Date of Award
8-2012
Document Type
Thesis
Degree Name
Master of Science (MS)
Legacy Department
Environmental Toxicology
Committee Chair/Advisor
Dr. Tamara L. McNealy
Committee Member
Dr. Stephen J. Klaine
Committee Member
Dr. Christopher L. Kitchens
Committee Member
Dr. J. Michael Henson
Abstract
An increase in the amount of money spent on nanotechnology has led to an increase in funding to support nanoparticle (NP) research. Due to their stable, beneficial properties, NPs are found in daily consumer products such as bike frames, socks, cosmetics, and sunscreens. As a result of this, these NPs have the potential to enter the environment and interact with various organisms that play integral roles in the ecosystem as a whole. The effect that NPs have on aquatic systems is largely unknown and understudied. Biofilms are an important structural and functional part of aquatic ecosystems, and comprise various microorganisms from bacteria to protozoa. NP use will increase the concentration of NPs in the environment, making them more likely to interact with biofilms. NP contamination of aquatic environments may lead to adverse effects on environmental organisms. Legionella pneumophila is a biofilm forming bacterium that can survive in a wide range of temperatures and pH. First, NPs were characterized in their stock solutions and the exposure media, moderately hard water (MHW). Biofilms were exposed to NPs with various core compositions and surface chemistries, and at two different concentrations. Changes in biofilm morphology, bio-volume and roughness coefficient were observed after exposure to low concentrations of 4 and 18 nm AuNPs, 4 nm PtNPs, and low and high concentrations of 8 nm Fe3O4 NPs. Larger 50 nm AuNPs, 8 nm AgNPs, or PSBs did not result in changes to the biofilm morphology. In addition, the number of viable cells being released from the biofilm after NP exposure increased as NP size and concentration decreased, but treatments were not statistically different from controls.
Recommended Citation
Raftery, Tara Diane, "Analysis of Nanoparticle Exposure on Legionella Pneumophila Biofilm Morphology and Host-Bacteria Interactions" (2012). All Theses. 2152.
https://open.clemson.edu/all_theses/2152