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Phenol Red Broth
looks for fermentation of sugars (glucose, fructose, sucrose) which is indicated by gas (durham tube) and color change due to acid
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
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.
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
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
Catalase Test
Potent cellular toxins hydrogen peroxide and superoxide radical
Has to w/ ETC- Flavoprotein- Catalase
Bubble- catalse present
No bubble- catalase absent
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
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
2011-02-15T03:01:58Z
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