Use of a microchamber for analysis of thermal variation of the gliding phenomenon of single Navicula pavillardii cells.

In this study, we used a microchamber to observe and analyze the gliding phenomenon of Navicula pavillardii diatom cells at different temperatures. The temperature of the culture medium was varied from 17.0 to 30.0 °C to examine the effect of temperature on diatom movement. Movement of each cell at different temperatures was monitored by use of an inverted optical microscope and continuously recorded as video data, from which the velocities of each cell were calculated, by using dedicated software to perform two-dimensional trajectory analysis. The velocities of the same cell at different temperatures were thereby successfully compared. The results showed that the change in cell velocity was insignificant when the temperature was increased from 17.0 to 25.0 °C. When the temperature was increased from 17.0 to 27.5 °C, non-uniformly disrupted cell movement was observed. When the temperature was further increased to 30.0 °C, cell movement was clearly inhibited. By use of single-cell analysis, the effects of the temperature increases on diatom movement were successfully evaluated. Finally, we characterized the experimental data by performing t tests to evaluate the effects of variations of the movement of individual cells on the data analysis.