Act 9 Flashcards
(18 cards)
What does the air space in the smaller test tube of a Durham fermentation tube indicate?
GAS production in LACTOSE BROTH
The Durham tube is used to detect gas production during fermentation.
What do homolactic fermenters convert one molecule of glucose into?
Two molecules of LACTIC ACID
These bacteria are commonly used in the fermentation of milk and milk products.
What are the end products of heterolactic fermenters?
CARBON DIOXIDE, ETHANOL, and LACTIC ACID
Examples of heterolactic fermenters include Leuconostoc and Weissella.
What is the pathway of glycolysis called?
EMBDEN-MEYERHOF PATHWAY
This pathway is used by homolactic acid bacteria and yeast.
Which pathway catabolizes glucose to pyruvate and occurs only in prokaryotes?
ENTNER-DOUDOROFF PATHWAY
This pathway is generally utilized by gram-negative bacteria.
What are the end products from the breakdown of glucose during fermentation?
CARBON DIOXIDE or a mixture of HYDROGEN and CARBON DIOXIDE
Hydrogen is insoluble and detected by bubble formation in the Durham tube.
What three sugars are included in the Triple Sugar Iron (TSI) test?
LACTOSE, SUCROSE, GLUCOSE
TSI permits early detection of coliform bacteria that ferment sucrose more rapidly than lactose.
What does a red color indicate in the results interpretation of biochemical tests?
Alkalinization
This indicates that there has been no acid production.
What does a yellow color indicate in the results interpretation of biochemical tests?
Acid Production
This indicates that fermentation has occurred.
What does a black color indicate in the TSI test?
H2S production
H2S is a byproduct of certain bacterial metabolism.
What is the purpose of the IMViC tests?
To differentiate among Enterobacteriaceae
IMViC stands for Indole, Methyl Red, Voges-Proskauer, and Citrate tests.
What reagent is used to test for indole production?
KOVAC’s reagent
A positive result for indole is indicated by a pink color.
What color indicates a positive result for the Methyl Red test?
RED
This indicates the presence of strong acid from glucose fermentation.
What is the positive result for the Voges-Proskauer test?
RED or BROWN
This indicates the formation of acetyl methyl carbinol (acetoin) from glucose fermentation.
What color indicates a positive result for the Citrate test?
BLUE
This indicates that citrate is being used as the only source of carbon.
What is the IMViC result for Escherichia coli?
A/A, +,+, -,-
This indicates the fermentation characteristics of E. coli.
What is the IMViC result for Salmonella?
K/A, +, -, -, +
Salmonella shows specific fermentation and enzymatic characteristics in tests.
What is the IMViC result for Staphylococcus?
A/A, -, +, -, +
Staphylococcus shows distinct fermentation patterns in the IMViC tests.
