On the Aperiodic Locomotor Behavior of Halobacterium salinarium Under Periodic Light Stimuli

Two long time series of swimming intervals of a bacterium inverting its motion under periodic light pulses are analysed. The associated next-period plots reveal, through their filiform structure, that the underlying dynamics are low-dimensional. Using recently described properties of such dynamics, a simple second-order black-box model for the swimming intervals is derived and validated. The model reinforces the conjecture that this bacterium is endowed with an oscillator controlling the switching of the flagellar motor.