Impacts of Silver Nanoparticles on the Growth and Composition of Microorganisms Found in Natural and Engineered Systems

Monday, January 10, 2011

Presenter

Christina Arnaout

Abstract: Despite the beneficial applications of AgNPs in consumer products, their release into wastewater treatment plants and the downstream environment may negatively impact key microorganisms involved in nutrient removal. Consequently, it is important to characterize the effects of AgNPs in natural and engineered systems and to measure the antimicrobial effect of AgNPs on wastewater microorganisms. This presentation will discuss the antimicrobial potential of manufactured and laboratory made AgNPs and characterizes the effect of AgNPs on the ammonia oxidizing bacterium (AOB) Nitrosomonas europaea. Microbial growth inhibition was determined by exposing mixed and pure bacterial cultures to two different AgNPs (gum Arabic and polyvinylpyrrolidone) in concentrations ranging from 0.2 to 200 mg/L. In addition, microbial fingerprints were compared in the mixed community experiments. Silver concentrations were monitored by ICP-MS. Analyses being done on microbial communities from mesocosm experiments will also be briefly discussed.