micro...

  1. Phenol Red Broth
    looks for fermentation of sugars (glucose, fructose, sucrose) which is indicated by gas (durham tube) and color change due to acid
  2. Color indication phenol red broth
    • Yellow broth w/ bubble is acid and gas end products
    • Yellow broth no bubble is acid but no gas
    • Red broth no fermentation
    • pink broth is alkaline end product
  3. Oxidation fermentation test
    • carbohydrates are oxidized to pyruvate
    • low agar concentration
    • 2 tubes stab inoculated
    • after inoculaton 1 tube place mineral oil
    • the other leave unsealed.
  4. Oxidation fermentation test
    • yellow throughout is oxidation and fermentation or only fermentation
    • green/blue (w/ any amount of yellow) oxidation
    • slightly yellow on top is oxidation and slow fermentation or only slow fermentation
    • green/blue (no yellow) is no sugar metabolism
  5. Methyl Red and Voges-Proskauer Tests (MR &VP)
    • Combo medium
    • MR= detects organisms capable of performing a mixed acid fermentation.
    • verified w/ methyl red indicator. red= + result, acidic
    • VP= organism ferment glucose quickly convert products to aceotoin and 2,3 butendoil red= + result alkaline
  6. Catalase Test
    • Potent cellular toxins hydrogen peroxide and superoxide radical
    • Has to w/ ETC- Flavoprotein- Catalase
    • Bubble- catalse present
    • No bubble- catalase absent
  7. Citrate Test
    • In many bacteria citrate produced as acetyl Co A reacts w/ oxaloacetate at entry Krebs
    • only available carbon source
    • pyruvate converted by citrate- permease
    • Ammonia phosphate sole nitrogen source
    • agar called simmons citrate agar
  8. Citrate Test color indicators
    • Blue (even a samll amount) is citrate utilized
    • no color change but growth is citrate utilized
    • No color change and no growth is not utilized
Author
ski4me18
ID
66395
Card Set
micro...
Description
phenol red broth, oxidation fermentation test, MR and VP test, Catalase test, citrate test
Updated