Chapter 9 : Biofilm Structure, Behavior, and Hydrodynamics

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This chapter covers the major discoveries associated with biofilm architecture and to discuss some instances where they in turn may be affected by environmental hydrodynamics. Understanding the significance of hydrodynamics in the biofilm life cycle is crucial if we consider the habitats in which the most abundant biofilms tend to accumulate. In summary there are a myriad of factors that influence biofilm development and structure. However, the interaction between hydrodynamics and each of these parameters is poorly characterized. The chapter discusses the influence of hydrodynamics and shear as the major factors that are involved in biofilm architecture, and it is important to keep in mind that all of the identified and yet-to-be-discovered factors are involved in a dynamic, interrelated manner and there is no single global regulating pathway so far known to control this process. The chapter also discusses the roles of hydrodynamics and shear in biofilm structural maturation as well as how they may affect the major factors that are involved in the process. In vitro studies performed in the laboratory and the observations of biofilms growing in the natural environment demonstrate the importance of hydrodynamics and shear in biofilm structural development.

Citation: Purevdorj-Gage, Stoodley P. 2004. Biofilm Structure, Behavior, and Hydrodynamics, p 160-173. In Ghannoum M, O'Toole G (ed), Microbial Biofilms. ASM Press, Washington, DC. doi: 10.1128/9781555817718.ch9
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Image of FIGURE 1

Structural phenotypes of both natural and laboratory biofilms are strikingly similar. A microbial biofilm growing in a hot spring in Biscuit geyser basin, Yellowstone National Park, forming ripple structures (A) was similar to the ones formed by mixed-species biofilms in the laboratory (B). A microbial biofilm with streamers in Canary Spring, Yellowstone National Park (C), was similar to streamers formed by a laboratory-grown biofilm (D). The direction of fluid flow in all panels was left to right. Bars, ∼20 cm (A and C) and 200 µm (B and D).

Citation: Purevdorj-Gage, Stoodley P. 2004. Biofilm Structure, Behavior, and Hydrodynamics, p 160-173. In Ghannoum M, O'Toole G (ed), Microbial Biofilms. ASM Press, Washington, DC. doi: 10.1128/9781555817718.ch9
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Image of FIGURE 2

Dynamic behavior and associated structural phenotypes of bacterial biofilms in flowing fluids. The various dynamic processes are discussed in the text. Schematic by P. Dirckx, Center for Biofilm Engineering, Montana State University, 2003.

Citation: Purevdorj-Gage, Stoodley P. 2004. Biofilm Structure, Behavior, and Hydrodynamics, p 160-173. In Ghannoum M, O'Toole G (ed), Microbial Biofilms. ASM Press, Washington, DC. doi: 10.1128/9781555817718.ch9
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Image of FIGURE 3

A structurally specialized biofilm cluster. The cluster is composed of an outer layer of nonmotile cells that form a “wall” (indicated by the white arrows). In the interior of the cluster cells swim about rapidly before flowing out, leaving the cluster empty. The flow direction is indicated by the black arrow. Bar, 20 µm.

Citation: Purevdorj-Gage, Stoodley P. 2004. Biofilm Structure, Behavior, and Hydrodynamics, p 160-173. In Ghannoum M, O'Toole G (ed), Microbial Biofilms. ASM Press, Washington, DC. doi: 10.1128/9781555817718.ch9
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