PMID- 25556815
OWN - NLM
STAT- MEDLINE
DCOM- 20151109
LR  - 20181202
IS  - 1552-8618 (Electronic)
IS  - 0730-7268 (Linking)
VI  - 34
IP  - 4
DP  - 2015 Apr
TI  - Planktonic and biofilm-grown nitrogen-cycling bacteria exhibit different 
      susceptibilities to copper nanoparticles.
PG  - 887-97
LID - 10.1002/etc.2867 [doi]
AB  - Proper characterization of nanoparticle (NP) interactions with environmentally 
      relevant bacteria under representative conditions is necessary to enable their 
      sustainable manufacture, use, and disposal. Previous nanotoxicology research 
      based on planktonic growth has not adequately explored biofilms, which serve as 
      the predominant mode of bacterial growth in natural and engineered environments. 
      Copper nanoparticle (Cu-NP) impacts on biofilms were compared with respective 
      planktonic cultures of the ammonium-oxidizing Nitrosomonas europaea, 
      nitrogen-fixing Azotobacter vinelandii, and denitrifying Paracoccus denitrificans 
      using a suite of independent toxicity diagnostics. Median inhibitory 
      concentration (IC50) values derived from adenosine triphosphate (ATP) for Cu-NPs 
      were lower in N. europaea biofilms (19.6 +/- 15.3 mg/L) than in planktonic cells 
      (49.0 +/- 8.0 mg/L). However, in absorbance-based growth assays, compared with 
      unexposed controls, N. europaea growth rates in biofilms were twice as resilient 
      to inhibition than those in planktonic cultures. Similarly, relative to unexposed 
      controls, growth rates and yields of P. denitrificans in biofilms exposed to 
      Cu-NPs were 40-fold to 50-fold less inhibited than those in planktonic cells. 
      Physiological evaluation of ammonium oxidation and nitrate reduction suggested 
      that biofilms were also less inhibited by Cu-NPs than planktonic cells. 
      Furthermore, functional gene expression for ammonium oxidation (amoA) and nitrite 
      reduction (nirK) showed lower inhibition by NPs in biofilms relative to 
      planktonic-grown cells. These results suggest that biofilms mitigate NP impacts, 
      and that nitrogen-cycling bacteria in wastewater, wetlands, and soils might be 
      more resilient to NPs than planktonic-based assessments suggest.
CI  - (c) 2014 SETAC.
FAU - Reyes, Vincent C
AU  - Reyes VC
AD  - Department of Civil and Environmental Engineering, University of California, Los 
      Angeles, California, USA.
FAU - Opot, Stephen O
AU  - Opot SO
FAU - Mahendra, Shaily
AU  - Mahendra S
LA  - eng
PT  - Journal Article
PT  - Research Support, U.S. Gov't, Non-P.H.S.
DEP - 20150302
PL  - United States
TA  - Environ Toxicol Chem
JT  - Environmental toxicology and chemistry
JID - 8308958
RN  - 0 (Ammonium Compounds)
RN  - 0 (Environmental Pollutants)
RN  - 0 (Nitrates)
RN  - 789U1901C5 (Copper)
SB  - IM
MH  - Ammonium Compounds/metabolism
MH  - Azotobacter vinelandii/drug effects/growth & development
MH  - Bacteria/*drug effects/*growth & development
MH  - Biofilms/*growth & development
MH  - Copper/*toxicity
MH  - Environmental Pollutants/*toxicity
MH  - Gene Expression Regulation, Bacterial/drug effects
MH  - Metal Nanoparticles/*toxicity
MH  - Nitrates/metabolism
MH  - *Nitrogen Fixation
MH  - Nitrosomonas europaea/drug effects/growth & development
MH  - Oxidation-Reduction
MH  - Paracoccus denitrificans/drug effects/growth & development
MH  - Plankton/*microbiology
OTO - NOTNLM
OT  - Extracellular polymeric substances
OT  - Metallic
OT  - Nanomaterials
OT  - Stress
EDAT- 2015/01/06 06:00
MHDA- 2015/11/10 06:00
CRDT- 2015/01/06 06:00
PHST- 2014/08/15 00:00 [received]
PHST- 2014/12/16 00:00 [revised]
PHST- 2014/12/19 00:00 [accepted]
PHST- 2015/01/06 06:00 [entrez]
PHST- 2015/01/06 06:00 [pubmed]
PHST- 2015/11/10 06:00 [medline]
AID - 10.1002/etc.2867 [doi]
PST - ppublish
SO  - Environ Toxicol Chem. 2015 Apr;34(4):887-97. doi: 10.1002/etc.2867. Epub 2015 Mar 
      2.