Abstract
We have been investigating how to use microorganisms for bio-micromachines. We succeeded to control the motion of the protists, using their galvano-taxis and phototaxis. In this study, we investigated how to control Bacillus subtilis using their chemotaxis. The difficult point to make a motion control system using chemotaxis is that once we sprayed the chemical substances for control, how to erase this effect in the next control. We thought the neutralization is suitable if we use acid/alkaline as a spraying substances. First, we investigated the basic reaction of Bacillus subtilis to the acid and the alkaline solution. Generally, Bacillus subtilis is thought to prefer neutral (pH7) circumstance. Our results, however, showed that Bacillus gathered to the acid. Next, we made a chemical substance spraying system by modifying the inkjet printer. By using this system, we can make/disappear the character by the bacteria group.
