1. What are direct methods of measuring growth
  2. Indirect methods of measuring bacterial growth?
    • Trubidity with the use of a spectrophotometer
    • or enzymatic activities
  3. Other ways of measuring bacterial growth?
    Dry weight
  4. What technique can you use to get a pure culture of bacteria?
    Isolation techniques, streak a plate for isolation.
  5. What does a selective media do?
    Selects for one type of bacteria over another.
  6. What does a differential media do?
    It will differentiate differences in bacteria such as formation of lactose.
  7. How is a MSA (Manatol Salt Agar) plate selective and differential?
    • Selective for bacteria that can grow in high salt.
    • Differential for mannitol fermenters,
    • Mannitol fermenters will ferment and release acid that changes the pH indicator in the media from pink to yellow
    • Non mannitol fermenters will not change the color of the media.
  8. How many cells are needed to form a colony on a plate?
    One cell
  9. What is generation time?
    Is the time needed for one cell to divide and become two cells.
  10. Calculation of final concentration?
    Final [ ] = (initial concentration)(2 to the power of # of generation)

    • Example: Final [ ] = (1.0 x 10^2)(2^5)
    • Final [ ] = 3200 cells
  11. Calculation of generation time?
    Generation Time = Time (in min.) / number of generations

    Example: GT = 120min / 10.3 gnenerations

    GT= 11.7 min/generation
Card Set
Measuring Growth Lecture Test 2