3-10 Endospore Stain

3 possible locations for endospores in cell

1. central aka. middle of the cell 2. terminal aka end 3. sub-terminal aka. between middle and very end of cell

How old do the cultures of endospore-forming bacteria need to be before the bacteria start producing endospores?

5-7 days old

How long can endospores remain viable (capable of germinating into vegetative cells)?

50 yrs

What is difference between an endospore and a vegetative cell?

A vegetative cell is a living, active cell that can reproduce. An endospore is a spore in a capsule that is resistant to harsh conditions. Although it is living or active, it cannot reproduce nor produce ATP (metabolize).

Bacillus anthracis

Aerobic endospore-forming bacteria; causes anthrax (3 forms: inhalation/pulmonary, cutaneous aka skin, gastric intestinal)

Bacillus cereus

Aerobic endospore-forming bacteria; causes food poisoning within 2 to 6 hours of eating bacteria ie contaminated rice

What is an endospore and what is it made of?

An endospore is a dormant cell produced by bacteria under harsh conditions and does not have the ability to reproduce. The bacterium, under harsh conditions, can reduce to an endospore in order to survive. (It is made of an existing bacterium).

Clostridium perfringens

Anaerobic endospore-forming bacteria; causes gangrene and skin rotting

Clostridium tetani

Anaerobic endospore-forming bacteria; causes tetanus (toxin causes lock-jaw)

The 2 best-known genera of endospore-producing bacteria are:

Bacillus and Clorstridium

What are endospores resistant to heat and chemicals?

Endospores have tough, outer coating composed of keratin (protein), which allows heat and chemical resistance.

If a basic stain like crystal violet is applied to a bacterial smear that contains endospores (without using steam), what will endospores look like and why?

The endospores will look transparent, because crystal violet is a basic stain that colorizes peptidoglycan layer, not keratin (which is what the outer layer of endospores are made of). Thus, the steam is necessary to weaken keratin layer in order to stain a bacterial smear that has endospores.

Why must extreme measures be taken to stain endospores?

The keratin within outer coat of endospore makes it difficult to stain.

The process by which endospores return to vegetative state is called

germination

Endospores can be differentiated based on shape: they can be _______ or ________

spherical or elliptical

Under what conditions do bacteria produce endospores? What is advantage of endospores to the bacteria?

They produce endospores under harsh conditions like change in pH, extreme temperatures, lack of nutrients, resources, UV light.

What will vegetative cells look like and why?

They will look purple, because during vegetative state, the cell has not formed an endospore, making it easier for the cell to absorb the stain.