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Title: Separation of Bacteria, Protozoa and Carbon Nanotubes by Density Gradient Centrifugation

Journal Article · · Nanomaterials
DOI:https://doi.org/10.3390/nano6100181· OSTI ID:1377787
 [1];  [2];  [3];  [4]
  1. Univ. of California, Santa Barbara, CA (United States). Bren School of Environmental Science and Management, Earth Research Inst., and Center for the Environmental Implications of Nanotechnology; National Institute of Chemical Physics and Biophysics, Tallinn (Estonia). Lab. of Environmental Toxicology
  2. National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States). Biosystems and Biomaterials Division, Material Measurement Lab.
  3. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  4. Univ. of California, Santa Barbara, CA (United States). Bren School of Environmental Science and Management, Earth Research Inst., and Center for the Environmental Implications of Nanotechnology

Sustainable production and use of carbon nanotube (CNT)-enabled materials require efficient assessment of CNT environmental hazards, including the potential for CNT bioaccumulation and biomagnification in environmental receptors. Microbes, as abundant organisms responsible for nutrient cycling in soil and water, are important ecological receptors for studying the effects of CNTs. Quantification of CNT association with microbial cells requires efficient separation of CNT-associated cells from individually dispersed CNTs and CNT agglomerates. Here in this paper, we designed, optimized, and demonstrated procedures for separating bacteria (Pseudomonas aeruginosa) from unbound multiwall carbon nanotubes (MWCNTs) and MWCNT agglomerates using sucrose density gradient centrifugation. We demonstrate separation of protozoa (Tetrahymena thermophila) from MWCNTs, bacterial agglomerates, and protozoan fecal pellets by centrifugation in an iodixanol solution. The presence of MWCNTs in the density gradients after centrifugation was determined by quantification of 14C-labeled MWCNTs; the recovery of microbes from the density gradient media was confirmed by optical microscopy. Protozoan intracellular contents of MWCNTs and of bacteria were also unaffected by the designed separation process. Lastly, the optimized methods contribute to improved efficiency and accuracy in quantifying MWCNT association with bacteria and MWCNT accumulation in protozoan cells, thus supporting improved assessment of CNT bioaccumulation.

Research Organization:
Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
Sponsoring Organization:
USDOE: National Science Foundation (NSF); USEPA; Estonian Research Council
Grant/Contract Number:
AC52-07NA27344; PUTJD16
OSTI ID:
1377787
Report Number(s):
LLNL-JRNL-684658; NANOKO; PII: nano6100181
Journal Information:
Nanomaterials, Vol. 6, Issue 10; ISSN 2079-4991
Publisher:
MDPICopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 15 works
Citation information provided by
Web of Science

References (44)

