1. Culturing microorganisms, types of culture media, and nutrition. “Bacteria, it’s the only culture I’ve got.” “Without pure cultures all you get is nonsense and Penicillium glaucum” Oscar Brefeld {Bulloch, William. [1938] 1960. The History of Bacteriology. London: Oxford University Press. P192.}

2. Learning objectives Know what a pure colony/culture is. Understand the relationship between growth conditions and growth for aerobes, anaerobes and microaerophilic. Know the difference between selective and differential media.

3. Vocabulary Media/medium—the nutrient material in which bacteria grow. Culture-a bacterial growth in media Pure culture -homogeneous Broth-a liquid nutrient medium Broth culture- a liquid nutrient medium with organisms growing Agar plate- round culture dish with semi-solid nutrient media Slant—tube with semi-solid media, with a slanted surface. Colony– a circular area of limited bacterial growth. Pure colony– a colony thought to contain only the descendants of a single bacterium Strain- a lineage of related bacteria having a certain genetic make-up.

4. More vocabulary Fastidious– fussy. Bacteria that require very strict nutrients. Facultative– able to live in various conditions. Obligate – can only survive under certain circumstances. Aerobe– bacteria that live on oxygen. Anaerobe– bacteria that are inhibited by oxygen. Microaerophilic—bacteria that require low levels of oxygen. Aerotolerant--bacteria that prefer anaerobic conditions but CAN survive in minimal oxygen. Colony morphology– shape, texture, color, size of a colony. Morphotype- group having similar morphology.

5. Types of bacterial growth media and their uses Liquid (broth) --- for expanding an organism Semi-solid—(Agar)  Plates– for pure colony isolation  Slants – for semi-long-term storage and transport.

6. Significance of “pure colonies”  MOST NATURAL SOURCES OF microbes consist of a heterogeneous mixture of many kinds of bacteria. Any study, either research or clinical, requires (homogeneous) pure strains as a start.

9. A. Hesse

11. How many streak phases are evident on the above agar plate? Why not just make a single streak?

13. Stereomicroscope:

14. B. fragilis 2 :

17. Gas-Pac jar: Glove box

18. Candle jar: Aerobic: Gas Pac jar:

20. 1. Obligate aerobe 2. Facultative anaerobe 3. Aerotolerant anaerobe 4. Strict anaerobe

23. Uptake of extracellular nutrients Passive diffusion Facilitated diffusion  Permeases—use concentration gradient Active Transport  Against a concentration gradient + more

25. Nutritional requirements: 1. Major elements: C, O, H, N, S, P. Found in larger molecules. 2. K, Ca, Mg, and Fe found as ions. 3. “Growth factors”(may be synthesized by bug)— amino acids, purines and pyrimidines, vitamins. + specialized.

27. Carbon from carbon dioxide.. 1. Autotrophs—use CO 2. eg photosynthesis. 2. Heterotrophs – use reduced organic compounds. (Energy: Chemotrophs, Phototrophs, Electron sources: Lithotrophs, Organotrophs)

30. E. E. Snell 1914 - 2003

32. Bacteria growing on blood agar Blood agar supports the growth of some fastidious pathogens.

33. Candida parapsilosis on SD agar: Transport media: Sabouraud dextrose plates:

34. Selective vs. Differential media 1. Selective = media that completely inhibits some kinds of growth, either by the omission of critical nutrients or addition of selectively toxic reagents. 2. Differential permits growth of many types of organisms but yields an easily identifiable marker, such as color, to identify certain populations.

35.  hemolysis by S. pneumoniae :  hemolysis by S. pyogenes :

38. Parameters of growth media that need to be regulated for optimal growth. 1. pH 2. Oxygen 3. CO2 4. Temperature 5. Pressure

42. Gas spargers:

46. Expression of chaperones of a psychrophile in E. coli 1

48. Hyperthermophyllic archaeon a.Growth curve

51. Practice test questions Name some microbial nutrients? What is a pure colony/culture ? Describe growth conditions and growth for aerobes, anaerobes and microaerophilic. Know the difference between selective and differential media.

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