Inhibition and enhancement of microbial surface colonization: the role of silicate composition

Chemical Geology
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Abstract

Classical treatment of cell attachment by models of filtration or coulombic attraction assumes that attachment of cells to mineral surfaces would be controlled by factors such as response to predation, collision efficiency, or coulombic attraction between the charged groups at the mineral and cell surfaces. In the study reported here, the passive model of attachment was investigated using a native microbial consortium and a variety of Al- and Fe-bearing silicates and oxides to determine if other controls, such as mineral composition, also influence the interaction between cells and surfaces. Results from in situ colonization studies in an anaerobic groundwater at pH 6.8 combined with most probable number analyses (MPN) of surface-adherent cells demonstrate that electrostatic effects dominate microbial colonization on positively charged oxide surfaces regardless of mineral composition. In contrast, on negatively charged silicate minerals and glasses, the solid phase composition is a factor in determining the extent of microbial colonization, as well as the diversity of the attached community. In particular, silicates containing more than 1.2% Al exhibit less biomass than Al-poor silicates and MPN suggests a shift in community diversity, possibly indicating Al toxicity on these surfaces. When Fe is present in the silicate, however, this trend is reversed and abundant colonization of the surface is observed. Here, microorganisms preferentially colonize those silicate surfaces that offer beneficial nutrients and avoid those that contain potentially toxic elements.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Inhibition and enhancement of microbial surface colonization: the role of silicate composition
Series title Chemical Geology
DOI 10.1016/j.chemgeo.2004.08.021
Volume 212
Issue 3-4
Year Published 2004
Language English
Publisher Elsevier
Contributing office(s) Toxic Substances Hydrology Program
Description 15 p.
First page 313
Last page 327