Despite the fact that extensive investigations have been undertaken on spore germination,
coat structure, and clostridial cell growth from spores ,
there is a relative lack of information regarding the cell's exit from its protective coats.
The purpose of the present study was to build on previous observations in C. sporogenes,
Clostridium pasteurianum
and B. anthracis that the spore exosporium may have a hole or “bottle cap” at its pole.
In particular we show that the rupture of the C. sporogenes spore coat occurs adjacent to the pre-formed aperture
in the exosporium, and that the germinated cell emerges through aligned openings in the spore coat and the exosporium.