Ethological dynamics in diorama environments

Many bacterial species move toward favorable habitats. The flagellum is one of the most important machines required for the motility in solution and is conserved across a wide range of bacteria. The motility machinery is thought to function efficiently with a similar mechanism in a variety of environmental conditions, as many cells with similar machineries have been isolated from harsh environments. To understand the common mechanism and its diversity, microscopic examination of bacterial movements is a crucial step. In previous studies, we developed a high-pressure microscope that is optimized both for the best image formation and for the stability to hydrostatic pressure up to 150 MPa. This withstanding pressure is higher than the hydrostatic pressure in the deepest part of the Mariana Trench, the highest found outside the crust of the earth. The developed system allowed us to monitor the swimming motility of bacterial cells at various pressure conditions. In this study, we will construct the environment of hydrothermal vents in the deep sea under a microscope, and then study the swimming motility of extremophiles.