A Novel In Situ Tool for the Exposure and Analysis of Microorganisms in Natural Aquatic Systems

Article Article scientifique Article A Novel In Situ Tool for the Exposure and Analysis of Microorganisms in Natural Aquatic Systems eng 2009 author Davis Thomas 626337 author Simon Dana Florina 557124 author Hassler Christel 60416 author Wilkinson Kevin 29725 8240-8244 10.1021/es901492y 0013-936X To evaluate the effects of contaminants or nutrient limitation in natural waters, it is often desirable to perform controlled exposures of organisms. While in situ exposures are routine for caged organisms or macrophytes, they are extremely difficult to perform for microorganisms, mainly due to difficulties in designinganexposure device that isolates the cells while allowing rapid equilibration with the external media. In this paper, a stirredunderwaterbiouptakesystem(SUBS)basedonthediffusion of chemicals across a semipermeable membrane housing a controlled population of microorganisms is reported. Cd diffusion through the semipermeable membrane was evaluated by voltammetry using a microelectrode. Comparison of stirred and unstirred solutions demonstrated a significantly increased diffusive flux in the presence of stirring. Lab tests using Chlamydomonas reinhardtii showed that diffusion across the semipermeable membrane was not limiting with respect to the biouptake of Cd. The SUBS device was field tested and the results of viability studies and trace metal biouptake by C. reinhardtii are reported. No diffusion limitation due to the SUBS was observed for Cd under the tested field conditions. The SUBS device was also shown to be useful for field exposures and subsequent measurements of trace metal uptake and viability. The results support the future use of the SUBS for the in situmeasurementof phytochelatin/metallothionein production, photosynthetic efficiency, or reporter gene induction of controlled organisms. Dewey 550 41 Département F.-A. Forel des sciences de l'environnement et de l'eau 153 false 758 Marine and Lake Geochemistry Environmental science & technology 43 21 3671faad-535f-4630-8aea-42c32bcd864a Article (Published version) Restricted Davisetal2009.pdf 502458 application/pdf restrictedAccess Faculté des sciences / Section des sciences de la Terre et de l'Environnement / Département F.-A. Forel des sciences de l'environnement et de l'eau

Title	Published in	Access level	OA Policy	Year	Views	Downloads

A Novel In Situ Tool for the Exposure and Analysis of Microorganisms in Natural Aquatic Systems	Environmental science & technology			2009	648	1

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Davis, Thomas