EX 5: Growth Inhibition & Destruction of Bacteria by Physical Agents

IN PROGRESS

160 degrees Celsius; 1 hour

What is the temperature & time for “Dry Heat”?

100 degrees Celsius; 30 minutes

What is the temperature & time for “Moist Heat”?

121 degrees Celsius; 15-20 minutes; 15 lbs

What is the temperature, time, & pressure for “Autoclave”?

Protein Oxidation

What is the mechanism of action of dry heat?

Protein Coagulation

What is the mechanism of action of moist heat?

Gay-Lussac’s Law

What is the law applied to autoclaving that states the higher the pressure, the higher the temperature?

Positive Control

What type of control is used in this experiment?

Sterilization eliminates all microbials life, including spores, while disinfection destroys pathogenic organisms but not all microorganisms.

What is the difference between sterilization and disinfection?

Thermal death time is the time required to kill all bacteria at a given temperature, while thermal death point is the temperature required to kill all bacteria at a given temperature.

What is the difference between thermal death point and thermal death time?

1. Mechanical

2. Physical

3. Chemical

3 Ways/Categories of Sterilization

1. Hot Air (Oven)

2. Burning (Incineration)

What are examples of dry heat commonly used in lab?

1. Types of Organisms

2. Number of Organisms

3. Concentration of Disinfecting Agent

4. Presence of Organic Material

5. Nature of Surface to be Disinfected

6. Contact Time

7. Temperature

8. pH

9. Biofilms

10. Compatibility of Disinfectants & Sterilant

Identify the factors that influence the degree of killing bacteria.