1. How do the little bugs grow?

2. Outline  Vocabulary warning  Physical Requirements  Chemical Requirements  Patterns of Growth  Measurements of Growth

3. Vocabulary Warning  There is a lot of vocabulary in the next two chapters  Much of the vocabulary is very specific in meaning and descriptive  These terms are extremely relevant to clinical microbiology and are part of the professional lexicon of the field.

4. Physical Parameters of Growth  Like all machines, microbes have operational conditions.  Though microbes dominate every niche on the planet, not all microbes are everywhere.  The physical conditions of growth are directly linked to physiology.

5. Example of Physical Parameters 0° C 10° C 37° C 100° C = Psycrophile = Psycrotroph = Mesophile = Thermophile = Hyperthermophile

6. Other types of physical conditions  Salt concentration Halophile  pH Basophile Acidophile  Water Concentration Xerophile

7. Why do these boundaries exist?  Structural Integrity of Cell Components  Protein Denaturation  Chicken and Egg Problem  Natural Environment of Cells  The Story of Hansen’s Disease

8. Chemical Requirements for Growth.  What elements do we need to form the major macromolecules?  Carbon  Nitrogen  Sulfur  Phosphorus

9. What about Oxygen and Hydrogen?  Both can be gotten from water.  Oxygen is a special case Aerobe – organism that requires oxygen (O 2 ) Anaerobe – organism that does not require oxygen (O 2 )  Modifying Language Obligate Facultative

10. Carbon, Nitrogen, Sulfur, and Phosphorus  Heterotroph vs. Autotroph  Must be present in a usable form  Is this everything you need to make a cell?

11. Other Components  Trace Elements (i.e. metals)  Vitamins  Unique Compounds

12. Types of Media  Complex Media  Defined Media

13. Can we culture everything? NO, many things remain unculturable in today’s micro lab and these are proving to be some of the most interesting organisms.

14. Pattern of Growth = Log Phase = Stationary Phase = Death Phase = Lag Phase

15. Caveats to Model  Small Initial Inoculum  Media can be utilized  Culture is not used to the media  Generation Time, how can you calculate it?

16. Explain this data

17. Measuring Growth  Direct  Indirect