Ex 9: Endospore Staining Flashcards
What is an endospore?
dormant form of bacterium, allows it to survive poor environmental conditions
What state do endospores exist in?
cryptobiotic state, with no measurable metabolic activity
What bacterium and cell shapes have endospore?
Bacillus and Clostridium. some rods and cocci
When do free endospores remain?
when vegetative cell or sporangium dies
Why are endospores formed?
not for reproduction, but when essential nutrients or water are scarce
What happens to the surrounding cell when endospores are formed?
disintegrate, endspore remains metabolically inert until conditions improve
What is germination?
process in which cell returns to vegetative or growing state
What are endospores resistant to?
harmful effects of heating, freezing, desiccation, UV rays, can survive exposure to acids, bases and disinfectants
How can a stain penetrate the spore coat?
considerable heat is applied
Where are endospores located?
centrally, sub terminally (between centre and end of cell), or terminally
Why does a swollen sporangium result?
diameter of spore is greater than cell’s
What does the Schaeffer-Fulton endospore use as stains?
primary stain- malachite green. decolourizer- water. counterstain- safranin
How will a properly stained spore-former look?
free green endospores or green endospores contained within pink sporangium
What does water do in Schaeffer-Fulton staining?
Rinse malachite green from vegetative state. decolourizer
Name a harmless bacteria that forms endospores
soil saprophytes, organisms that live on dead matter
What does Clostridium botulinum produce?
deadly biological nerve toxin, botulism
What does Clostridium tetani produce?
a toxin that causes rigid paralysis of tetanus
What does Clostridium perfringens produce?
deadly gas gangrene
What does Bacillus anthracis cause?
anthrax, a farm disease that is transmissible to people
What do other Bacillus and Clostridium cause?
food poisoning causing inflammation of stomach and intestines
How are toxins that cause food poisoning released in foods?
normal cooking temperatures leave endospores unharmed, ready to germinate if left a room temperature for too long
Are there any benefits to Bacillus and Clostridium?
are source of many antibiotics
