We have observed
Bacillus subtilis micro-colony by using scanning electron microscope and optical microscope.
In the previous report, a cell on a agar plate grew drawing the curved string without cut off one string. Shapes of micro colony formed on agar plates were changed in response to agar concentration, nutrient concentration and other environments.
In this report, we took notice of relationships between agar concentration and micro colony morphology. A cell string had a small amount of curvature under low agar concentrations. Under high concentrations curvatures increase in size. Under all concentrations tested filament chains of cells were twisted, especially under medium concentrations double stranded helical structures were observed at many parts of the peripheral domain of the colony.
Furthermore, we discussed the ecological meanings of one string and twisted growth of this bacteria.
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