title: In Situ Analysis of a Silver Nanoparticle-Precipitating Shewanella Biofilm by Surface Enhanced Confocal Raman Microscopy.
abstract: Shewanella oneidensis MR-1 is an electroactive bacterium, capable of reducing extracellular insoluble electron acceptors, making it important for both nutrient cycling in nature and microbial electrochemical technologies, such as microbial fuel cells and microbial electrosynthesis. When allowed to anaerobically colonize an Ag/AgCl solid interface, S. oneidensis has precipitated silver nanoparticles (AgNp), thus providing the means for a surface enhanced confocal Raman microscopy (SECRaM) investigation of its biofilm. The result is the in-situ chemical mapping of the biofilm as it developed over time, where the distribution of cytochromes, reduced and oxidized flavins, polysaccharides and phosphate in the undisturbed biofilm is monitored. Utilizing AgNp bio-produced by the bacteria colonizing the Ag/AgCl interface, we could perform SECRaM while avoiding the use of a patterned or roughened support or the introduction of noble metal salts and reducing agents. This new method will allow a spatially and temporally resolved chemical investigation not only of Shewanella biofilms at an insoluble electron acceptor, but also of other noble metal nanoparticle-precipitating bacteria in laboratory cultures or in complex microbial communities in their natural habitats.
authors.affiliation: Department of Dynamics of Complex Fluids, Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany.|Department of Environmental Microbiology, Helmholtz Centre for Environmental Research, Leipzig, Germany.|Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research, Leipzig, Germany.
authors.forename: Gal
authors.initials: G
authors.lastname: Schkolnik
authors.affiliation: Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research, Leipzig, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Schmidt
authors.affiliation: Department of Dynamics of Complex Fluids, Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany.
authors.forename: Marco G
authors.initials: MG
authors.lastname: Mazza
authors.affiliation: Department of Environmental Microbiology, Helmholtz Centre for Environmental Research, Leipzig, Germany.
authors.forename: Falk
authors.initials: F
authors.lastname: Harnisch
authors.affiliation: Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research, Leipzig, Germany.
authors.forename: Niculina
authors.initials: N
authors.lastname: Musat
mesh_terms: D018441:Biofilms / Q000254:growth & development; D011232:Chemical Precipitation; D003580:Cytochromes / Q000378:metabolism; D005415:Flavins / Q000378:metabolism; D053768:Metal Nanoparticles; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D010084:Oxidation-Reduction; D010710:Phosphates / Q000378:metabolism; D011135:Polysaccharides, Bacterial / Q000378:metabolism; D020592:Shewanella / Q000502:physiology* / Q000648:ultrastructure; D012834:Silver; D013059:Spectrum Analysis, Raman; D013499:Surface Properties
chemical_list: D003580:Cytochromes; D005415:Flavins; D010710:Phosphates; D011135:Polysaccharides, Bacterial; D012834:Silver