Bacterial sheet-powered rotation of a micro-object

Recently, there have been numerous reports of the use of microbes as bio-actuators. In particular, bacteria are one of the promising candidates for bioactuator development, because of which they have garnered a lot of interest lately. In this paper, we developed a new system for the transport of a micro-object by using surface swarming Vibrio alginolyticus, a marine bacterium, and achieved high-speed movement of the micro-object. First, we confirmed if YM19 and YM19ΔcheY, two genetic variant strains of V. alginolyticus that are appropriate for surface swarming, were able to transport microbeads. We found that the transport speed of YM19ΔcheY was higher than that of YM19, and this confirmed high validity of genetic modification. We further tried to control the movement by constructing a microwall and succeeded in causing the rotational transport of the micro-object. Finally, we demonstrated microgear rotation with a rotational speed that was about 7 rpm, thus confirming the effectiveness of our proposed method.