Grantee Research Project Results
Differential Environmental Impact of Size-varied NanomaterialsEPA Grant Number: F5D20713
Title: Differential Environmental Impact of Size-varied Nanomaterials
Investigators: Lyon, Delina Y.
Institution: Rice University
EPA Project Officer: Lee, Sonja
Project Period: August 1, 2005 through September 30, 2006
Project Amount: $111,172
RFA: STAR Graduate Fellowships (2005) RFA Text | Recipients Lists
Research Category: Academic Fellowships
The primary objective of this research is to observe how nanomaterials affect environmental systems using bacteria as environmental indicators. Variable-sized titanium dioxide, zinc oxide, silicon dioxide, and fullerene will be exposed to bacteria, and the mechanisms behind any observed antibacterial activity will be investigated. Additonally, this research aims to assess possible applications for these nanomaterials as water disinfectants or anti-biofilm coatings.
Escherichia coli and Bacillus subtilis will be exposed to different sizes of titanium dioxide, zinc oxide, silicon dioxide, and fullerene suspensions and monitored for cell respiration and growth. The nanomaterials will also be introduced into soil columns (simulating a spill) to observe interactions of the particles with soil and the microbiota. Any changes in the soil microbial community will be monitored using real-time quantitative PCR (RT-PCR) complemented with denaturing gradient gel electrophoresis (DGGE). Soil health will also be tracked by assaying for important soil enzymes, such as hydrolases and oxidoreductases. The mechanisms behind any observed antibacterial activity will be investigated by comparing responses of different bacterial species, observing the physiology of bacteria before and after exposure, and quantifying reactive oxygen species (ROS) generation. These observations will help determine if these nanomaterials make suitable disinfectants or anti-biofilm coatings.
This research will help predict the behavior of nanomaterials after its release into the environment and what precautions might be necessary in working with nanomaterials. The possibility of using nanomaterials as bactericidal agents will also be investigated.