EXPERIMENT 5 Flashcards
this produces spores
SPORE FORMERS
resistant to heat to any environmental condition
SPORE FORMERS (spore-forming)
This is very difficult to kill with simple physical agent
SPORE FORMERS (spore-forming)
What are the materials used for Growth inhibition and destruction of bacteria by physical agents
Suspensions of Bacillus subtilis and Escherichia coli
Filter paper discs impregnated with Bacillus subtilis and Escherichia coli
Nutrient broths
This cannot resist harsh environmental conditions
VEGETATIVE BACTERIA
How many nutrient broths were prepared for the experiment on Growth Inhibition and Destruction of Bacteria
by Physical Agents
5 nutrient broths on different test tubes
How were the 5 test tubes with nutrient broths labeled
a. Autoclave
b. Hot air
c. Cold
d. boiling
e. Control
What is the purpose of nutrient broths?
They are general purpose broths and used for routine culture. Non-selective (promotes growth of any microorganisms)
Is nutrient broth selective or non-selective
NON-SELECTIVE
When acquiring specimen from liquid suspension what material should be used?
Wire loop
What is the mechanism of action in sterilization with moist heat?
Protein coagulation
Name the three types of sterilization with moist heat?
- Boiling
- Steam under pressure or autoclave
- Fractional / intermittent sterilization
- Pasteurization or tyndallization
What temperature should be used for sterilizing through boiling
100 degrees Celsius
How long should the sterilization through boiling be done?
30 minutes
What are the advantages of using boiling as a sterilization with moist heat method
It is the most inexpensive and the most practical
What is the disadvantage of boiling as the method for sterilization with moist heat?
It is not effective in killing spores
For the suspensions in Growth inhibition and destruction of bacteria by physical agents, what staining was used?
Gram staining
For the control test tube, what temperature should it be incubated at?
37 degrees Celsius
This sterilization method is considered the most powerful heat sterilizing agent
STEAM UNDER PRESSURE or AUTOCLAVE
What is another name of the sterilization method “Steam under pressure”
Autoclave
What temperature should be set when using the autoclave or the steam under pressure method?
121 degrees celsius
How long should the autoclave method be done?
At least 15 - 20 minutes
The amount of pressure to be placed when doing the autoclave method.
15 lbs. pressure
What is/are the advantage/s of using the autoclave method?
a. All microorganisms and their endoscopes are destroyed
b. Shorter time is required compared to the dry heat sterilization
