This multicellular behavior has been mostly observed in controlled laboratory conditions and relies on two critical elements: 1) the nutrient composition and 2) viscosity of culture medium (i.e. % agar).[5] One particular feature of this type of motility is the formation of dendritic fractal-like patterns formed by migrating swarms moving away from an initial location. Although the majority of species can produce tendrils when swarming, some species like Proteus mirabilis do form concentric circles motif instead of dendritic patterns.[19]
Biosurfactant, quorum sensing and swarming
In some species, swarming motility requires the self-production of
biosurfactant to occur.[5][20] Biosurfactant synthesis is usually under the control of an intercellular communication system called
quorum sensing. Biosurfactant molecules are thought to act by lowering surface tension, thus permitting bacteria to move across a surface.
Cellular differentiation
Swarming bacteria undergo morphological differentiation that distinguish them from their planktonic state. Cells localized at migration front are typically hyperelongated, hyperflagellated and grouped in multicellular raft structures.[11][12][21][22]
Ecological significance
The fundamental role of swarming motility remains unknown. However, it has been observed that active swarming bacteria of Salmonella typhimurium shows an elevated resistance to certain antibiotics compared to undifferentiated cells.[23]
^McCarter, Linda L. (2004). "Dual Flagellar Systems Enable Motility under Different Circumstances". Journal of Molecular Microbiology and Biotechnology. 7 (1–2): 18–29.
doi:
10.1159/000077866.
PMID15170400.
S2CID21963003.
This multicellular behavior has been mostly observed in controlled laboratory conditions and relies on two critical elements: 1) the nutrient composition and 2) viscosity of culture medium (i.e. % agar).[5] One particular feature of this type of motility is the formation of dendritic fractal-like patterns formed by migrating swarms moving away from an initial location. Although the majority of species can produce tendrils when swarming, some species like Proteus mirabilis do form concentric circles motif instead of dendritic patterns.[19]
Biosurfactant, quorum sensing and swarming
In some species, swarming motility requires the self-production of
biosurfactant to occur.[5][20] Biosurfactant synthesis is usually under the control of an intercellular communication system called
quorum sensing. Biosurfactant molecules are thought to act by lowering surface tension, thus permitting bacteria to move across a surface.
Cellular differentiation
Swarming bacteria undergo morphological differentiation that distinguish them from their planktonic state. Cells localized at migration front are typically hyperelongated, hyperflagellated and grouped in multicellular raft structures.[11][12][21][22]
Ecological significance
The fundamental role of swarming motility remains unknown. However, it has been observed that active swarming bacteria of Salmonella typhimurium shows an elevated resistance to certain antibiotics compared to undifferentiated cells.[23]
^McCarter, Linda L. (2004). "Dual Flagellar Systems Enable Motility under Different Circumstances". Journal of Molecular Microbiology and Biotechnology. 7 (1–2): 18–29.
doi:
10.1159/000077866.
PMID15170400.
S2CID21963003.