HR: 1340h
AN: B33A-0865    [Abstracts]
TI: Clay-Bacteria Systems and Biofilm Production
AU: * steiner, J
EM: steiner@sci.ccny.cuny.edu
AF: Department of Earth and Atmospheric Sciences, City College of New York, CUNY 160 Convent Avenue, New York, NY 10031, United States
AU: * steiner, J
EM: steiner@sci.ccny.cuny.edu
AF: PhD Program Earth and Environmental Sciences, City University of New York 365 5th Avenue, New York, NY 10016, United States
AU: Alimova, A
EM: aalimova@sci.ccny.cuny.edu
AF: Institute for Ultrafast Spectroscopy and Lasers, City College of New York, CUNY 160 Convent Avenue, New York, NY 10031, United States
AU: Katz, A
EM: akatz@ccny.cuny.edu
AF: Institute for Ultrafast Spectroscopy and Lasers, City College of New York, CUNY 160 Convent Avenue, New York, NY 10031, United States
AU: Steiner, N
EM: nick.steiner@gmail.com
AF: PhD Program Earth and Environmental Sciences, City University of New York 365 5th Avenue, New York, NY 10016, United States
AU: Rudolph, E
EM: lizrud@sci.ccny.cuny.edu
AF: Department of Earth and Atmospheric Sciences, City College of New York, CUNY 160 Convent Avenue, New York, NY 10031, United States
AU: Gottlieb, P
EM: pgottl@med.cuny.edu
AF: Sophie Davis School of Biomedical Education, City College of New York, CUNY 160 Convent Avenue, New York, NY 10031, United States
AB: Soil clots and the aerosol transport of bacteria and spores are promoted by the formation of biofilms (bacteria cells in an extracellular polymeric matrix). Biofilms protect microorganisms by promoting adhesion to both organic and inorganic surfaces. Time series experiments on bacteria-clay suspensions demonstrate that biofilm growth is catalyzed by the presence of hectorite in minimal growth media for the studied species: Gram negatives (Pseudomonas syringae and Escherichia coli,) and Gram positives (Staphylococcus aureus and Bacillus subtilis). Soil organisms (P. syringae, B. subtilis) and organisms found in the human population (E. coli, S. aureus) are both used to demonstrate the general applicability of clay involvement. Fluorescent images of the biofilms are acquired by staining with propidium iodide, a component of the BacLightTM Live/Dead bacterial viability staining kit (Molecular Probes, Eugene, OR). The evolving polysaccharide-rich biofilm reacts with the clay interlayer site causing a complex substitution of the two-water hectorite interlayer with polysaccharide. The result is often a three-peak composite of the (001) x-ray diffraction maxima resulting from polysaccharide-expanded clays and an organic-driven contraction of a subset of the clays in the reaction medium. X-ray diffractograms reveal that the expanded set creates a broad maximum with clay subsets at 1.84 nm and 1.41 nm interlayer spacings as approximated by a least squares double Lorentzian fit, and a smaller shoulder at larger 2q, deriving from a contraction of the interlayer spacing. Washing with chlorox removes organic material from the contracted clay and creates a 1-water hectorite single peak in place of the double peak. The clay response can be used as an indirect indicator of biofilm in an environmental system.
DE: 0418 Bioremediation
DE: 0419 Biomineralization
DE: 0448 Geomicrobiology
DE: 0463 Microbe/mineral interactions
DE: 1865 Soils (0486)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting