[Thesis] Interactions of Engineered Nanoparticles with Biofilms and Selected Microorganisms in Model
The presence of engineered nanoparticles (ENPs) in the environment represents a potential risk to soil health, water safety and human health. Understanding the environmental transport and fate of ENPs is of paramount importance for the development and validation of regulatory guidelines regarding these new and increasingly prevalent materials. In addition, the safety of ENPs to organisms in the environment must be evaluated. Physical responses such as avoidance behavior are likely an indication of biological sensitivity to ENPs that merits further study. Experiments about the transport, fate and physical responses to ENPs were designed to address these knowledge gaps. First, traditional sand-packed columns were used in transport experiments to determine how ENPs interact with prevalent biomaterial, such as biofilms. Then, a quartz crystal microbalance with dissipation monitoring (QCM-D) was employed to assess biofilm-substrate interactions and the potential for physical responses in biofilms as a second objective. A microfluidic device for chemotaxis study, coupled with enhanced darkfield microscopy, was used to assess changes in swimming trajectory of organisms, a direct measure of physical responses following acute exposure to silver nanoparticles (nAg) and other ENP.
Michael R. Mitzel Doctor of Philosophy
Department of Natural Resources Sciences McGill School of Environment McGill University Montreal, Quebec, Canada December 2016 A thesis submitted to McGill University in partial fulfillment of the requirements of the degree of Doctor of Philosophy