Application of atomic force microscopy in the study of microbiologically influenced corrosion

This paper demonstrates the use of the atomic force microscope in high-resolution topographical imaging of bacteria, biofilm, and corroded steel surfaces, and in the quantification of localized corrosion. The nanometric physicochemical and mechanical properties of a single cell and bacterial biofilm surface are characterized by force mapping. The corrosion results in two different sulfate-reducing bacteria cultures showed that the patterns of pitting and the degree of corrosion of mild steel were related to the bacterial isolates. Results from measurement of the tip–biofilm and the tip–cell adhesion forces indicated that the extracellular polymeric substances were mainly distributed in the cell–substratum periphery or the cell–cell interface in the biofilm.