Chapter 9-Controlling Microbial Growth in the Environment Lecture notes

  1. Removal or destruction including bacteria, viruses endospores, etc...
    Either in or on an object
    What is the Terminology?
  2. Physical or chemical agent (disinfectant) to inhibit or destroy microorganisms on inanimate objects.  What is the terminology?
  3. Which of the following substances or processes kills microorganisms  on laboratory surfaces?

    C) disinfectants
  4. Types of Disinfectants
    • UV Light
    • Heat
    • Alcohol
    • Lysol
    • Bleach
  5. Refers to the removal of microbes from a surface by scrubbing___.
    ex: washing hands
    alcohol scrub prior to a shot
  6. Environment or procedure is free of contamination
  7. Is the Inhibition/killing of microorganisms on skin or tissue to destroy pathogens
  8. Is the disinfection of plates/utensils in a public setting
  9. Scientists use this suffix to decribe the inhibition of growth metabolism but does not kill microbes.
    ex: Refrigerator=bariostatic
  10. Scientists use this suffix to refer to agents that destroy/kill microorganisms.
    ex: Bacteriacides
  11. The action of antimicrobial agents on the 
    Cell Wall
    Cell Membranes
    Nucleic Acid
    • CW=withstands osmotic pressure if damaged cells burts
    • CM= holds in contents of cytoplama(DNA) & it leaks out
    • Pro= diff functions-3d shape heat, chem. denatures act on ribozomes b/f prot are made
    • Nuc= get altered or destroyed making fatal mutation
  12. This Method dentures proteins
    - integrity of cell membrane/cell well
    -structure/function of nucleic acids
    High Temperature
  13. This method refers to killing all cells in a broth within 10 mins at the Lowest temp
    Thermal death point
  14. This time it takes to kill all cells in a volume of liquid @ a set temp.
    Thermal Death Time
  15. This Heat-related method kills cells by denaturing proteins to sanitize & to pasteurize
    H2O is used because its a better conductor of heat
    Moist Heat
  16. This method kills the vegetative cells of bacteria, but doesn't kill endospores & some viruses
  17. -Steam is heat released
    -uses both high temp & ^pressure to prevent steam from escaping ^ boiling temp
    What is this heat-related method?
  18. This method of heating foods to kill pathogens in milk, fruit juices
    not sterilization
  19. Heat milk to 72°c for 15 sec is called?
    Flash Pasteurization
  20. For substances such as powders and oils that can't tolerate moist heat & requires higher temperatures for longer times than moist heat
    & Incineration is the ultimate means of sterilization
    Dry Heat
  21. An example of dry heat  is the oven that is set on what temp for how long?
    171°c x 1 hr
  22. 1.)This method of controlling microbes consists of temps of 0°c to 7°c &
    2.) this method consisits of temps <0°c
    -no liquid H20 or chemical rxns
    • Refridgeration
    • Freeze
  23. Microbes that are not affected by refridgeration are___ & ____
    • Yersine
    • Listeria
  24. Ice crystals have time to form and puncture cell membranes inhibiting microbial growth is called______ ______.
    Slow Freezing
  25. What are the standard size for a filter?
    0.25um - 0.01 um
  26. What are the 3 examples of Ionizing Radiation?
    • 1.) Electron beams
    • 2.) Gamma Rays
    • 3.) XRAYS
  27. This radiation has high energy, good for killing
    thick meat
    dental/med supplies
    Electron beams
  28. This radiation has deeper penetration
    -longer time 
    -used for meats, spices 
    fruits & vegetables} kills the cells and lets them have a higher shelf life
    Gamma Rays
  29. This radiation has the Deepest perpetrators
    -longest time
    -less energy
Card Set
Chapter 9-Controlling Microbial Growth in the Environment Lecture notes
chapter 9 lecture notes