environmental contaminants focus on acute treatments; however, the impacts of single, high-dose exposures on microbial communities may not readily be extended to the more likely scenario of chronic, low-dose contaminant exposures. Here, in a year-long, wetland mesocosm experiment, we compared microbial community responses to pulse (single 450 mg dose of silver) and chronic (weekly 8.7 mg doses of silver for 1 year) silver nanoparticle (Ag0 NP) treatments, as well as a chronic treatment of "aged" sulfidized silver nanoparticles (Ag2S NPs). While mesocosms exposed to Ag2S NPs never differed significantly from the controls, both Ag0 NP treatments exhibited reduced microbial diversity and altered community composition; however, the effects differed in timing, duration, and magnitude. Microbial community-level impacts in the acute Ag0 NP treatment were apparent only within the first weeks and then converged on the control mesocosm composition, while chronic exposure effects were observed several months after exposures began, likely due to interactive effects of nanoparticle toxicity and winter environmental conditions. Notably, there was a high level of overlap in the taxa which exhibited significant declines (>10×) in both treatments, suggesting a conserved toxicity response for both pulse and chronic exposures. Thus, this research suggests that complex, but short-term, acute toxicological studies may provide critical, cost-effective insights into identifying microbial taxa sensitive to long-term chronic exposures to Ag NPs.
UR - http://www.scopus.com/inward/record.url?scp=85063152150&partnerID=8YFLogxK
U2 - 10.1021/acs.est.8b06654
DO - 10.1021/acs.est.8b06654
M3 - Article
C2 - 30776221
AN - SCOPUS:85063152150
SN - 0013-936X
VL - 53
SP - 3268
EP - 3276
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 6
ER -