Bacterial gliding
Encyclopedia
Bacterial gliding is a process whereby a bacterium can move under its own power. This process does not involve the use of flagella, which is a more common means of motility
in bacteria. For many bacteria, the mechanism of gliding is unknown or only partially known, and it seems likely that in fact different bacteria use distinct mechanisms to achieve what is currently referred to as gliding. Gliding is prominent in cyanobacteria, myxobacteria
and the cytophaga-flavobacteria.
The only understood mechanism involves using type IV pili in such bacteria as Pseudomonas aeruginosa
and Myxococcus xanthus
. In addition, for Myxococcus xanthus A-motility (one of the two motility mechanisms this bacterium has) two other mechanisms have been proposed, one involving ejection of a polysaccharide
slime from nozzles at either end of the body and the other using "focal adhesion
complexes" distributed along the cell body.
Motility
Motility is a biological term which refers to the ability to move spontaneously and actively, consuming energy in the process. Most animals are motile but the term applies to single-celled and simple multicellular organisms, as well as to some mechanisms of fluid flow in multicellular organs, in...
in bacteria. For many bacteria, the mechanism of gliding is unknown or only partially known, and it seems likely that in fact different bacteria use distinct mechanisms to achieve what is currently referred to as gliding. Gliding is prominent in cyanobacteria, myxobacteria
Myxobacteria
The myxobacteria are a group of bacteria that predominantly live in the soil. The myxobacteria have very large genomes, relative to other bacteria, e.g. 9-10 million nucleotides. Sorangium cellulosum has the largest known bacterial genome, at 13.0 million nucleotides...
and the cytophaga-flavobacteria.
The only understood mechanism involves using type IV pili in such bacteria as Pseudomonas aeruginosa
Pseudomonas aeruginosa
Pseudomonas aeruginosa is a common bacterium that can cause disease in animals, including humans. It is found in soil, water, skin flora, and most man-made environments throughout the world. It thrives not only in normal atmospheres, but also in hypoxic atmospheres, and has, thus, colonized many...
and Myxococcus xanthus
Myxococcus xanthus
Myxococcus xanthus colonies exist as a self-organized, predatory, saprotrophic, single-species biofilm called a swarm. Myxococcus xanthus, which can be found almost ubiquitously in soil, are thin rod shaped, gram-negative cells that exhibit self-organizing behavior as a response to environmental...
. In addition, for Myxococcus xanthus A-motility (one of the two motility mechanisms this bacterium has) two other mechanisms have been proposed, one involving ejection of a polysaccharide
Polysaccharide
Polysaccharides are long carbohydrate molecules, of repeated monomer units joined together by glycosidic bonds. They range in structure from linear to highly branched. Polysaccharides are often quite heterogeneous, containing slight modifications of the repeating unit. Depending on the structure,...
slime from nozzles at either end of the body and the other using "focal adhesion
Focal adhesion
In cell biology, focal adhesions are specific types of large macromolecular assemblies through which both mechanical force and regulatory signals are transmitted. More precisely, they can be considered as sub-cellular macromolecules that mediate the regulatory effects In cell biology, focal...
complexes" distributed along the cell body.