Carbohydrate Catabolism Chart Flashcards
What does T S I stand for?
Triple
Sugar
Iron
What is the pH indicator in the TSI test?
Phenol Red
Where does the sulfur source come from in TSI?
Thiosulfate
In TSI what is the H2S indicator?
Ferric ammonium
What are the four things that the TSI test screens for?
(1) Sugar metabolism
(2) Acid Production
(3) CO2 and/or H2 gas production
(4) Hydrogen Sulfide (H2S) Production
What are four possible results in the TSI test and what do each mean?
(1) Yellow color change[A]=Acid production from sugar metabolism
(2) Red color reversion[K]=Production of alkaline wastes from protein digestion
(3) Bubbles and/or cracking=gas production
(4) Black color=H2S production
In the TSI test what are the interpretations based on the slant/butt condition?
- Red/red[K/K]=no growth or aerobic non fermenter
- Red/yellow[K/A]=initial use of glucose but no disaccharide use
- Yellow/yellow[A/A]=Initial use of glucose and secondary use of one or both disaccharides
What do the results of the TSI test allow you to determine?
The presence of the enzymes sucrase and/or lactase
In the Citrate test what is the metabolic energy source?
Citric acid
In the Citrate test what is the pH indicator?
Bromothymol Blue
In the Citrate test what is the nitrogen source?
NH4-(ammonium)
What are two things that the Citrate test screens for?
(1) Presence of enzymes necessary for metabolism of citrate
(2) If an organism can use citrate as its sole metabolic (carbon) energy source
What are two possible results for the citrate test and what do they mean?
Bright blue=(+) organism has used citrate as a nutrient source
(2) Green=(-) organism could not use citrate
What is the end product of a (+) result in the Citrate test?
Sodium carbonate
What enzymes does the Citrate test, test for?
Citrate permease and citrase
In the TSI test at what pH is the yellow color produced?
6.8 or less
In the citrate test at what pH is the blue color produced?
7.6 or above
In the Carbohydrate fermentation test w/ durham tubes what is the pH indicator?
Phenol Red
In the Carbohydrate fermentation test w/ durham tubes at what pH is the lemon yellow color produced?
Below 6.8
In the Carbohydrate fermentation test w/ durham tubes what are the durham tubes for?
Gas collection
What are three things the Carbohydrate fermentation test w/ durham tubes screen for?
(1) The ability for the organism to use a particular sugar as metabolic energy source
(2) The production of acid or alcohol end products
(3) The production of gas during fermentation or aerobic respiration
In the Carbohydrate fermentation test w/ durham tubes what are three possible results and what do they mean?
(1) Lemon yellow[+]=the organism produces acids as fermentation end products
(2) Red/orange=[-]alcohol production from fermentation or aerobic resp. w/no ferm.
(3) Bubbles=gas production primarily CO2
In the Carbohydrate fermentation test w/ durham tubes what does a red/orange tube w/ bubbles mean?
Either sugar fermentation with alcohol and gas or aerobic use and exhaustion of sugar with gas production
What does MR-VP mean?
Methyl Red Voges-Proskauer
