Atomic Force Microscopy Studies of Bacteria at the Solid-Liquid Interface.

Bdellovibrio is a small bacterium that preys on Gram-negative bacteria. The life of Bdellovibrio is divided into a host independent stage and a host dependent stage. During predation, Bdellovibrio first attaches to the outer cell wall of the host cell. Then, the Bdellovibrio enters the host\u27s perisplasmic space where it utilizes nutrients to reproduce through division. Atomic Force Microscopy (AFM) will be used to characterize Bdellovibrio\u27s attack of its prey under physiological conditions and at high magnification and resolution. In preparation for AFM studies of Bdellovibrio , AFM is employed to study Escherichia coli ( E. coli ) at the solid-liquid interface. Air AFM studies of E. coli in distilled water, MgCl2, and sucrose have been collected. Images of E. coli in distilled water showed lysed cells, while images in MgCl2 showed intact cells with white elevated areas. Images in sucrose showed indentions in the center of the cell, which indicates drying due to the buffer. Studies of E. coli will be conducted using TappingMode AFM in air and fluid under different media. Finally, images of E.coli will be measured using optical microscopy and transmission electron microscopy to provide a comprehensive investigation into preparation and medium issues regarding AFM imaging of bacterial structure and dynamics