[Dependence of monotrachial bacteria chemotaxis on the direction of flagella rotation]

Monotrichous bacteria V. harveyi periodically reverse their direction when moving in a liquid environment. It is reported that in a uniform surrounding the motility pattern is composed of a repeat of two sequential runs: a short and a long one separated by a reversal. The main duration of the short run was 0.4 sec and of the long one - 1.3 sec. Upon the addition of attractants or repellents the long runs became prolonged or shortened correspondingly. The duration of the short runs was independent of attractant or repellent stimuli. It is concluded that the flagellum is unresponsive to the taxis signal when rotating clockwise, which corresponds to the short run.