Rapid rotation of flagellar bundles in swimming bacteria

  title={Rapid rotation of flagellar bundles in swimming bacteria},
  author={Graeme Lowe and Markus Meister and Howard C. Berg},
A bacterial flagellum is driven by a reversible rotary motor1–3. The power input is determined by protonmotive force and proton flux, the power output by torque and speed: interrelationships between these parameters provide important clues to motor mechanisms. Here we describe the relationship between torque and speed at constant protonmotive force. The measurements are analogous to those that could be made by plugging an electric motor into a constant-voltage outlet, varying the external load… 
Torque generated by the flagellar motor of Escherichia coli while driven backward.
Energy transduction in the bacterial flagellar motor. Effects of load and pH.
On Torque and Tumbling in Swimming Escherichia coli
Bacteria swim by rotating long thin helical filaments, each driven at its base by a reversible rotary motor, and motor reversals were necessary, although not always sufficient, to cause changes in filament chirality.
Torque-speed relationship of the Na+-driven flagellar motor of Vibrio alginolyticus.
The bacterial flagellar motor.


Energetics of flagellar rotation in bacteria.
Coordination of flagella on filamentous cells of Escherichia coli
Although the directions of rotation of flagellar motors are not controlled by a common intracellular signal, their biases are, and this signal appears to have a limited range.
Bacterial motility and the bacterial flagellar motor.
Bacteria are exposed to a wide range of environments, some hostile, some benign, and their ability to modify their environment is quite limited, so the dominant strategy that has evolved, therefore, is selective motion toward environments that enhance the prospects for survival.
Chemotactic signaling in filamentous cells of Escherichia coli
The range of the signal was found to be substantially longer in a cheZ mutant, suggesting that the product of the cheZ gene contributes to this inactivation, and shows that there is an internal signal, but its range is short, only a few micrometers.
Movement of microorganisms in viscous environments
Data show that solutions of methylcellulose are gel-like even when quite dilute, when the bulk viscosity is as small as 2 cP, and that solutions containing highly branched polymers, for example, Ficoll, are much more homogeneous.
Effect of temperature on motility and chemotaxis of Escherichia coli
The swimming velocity of Escherichia coli at various constant temperatures was found to increase with increasing temperature. The frequency of tumbling had a peak at 34 degrees C and was very low
Chemotaxis in bacteria.
  • H. Berg
  • Biology
    Annual review of biophysics and bioengineering
  • 1975
Bacteria swim by rotating their flagella and alter course by abruptly changing the direction of this rotation, which changes the concentration of the attractant or repellent with time.