1. To supply the growth requirements
Culture Media
To supply the growth requirements

2. overview of cell metabolism:
catabolic: energy releasing
anabolic: energy requiring
macronutrients include: C, N, P, S, K, Na
micronutrients : Ca, Mg, Fe
Trace elements, B, Zn. Cr, Co, Cu, Mn, V, W
Growth factors: vitamins

3. phototrophs: light as energy source
Recall: energy classes of microorganisms
phototrophs: light as energy source
chemotrophs: chemicals as energy source
chemoorganotrophs: organic chemicals
chemolithotrophs: inorganic chemicals

4. Culture Media Defined: made from purified chemicals
e.g., glucose-mineral salts broth
Complex (undefined): exact chemical composition not known
e.g., YE (yeast extract) agar
Enriched extra range of nutrients eg Blood agar
agar – polysaccharide derived from algae
forms a gel at temperatures of interest, including 37ºC
not many microorganisms can degrade it
widely used as solidifying agent in microbial media

11. aseptic transfer:

12. Liquid
Solid

13. streak plate:

14. Types of Agar Media Enriched media Differential and selective media
Contain growth factors and other complex organic substances like blood, serum, etc
Better for FASTIDIOUS bacteria
Differential and selective media
Powerful tools in clinical lab
Some can give preliminary ID of bacteria

17. Differential Media

18. Selective Media
Mannitol Salt Agar
MacConkey Agar

19. Miscellaneous Media
Examples of miscellaneous media are reducing, fermentation and transportation media.