The behavioural response of to temporal changes in the concentration of chemoeffectors, and to stimuli affecting electron transport, was analysed using tethered cells. Populations of photosynthetically grown tethered cells of showed a transient response, a stop followed by adaptation, to a stepwise reduction in the concentration of chemoattractants (such as organic acids or sugars) and terminal electron acceptors. A step-down response was also measured in free swimming cells to a reduction in light intensity. As this response appears to apply to all effectors this suggests that there is a sensory pathway in anaerobically grown which responds primarily to a reduction in a stimulus. therefore responds when moving down a concentration gradient. This is the inverse of the classical model of bacterial sensory behaviour in which bacteria respond primarily when there is an increase in an attractant concentration, i.e. when moving up a gradient. does show a chemokinetic response to an increase in concentration of a limited number of compounds but this response is sustained and accompanied by an increase in the rate of flagellar rotation and therefore not simply equivalent to the transient increase in smooth swimming measured in on addition of an attractant.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error