+
Related Flashcards
Related Topics
Cards In This Set
| Front | Back |
|
A number of gram positive bacteria can form a special resistant , dormant structure called
|
Endospores
|
|
Endospores develop within vegetative bacterial cells of several genera
|
Bacillus and clostridium(rods), sporosarcina (cocci) ,and others
|
|
These structures are extraordinarily resistant to environmental stresses such as
|
Heat UV radiation gamma radiation chemical disinfectants and desiccation
|
|
In fact some endospores have remained viable for around
|
100,000 years
|
|
And actinomycete spores have been recovered alive after burial in the mud for
|
7,500 years
|
|
Because of their resistance and the fact that several species of endospores forming bacteria
|
Are dangerous pathogens
|
|
Endospores are of great practical importance in
|
Food industrial and medical microbiology
|
|
This is because it is essential to be able to
|
Sterilise solutions and solid objects
|
|
Endospores often survive
|
Boiling for an hour or more
|
|
Therefore autoclaves must be used ton
|
Sterilise many materials
|
|
Endospores are also of
|
Considerable theoretical interest
|
|
In the environment, endospores aid in survival
|
When moisture or nutrients are scarce
|
|
Endospores can be examined with both
|
Light and electron microscope
|
|
Because spores are impermeable to most stains
|
They are often seen as colourless area in bacteria treated with methylene blue and other simple stains
|
|
Special spore stains are used
|
To make them clearly visible
|
