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Monitoring Spatial Segregation in Surface Colonizing Microbial Populations
Published on: October 29, 2016
Chiral self-propulsion of growing bacterial macrofibers on a solid surface
N H Mendelson1, J E Sarlls, C W Wolgemuth
1Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721, USA.
Physical Review Letters
|October 4, 2000
Summary
Bacterial macrofiber growth drives self-propulsion through supercoiling motions. This study quantoys the elastic properties of the bacterial cell wall, revealing its role in generating movement.
Area of Science:
- Microbiology
- Biophysics
- Cellular mechanics
Background:
- Bacillus subtilis forms multicellular filamentous structures called macrofibers through cell division without separation.
- Supercoiling motions during macrofiber growth are observed to drive movement on surfaces.
Purpose of the Study:
- To investigate the mechanisms behind the self-propulsion of bacterial macrofibers.
- To quantify the forces and torques generated by macrofiber growth.
- To measure the elastic properties of the bacterial cell wall.
Main Methods:
- Observation of supercoiling motions during bacterial macrofiber growth.
- Analysis of forces and torques generated by cell growth against friction.
- Optical trapping studies to measure the Young's modulus of the bacterial cell wall.
Main Results:
- Supercoiling motions enable rolling, pivoting, and walking of bacterial macrofibers.
- Cell growth forces, when impeded by friction, lead to self-propulsion.
- The elastic engine generates torques of microdyn cm and power of femtowatts.
- Young's modulus of the bacterial cell wall was directly measured at approximately 0.05 GPa.
Conclusions:
- Bacterial macrofiber self-propulsion is a result of supercoiling-driven mechanics.
- The bacterial cell wall acts as the 'working fluid' of an elastic engine generating motion.
- Direct measurement of cell wall elasticity provides insight into the physical basis of bacterial motility.
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