Page 38 - MNU microbiology theoritical 2025

General Microbiology & Immunology (PM 401) Second level Semester 4 2024/2025

• The forespore, which is enclosed by two membranes,

becomes the core of the endospore.

• Peptidoglycan-containing material is laid down between

these two membranes, forming the core wall and the

cortex.

• Mother cells make proteins that form the spore coat.

• Further maturation of the endospore occurs with the

formation of an outermost exosporium.

• Mother cell is degraded, and the endospore released

Structure

The layers of the endospore shield it from damage.

1- Exosporium: The outermost layer

2- Spore coat: function as a sieve, excluding molecules such as lysozyme.

3- Cortex: maintain the core in a dehydrated state, protecting it from the effects of
heat

4- Core : it protects DNA from damage.

Contains dipicolinic acid, which combines with calcium ions, plays a role

in spore resistance

General Microbiology & Immunology (PM 401) theoretical handbook Page 27