4/3 PL Quiz Flashcards
This is a test designed to differentiate bacteria on the basis of fermentative or oxidative metabolism of carbohydrates
Oxidation-fermentation (O-F)
How are organisms oxidized
Glycolysis, oxidation of pyruvate, citric acid cycle, electron transport chain
What does the O-F medium include
High sugar to peptone ratio to reduce the possibility that alkaline products will neutralize weak acids
When is bromothymol blue dye yellow
6
When is bromothymol blue dye green
7.1
When is bromothymol blue dye blue
7.6
What is the OF medium prepared with
Glucose, lactose, sucrose, maltose, mannitol, or xylose
What is one tube of OF sealed with and why
Later of sterile mineral oil to promote anaerobic growth and fermentation
What is the OF test used to do
Differentiate bacteria based on their ability to oxidize or ferment specific sugars
When it is green or blue sealed OF
Oxidation
When it is yellow throughout in sealed OF
Oxidation and fermentation or fermentation only
Slightly yellow at the top of sealed OF
Oxidation and slow fermentation or slow fermentation only
Green or blue sealed AND unsealed of OF
No sugar metabolism
MacConkey agar and EMB agar are selective for what
Gram negative organisms
What does the MacConkey agar contain
Lactose, bile salts, neutral red and crystal violet
