HYDROLYSIS TEST Flashcards
What is the result of a positive hydrolysis test
When these enzymes break down these macromolecules, they produce water.
We can determine whether or not a microorganism produces enzymes for a positive hydrolysis test by whether or not
they can liquify media solidified using these macromolecules
What are the steps to a hydrolsysis test
- Culture sample on a starch-agar plate with your microorganism
- Incubate overnight at 37° C
- Flood plate with Gram’s iodine for 30 seconds. Pour off excess
- Examine cultures. Cultures which can digest starch will appear clear around the streak. This is because iodine dyes starch.
Cultures which can digest starch will appear ________. This is because_______
Will appear clear around the streak
This is because iodine dyes starch.
What are the steps to a gelatin hydrolysis test
- Make a stab culture in nutrient gelatin tube
- Incubate overnight at 37° C
- Examine cultures. Cultures which can digest gelatin will have liquified the media.
Triple Sugar-Iron Agar Test: This test differentiates between different types:
refering to bacteria
Enterobacteriaceae
What are Enterobacteriaceae
are gram-negative bacilli that can ferment glucose
Differentiation between Enterobacteriaceae is possible by examining
differences in carbohydrate fermentation patterns and sulfide production
TSI medium contains
3 carbohydrate sugars (dextrose, sucrose, and lactose),
sodium thiosulfate,
and phenol red
Triple Sugar-Iron Agar Test Results: Red slant, yellow butt, + or – gas production
Only glucose fermentation occurred
Triple Sugar-Iron Agar Test Results: Yellow slant, red butt, + or – gas production
Sucrose and/or lactose fermentation occurred
Triple Sugar-Iron Agar Test Results: Red slant, red butt, no gas
No carbohydrate fermentation has occurred.
Triple Sugar-Iron Agar Test Results: Black butt
Organisms can use sulfur.
Result of H2S production reacting with iron in thiosulfate
Hydrolysis test: Some bacteria produce enzymes that can digest
extracellular materials
Hydrolysis test: Extracellular materials include
Casein
Gelatin
Starch
Lipids