Post by toni on Dec 10, 2012 10:10:17 GMT -5
How bacteria regulate, assemble, and rotate flagella to swim in liquid
media is reasonably well understood.
Much less is known, however, about how some bacteria also use flagella
to move over the tops of solid surfaces in a form of movement called swarming.
As the focus of bacteriology changes from planktonic to surface environments,
interest in swarming motility is on the rise.
Bacteria have traditionally been viewed as unicellular organisms that grow as
dispersed individuals in a planktonic environment. Recently, this view has begun
to change with increasing awareness of the role of biofilms in which sessile bacteria
secrete an extracellular matrix and aggregate as multicellular groups.
Surface-associated bacteria have another option besides sessile aggregation;
sometimes the bacteria become highly motile and migrate over the substrate,
a process known as swarming.
Swarming motility is operationally defined as a rapid multicellular bacterial surface
movement powered by rotating flagella2 (Figure 1). Although simple, accurate, and
mechanistically meaningful, the definition does not do justice to the wide array of
phenotypes associated with swarming motility, nor does it emphasize all that remains
unknown about this behavior.
Furthermore, despite the simplicity of the definition, it is important to acknowledge
the common field-specific misnomers and distinguish swarming from behaviors such
as swimming, twitching, gliding, and sliding that can occur within, or on top of, solid surfaces.
www.ncbi.nlm.nih.gov/pmc/articles/PMC3135019/
media is reasonably well understood.
Much less is known, however, about how some bacteria also use flagella
to move over the tops of solid surfaces in a form of movement called swarming.
As the focus of bacteriology changes from planktonic to surface environments,
interest in swarming motility is on the rise.
Bacteria have traditionally been viewed as unicellular organisms that grow as
dispersed individuals in a planktonic environment. Recently, this view has begun
to change with increasing awareness of the role of biofilms in which sessile bacteria
secrete an extracellular matrix and aggregate as multicellular groups.
Surface-associated bacteria have another option besides sessile aggregation;
sometimes the bacteria become highly motile and migrate over the substrate,
a process known as swarming.
Swarming motility is operationally defined as a rapid multicellular bacterial surface
movement powered by rotating flagella2 (Figure 1). Although simple, accurate, and
mechanistically meaningful, the definition does not do justice to the wide array of
phenotypes associated with swarming motility, nor does it emphasize all that remains
unknown about this behavior.
Furthermore, despite the simplicity of the definition, it is important to acknowledge
the common field-specific misnomers and distinguish swarming from behaviors such
as swimming, twitching, gliding, and sliding that can occur within, or on top of, solid surfaces.
www.ncbi.nlm.nih.gov/pmc/articles/PMC3135019/