Ecological Nanotoxicology: Integrating Nanomaterial Hazard Considerations Across the Subcellular, Population, Community, and Ecosystems Levels journal July 2012
Exposure to CuO Nanoparticles Changes the Fatty Acid Composition of Protozoa Tetrahymena thermophila journal August 2011
A simple separation method for downstream biochemical analysis of aquatic microbes journal April 2015
“Density equilibrium” method for the quantitative and rapid in situ determination of lipid, hydrocarbon, or biopolymer content in microorganisms journal April 2009
The effects of high energy probe sonication on the thermoelectric power of large diameter multiwalled carbon nanotubes synthesized by chemical vapor deposition journal November 2013
Toxicity of 12 metal-based nanoparticles to algae, bacteria and protozoa journal January 2015
Use of the Sucrose Gradient Method for Bacterial Cell Cycle Synchronization journal May 2012
Five reasons to use bacteria when assessing manufactured nanomaterial environmental hazards and fates journal June 2014
Carbon nanotube clusters as universal bacterial adsorbents and magnetic separation agents journal January 2009
Quantification of Carbon Nanotubes in Environmental Matrices: Current Capabilities, Case Studies, and Future Prospects journal April 2016
Effects of TiO 2 and Ag Nanoparticles on Polyhydroxybutyrate Biosynthesis By Activated Sludge Bacteria journal November 2014
Bacterial remediation from effluent containing multi-walled carbon nanotubes journal July 2011
Iodixanol: A Nonionic Iso-osmotic Centrifugation Medium for the Formation of Self-Generated Gradients journal August 1994
Determination of nanoparticle size distribution together with density or molecular weight by 2D analytical ultracentrifugation journal June 2011
Bulk enrichment and separation of multi-walled carbon nanotubes by density gradient centrifugation journal May 2009
Bioaccumulation of Multiwall Carbon Nanotubes in Tetrahymena thermophila by Direct Feeding or Trophic Transfer journal July 2016
Carbon nanotube compared with carbon black: effects on bacterial survival against grazing by ciliates and antimicrobial treatments journal January 2012
Bioaccumulation of Radio-Labeled Carbon Nanotubes by Eisenia foetida journal April 2008
Relevance of octanol-water distribution measurements to the potential ecological uptake of multi-walled carbon nanotubes journal January 2010
High performance separation of aerosol sprayed mesoporous TiO2 sub-microspheres from aggregates via density gradient centrifugation journal January 2010
Uptake, localization and clearance of quantum dots in ciliated protozoa Tetrahymena thermophila journal July 2014
Degradation of multiwall carbon nanotubes by bacteria journal October 2013
Ultrasonic dispersion of nanoparticles for environmental, health and safety assessment – issues and recommendations journal September 2010
Sucrose density gradient centrifugation separation of gold and silver nanoparticles synthesized using Magnolia kobus plant leaf extracts journal February 2014
Plasmolysis and Cell Shape Depend on Solute Outer-Membrane Permeability during Hyperosmotic Shock in E. coli journal June 2013
Effects of Soluble Cadmium Salts Versus CdSe Quantum Dots on the Growth of Planktonic Pseudomonas aeruginosa journal April 2009
Colloidal stability and ecotoxicity of multiwalled carbon nanotubes: Influence of select organic matters: Nanomaterials in the environment journal November 2015
Dispersion of TiO2 Nanoparticle Agglomerates by Pseudomonas aeruginosa journal September 2010
Analytical Protocols for Separation and Electron Microscopy of Nanoparticles Interacting with Bacterial Cells journal April 2015
Use of Tetrahymena thermophila To Study the Role of Protozoa in Inactivation of Viruses in Water journal November 2006
Effects of Graphene Oxide and Oxidized Carbon Nanotubes on the Cellular Division, Microstructure, Uptake, Oxidative Stress, and Metabolic Profiles journal July 2015
Evaluation of toxicity of nanoclays and graphene oxide in vivo: a Paramecium caudatum study journal January 2016
Interactions of multiwalled carbon nanotubes with algal cells: Quantification of association, visualization of uptake, and measurement of alterations in the composition of cells journal January 2015
Phase Distribution of 14 C-Labeled Multiwalled Carbon Nanotubes in Aqueous Systems Containing Model Solids: Peat journal February 2011
Isolation of exosomes by differential centrifugation: Theoretical analysis of a commonly used protocol journal November 2015
Toxicity of ZnO and CuO nanoparticles to ciliated protozoa Tetrahymena thermophila journal March 2010
NanoE-Tox: New and in-depth database concerning ecotoxicity of nanomaterials journal January 2015
Adaptive Interactions between Zinc Oxide Nanoparticles and Chlorella sp. journal October 2012
Biomagnification of cadmium selenide quantum dots in a simple experimental microbial food chain journal December 2010
Nanomaterials in Agricultural Production: Benefits and Possible Threats? book January 2013
Differential Growth of and Nanoscale TiO 2 Accumulation in Tetrahymena thermophila by Direct Feeding versus Trophic Transfer from Pseudomonas aeruginosa journal July 2013
Separation of small ciliate protozoa from bacteria by sucrose gradient centrifugation. journal January 1976
Assessing the Role of Pseudomonas aeruginosa Surface-Active Gene Expression in Hexadecane Biodegradation in Sand journal May 2002
Enhanced Exopolymer Production and Chromium Stabilization in Pseudomonas putida Unsaturated Biofilms journal March 2006

Cited By (3)

Challenges in characterizing the environmental fate and effects of carbon nanotubes and inorganic nanomaterials in aquatic systems journal January 2018
Strategies for robust and accurate experimental approaches to quantify nanomaterial bioaccumulation across a broad range of organisms journal January 2019
Challenges in characterizing the environmental fate and effects of carbon nanotubes and inorganic nanomaterials in aquatic systems text January 2018