Lab Practicum #1 Question Set - 6. Endospore Stain

What is an endospore and what is it made of?

-a dormant cell that survives harsh conditions

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

5-7 days old

What is the difference between an endospore and a vegetative cell?

An endospore is a spore in a capsule that is resistant to harsh conditions which is alive but does not reproduce or produce ATP. A vegetative cell is a cell that germinates and is a metabolically active cell

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

Bacillus Clorstridium

List 4 diseased caused by endospore-forming bacteria and the genus and species of the pathogen that causes each disease.

Food poisoning - Bacillus cereus Anthrax - Bacillus anthracis Lock-jaw - Clorstridium tetani Gangrene - Clorstridium perfringens

The process by which endospores return to the vegetative state is called _______________________.

Germination

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

Harsh conditions such as change in pH, harsh temperatures, dehydration, UV light This protects the cell, prevents damage to DNA, prevents loss of nutrients

What will the vegetative cells look like and why?

Purple. The endospore is not formed around the cell when in vegetative form, and the cell can easily absorb the stain.

Why must extreme measures be taken to stain endospores?

The keratin in the spore coat resist staining

Name and describe 3 possible locations for endospores in the cell.

central = middle terminal = end of cell sub-terminal = between the middle and the end of cell

Why are endospores resistant to heat and chemicals?

due to a tough outer coating made of a protein called keratin, its DNA protective proteins and its dehydrated state.

Endospores can be differentiated based on shape: they can be _______________ or ________________.

spherical; elliptical (oval)

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

up to 50 years

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

Transparent. Crystal violet is a basic stain that cannot break through the cell wall and penetrate in order to stain the cell.