Lab 7:  Objectives

Concepts:  Quizzes and Practicals

1. Define and be able to apply the following:
   1. Osmotic pressure
   2. Plasmolysis
   3. Thermal death time
   4. Thermal death point
2. Know what concentration of salt an extreme (obligate) halophile and a facultative halophile grow best at, can tolerate and/or require to grow.
3. Effects of hypo-, hyper-, and iso- tonic solutions on non-halophilic cells and halophilic cells.
4. Know why E. coli cannot grow in media containing high salt concentrations.
5. Know the optimal salt concentrations for each of the following organisms:
   1. E. coli (not a halophile)
   2. S. aureus (facultative halophile)
   3. H. salinarium (extreme halophile)
6. Why is Bacillus resistant to death by boiling?
7. What is pasteurization?  What temperature and how long?
8. Describe how you can determine the thermal death time.
9. What is an effective way of sterilizing a sporulating culture?

Identification:  Practicals

1. What does each of the following looks like: 
   1. – growth
   2. + growth
   3. ++ growth
2. Be able to identify extreme halophiles, facultative halophile (halotolerant) on non-halophiles via their growth properties in various media.