Bacterial Endospores

1. BACTERIAL
ENDOSPORES
Dr. P. Saranraj

2. BACTERIAL ENDOSPORES
 Endospores are the resisting structures formed by
bacteria for survival during adverse environmental
condition.
 Endospores differ significantly from the vegetative
and normal functioning of cells.
 Endospores provide resistance against
 Heat
 Drying
 Low nutrient conditions
 Radiation
 Osmotic pressure
 Various chemical disinfectants

3. SPORE PROTEINS
 Dipicolinic acid
 Located in the core
 Calcium – Dipicolinic acid complexes reduces water
available and helps to dehydrate spores.
 Interculates into the DNA and stabilizes it to heat
denaturation.
 Small Acid Soluble Proteins (SASPs)
 Bind to the DNA in the core and protect it from damage.
 Function as a carbon and energy source when forming
vegetative cells to spore cells.

4. NOT ALL BACTERIAL SPECIES CAN FORM
SPORES
 A few genera of bacteria produce Endospore
such as Clostridium (Gangrene) and Bacillus
(Anthrax), both of them are Gram + rods
(Endospore production is associated with
Gram Positive bacteria)
 Since not all bacteria form Endospores, we
can use this as an identification factor.

5. THE SHAPE OF THE SPORE IS AN
IDENTIFYING CHARACTERISTIC
 Swelled vs. Not swelled
spore
Bacterial cell spore
Bacterial cell

6. LOCATION OF THE SPORES
 Central, Sub-Terminal, and Terminal spores

8. SOME SPORE FORMING BACTERIA ARE
CAPABLE OF CAUSING DISEASE
 Clostridium botulinum – Botulism
 Clostridium perfingens – Gas gangrene
 Clostridium tetani – Tetanus
 Bacillus anthrasis – Woolsorter’s Disease and
Wound infections
 The Schaeffer-Fulton Stain Procedure is used to
differentiate between endospores and vegetative
cells

9. ENDOSPORE STAINING