This document summarizes the process of sporulation in microorganisms. It describes that spores form as a protective structure during unfavorable conditions and can survive without nutrients. There are two main types of spores - endospores, which form inside the cell, and exospores, which form on the surface. Spores have protective coats, cortex, germ cell wall, and a central core containing DNA. Sporulation is the process where a single cell forms an endospore or exospore, which can later germinate into a new cell under favorable conditions. Key factors like sigma factors regulate genes involved in sporulation and returning to the vegetative state.

1. MICROBIOLOGY
SPORULATION
By keerthana.c

2. What are spores?
• It is a unicellular structure.
• Spores form a life cycle in many plants, algae,
bacteria, fungi and protozoa.
• Spores are formed during unfavorable
conditions.
• They can survive without nutrients.
• it forms highly resistant structure.

3. Types of spores
• There are two types of spore
1) endospores.
2) exospores.
• Endospores- are formed within the vegetative
cell. (inside the cell).
• Exospores- are formed in either one of the ends
of the vegetative cell. (on the surface of the cell).

4. Structure of spore

5. structure
• The outer and inner coat made up of protein
and they provides chemical and enzymatic
resistance to the spores.
• Cortex region lies between the region of
outer and inner coat and it is made up of
peptidoglycon.
• Cortex helps in dehydration process during
sporulation process and thus providing high
temperature resistance.

6. • Germ cell wall protects from potentially
damaging chemicals and it protects the central
core.
• The central core portion consists of DNA, small
amounts of RNA, ribosomes, enzymes and
nearly 40% of dipiclonic acid. (DPA)
• This DPA helps in preventing the damage
against DNA by chemicals present in the
environment.

7. sporulation
• The process of production of spores is called
sporulation or sporogenesis.
• The one vegetative cell forms a single spore,
which, after germination, develops into a new
cell.
• It takes 8hrs-19 hrs to compelete.

8. Endospores formation

9. Exospores formation

10. Exospores development
• In exospores formation spores developed
outside the body.
• They developed attached with a outer surface of
the cell wall.
• During the unfavorable conditions
Primarily, the mother cell and the daughter cells
are divided by means of the septum and later it
forms a bud like structure at the outer covering.

11. • The cytoplasmic division results in the bud and
it is covered by a double layered membrane.
• Later it is followed by outer and inner coat
development and thus resulting exospores
• During favorable conditions the bud get
detached from the body and it is followed by
germination.

12. germination
• Sporulation is followed by germination.
• An endospores and exospores returns to its
vegetative state by a process called
germination.
• Germination is triggered by physical or
chemical damage to the endospores coat.

13. • When the environmental conditions become
favor of the bacteria, the spores are reactivated
and thus giving rise to a new bacterial cell.
• This is not a process of reproduction
• Vegetative cell produces a single spore
which in turn forms a new bacterial cell.

14. Sigma factor
• A sigma factor (σ factor) is a protein
needed only for initiation of RNA synthesis.
• It is a bacterial transcription initiation factor
that enables specific binding of RNA
polymerase to gene promoters.

15. • The specific sigma factor used to initiate
transcription of a given gene will vary,
depending on the gene and on the
environmental signals needed to initiate
transcription of that gene.
• Depending upon the environment it also
initiates sporulation process.

16. Thank you