Control of flagellar motor using a real-time local environment chemical stimulation system

Single cell analysis has attracted much attention to reveal the localized biological information in detail. Local environmental control technique is developed to analyze the localized detail properties of single cells. In this paper, we propose the local environmental chemical stimulation system with micro dual pipettes to stimuli the local reagent concentration dynamically and automatically. Local environmental chemical stimulation by dual pipettes is applied to the rotational speed control of bacterial flagellar motor, which is a rotary molecular machine. Here, we show quick response and rotational speed control of Na-driven flagellar motor in both accelerating and relaxing directions was demonstrated by automatic switching the local spout between Na-containing and Na-free solutions with dual pipettes. It was shown that the rotational speed could be maintained by automatic controlling the spouting velocity of Na-containing and Na-free solution with multiplying the applied DC voltage. Furthermore, it was confirmed that by applying the P-control, rotational speed of flagellar motor could be controlled more stably.