Atomic Force Microscopy Studies of Bacteria at an Interface Lin Duong and Elaine Ly

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Bdellovibrio bacteriovorus is a small flagellated bacterium that preys on Gram-negative bacteria.The life cycle of Bd ellovibrio is divided into a host-independent stage and a host-dependent stage. During predation, a Bdellovibrio cell first attaches to the outer cell wall of the host cell. Then, the Bdellovibrio enters the host's perisplasmic space where it utilizes nutrients to reproduce through division. Atomic Force Microscopy (AFM) has been used to characterize Bdellovibrios attack on its prey at a hydrated interface at high resolution. In preparation for AFM studies of Bdellovibrio , the AFM has been employed to study E. coli at a solid mica-air interface. Air AFM studies of E. coli on distilled water, MgCl2, and sucrose have been collected?each sample showing different features that we attribute to be a result to drying artifacts.The life cycles of Bdellovibrios that prey on E. coli and Aquaspirillum serpens have been imaged and studied on an air-hydrated solid surface interface without any chemical or physical modifications. Images collected showed multiple Bdellovibrio invasions of each host, differences in surface properties for various stages in the life cycle, and host-independent Bdellovibrios with flagella and a coating of slime. We also used the air-hydrated solid interface method to compare morphological differences between host-independent and wild-type host-dependent Bdellovibrios. The air-hydrated solid interface procedure has been shown to be a viable method to further study of bacterial processes, allowing us to delve deeper into bacterial communities like biofilms and bacterial surfaces characteristics using force measurements.


E. Spain, M. Nu?ez, & M. Martin




Support provided by:Howard Hughes Medical Institute and James Irvine Foundation

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