Fig. 2

Sporulation of B. cereus 0–9 and its ΔspoVG mutant. Wild B. cereus 0–9 and its ΔspoVG mutant were cultured in MG medium at 30 °C and 220 rpm, and stained with two fluorescent dyes. And then, observed under a fluorescence microscope. For the membrane, only the red fluorescence signal of FM4–64 was collected, that is, the cell membrane and spore-coat were stained red; For the cell nucleus, only the blue signal of DAPI is collected, that is, the nuclear DNA is stained blue; And the merge images of the membrane and nuclear DNA showed the overall perspective. The sporulation of ΔspoVG mutant doesn’t have the characteristic structure of stage V, it stoped in the stage III-V