With an increasing utilization of nanoparticles (NPs) in consumer products, the potential for release to the environment also increases. It is therefore imperative that methods to test their potential effects in ecosystems are developed. This study describes an ex-situ methodology to gain a priori knowledge on the potential for NPs, or other possible emerging contaminants, to affect the catabolic capabilities of naturally occurring microbial communities. Microbial communities from a variety of sources were incubated with pre-specified carbon sources and National Institute of Standards and Technology (NIST) 10 nm gold nanoparticles (AuNPs) or an antibiotic, as a positive control, on 96 well micro-titre plates. From the results of the positive control study, dose response curves were used to assess the effect a toxicant can have on overall community catabolic capabilities and the communitys ability to assimilate or degrade specific carbon sources or groups of carbon sources. When adding 10 nm AuNPs at concentrations ranging from 0.01 to 0.5 µg/mL, rhizosphere communities from Typha roots were only slightly catabolically inhibited at a single concentration (0.05 µg/mL), no effects were seen on wetland water communities, and a minor positive (i.e. enhanced catabolic capabilities) effect was observed for loamy soil communities. This positive effect may be due to a thin layer of citrate found on these AuNPs which initiated co-metabolism with some of the carbon sources studied. Based upon the conditions studied the possible adverse effects of AuNPs on the catabolic capabilities of microbial communities appear to be minimal.
Proceedings Title: Micropol & Ecohazard 2013, the 8th IWA Specialist Conference on Assessment and Control of Micropollutants/Hazardous Substances in Water
Conference Dates: June 16-20, 2013
Conference Location: Zurich, -1
Pub Type: Conferences