Osmotic Pressure in a Bacterial Swarm

DSpace/Manakin Repository

Osmotic Pressure in a Bacterial Swarm

Citable link to this page


Title: Osmotic Pressure in a Bacterial Swarm
Author: Ping, Liyan; Wu, Yilin; Hosu, Basarab Gabriel; Tang, Jay Xin; Berg, Howard Curtis

Note: Order does not necessarily reflect citation order of authors.

Citation: Ping, Liyan, Yilin Wu, Basarab G. Hosu, Jay X. Tang, and Howard C. Berg. 2014. “Osmotic Pressure in a Bacterial Swarm.” Biophysical Journal 107, no. 4: 871–878. doi:10.1016/j.bpj.2014.05.052.
Full Text & Related Files:
Abstract: Using Escherichia coli as a model organism, we studied how water is recruited by a bacterial swarm. A previous analysis of trajectories of small air bubbles revealed a stream of fluid flowing in a clockwise direction ahead of the swarm. A companion study suggested that water moves out of the agar into the swarm in a narrow region centered ~30 mm from the leading edge of the swarm and then back into the agar (at a smaller rate) in a region centered ~120 mm back from the leading edge. Presumably, these flows are driven by changes in osmolarity. Here, we utilized green/red fluorescent liposomes as reporters of osmolarity to verify this hypothesis. The stream of fluid that flows in front of the swarm contains osmolytes. Two distinct regions are observed inside the swarm near its leading edge: an outer high-osmolarity band (~30 mOsm higher than the agar baseline) and an inner low-osmolarity band (isotonic or slightly hypotonic to the agar baseline). This profile supports the fluid-flow model derived from the drift of air bubbles and provides new (to our knowledge) insights into water maintenance in bacterial swarms. High osmotic pressure at the leading edge of the swarm extracts water from the underlying agar and promotes motility. The osmolyte is of high molecular weight and probably is lipopolysaccharide.
Published Version: doi:10.1016/j.bpj.2014.05.052
Terms of Use: This article is made available under the terms and conditions applicable to Open Access Policy Articles, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#OAP
Citable link to this page: http://nrs.harvard.edu/urn-3:HUL.InstRepos:34310043
Downloads of this work:

Show full Dublin Core record

This item appears in the following Collection(s)


Search DASH

Advanced Search