Effects of high hydrostatic pressure on bacterial cytoskeleton FtsZ polymers in vivo and in vitro

Some rod-shaped bacteria, including Escherichia coli, exhibit cell filamentation without septum formation under high-hydrostatic-pressure conditions, indicating that the cell-division process is affected by hydrostatic pressure. The effects of elevated pressure on FtsZ-ring formation in E coli cells were examined using indirect immunofluorescence microscopy. Elevated pressure of 40 MPa completely inhibited colony formation of E coli cells under the cultivation conditions used, and the cells exhibited obviously filamentous shapes. In the elongated cells, normal cell-division processes appeared to be inhibited, because no FtsZ rings were observed by indirect immunofluorescent staining. In addition, it was observed that hydrostatic pressure dissociated the E coli FtsZ polymers in vitro. These results suggest that high hydrostatic pressure directly affects cell survival and morphology through the dissociation of the cytoskeletal frameworks.