Regensburg 2016 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 39: Biomaterials and Biopolymers I (joint session CPP/BP/MM)
MM 39.7: Talk
Wednesday, March 9, 2016, 17:00–17:15, H40
Impact of Silver Nanoparticles on the mechanical properties of Aquabacterium biofilms — •Yvonne Schmitt1, Alexandra Grün1, Dimitri Demeshko2, Werner Manz1, and Silke Rathgeber1,2 — 1Institute for Natural Sciences, University of Koblenz-Landau, Koblenz, Germany. — 2Technology Institute for Functional Polymers and Surfaces (tifko) GmbH, Neuwied, Germany.
The antimicrobial properties of silver nanoparticles (AgNP) led to a wide range of applications in consumer products. As a consequence, there is an increasing release of AgNP into aquatic environments. Biofilms, a conglomerate of extracellular DNA, polysaccharides and proteins, play an important role in sediment stabilization in riverine systems. AgNP are supposed to be a continuous source for silver ions (Ag+) which can bind to functional groups of the biofilm constituents. This might lead to a decrease in the number of possible intermolecular interactions and, thus, reduced stability of the network. An impairment of the sediment stabilization due to enrichment of the AgNP in the biofilms might be detrimental to the whole ecosystem. In this work we studied the mechanical properties of an A. citratiphilum biofilm by means of rheology. The bacterium chosen is representative for a numerically dominant group of bacteria in different freshwater habitats. The biofilm was exposed to environmentally relevant concentrations of AgNP. In order to distinguish physical effects, resulting from the presence of the nanoparticles in the biofilms, from chemical effects, due to the activity of Ag+, we studied biofilms exposed to Ag+ as reference. We discuss our results in respect to their environmental implications.