E10B Flashcards
Used to detect the ability of an organism to produce the enzyme Gelatinase (proteolytic) which digest the
gelatin present in the medium.
Gelatin Hydrolysis Test
It is a protein from collagen & its hydrolysis indicates
presence of the enzyme
Gelatin
Gelatin Hydrolysis indicates presence of?
enzyme
In Gelatin Hydrolysis Test, gelatin > ____ > ____
- polypeptides
- amino acids
In Gelatin Hydrolysis Test, the end-products are used for ?
metabolism
In Gelatin Hydrolysis Test, if the result is the medium must stay liquefied even after exposure to cold temperature (4°C), it means the result is?
positive
In Gelatin Hydrolysis Test if the result is complete solidification of the medium after exposure
to cold temperature, it means the result is?
Negative
Determines the ability of an organism to split amino acid tryptophan to form the compound indole.
Indole Test
In Indole test positive resul is
Pink colored rink after
addition of Kovac’s Reagent.
What is the Kovac’s Reagent?
4 (p)-dimethylamino-benzaldehyde
To determine whether the organism is able to reduce nitrate to
nitrite and subsequently ammonia or reduce it to nitrous acid.
Nitrate Reductase Test
To differentiate members of Enterobacteriaceae that produce
enzyme nitrate reductase from those that do not
Nitrate Reductase Test
In Nitrate Reductase Test,
(+) sulfanilic acid (A) > ____
diazotized sulfanilic acid
In Nitrate Reductase Test,
(+) α-naphthylamine (B) → ____
RED azo dye (prontosil)
2 possible reasons for absence of red color in nitrate reduction test:
- Strain is nitrate-negative
- Strain is nitrate-positive
The ammonia produced is used by the cells for the synthesis of
amino acids and other nitrogenous compounds.
Assimilation
Nitrate or nitrite is used by the organism primarily for energy
metabolism. Nitrate/nitrate serves as the final electron acceptor in
the absence or reduced presence of free oxygen.
Dissimilation
Certain bacteria convert nitrate to gaseous products like nitrogen and nitrous acid
Denitrification
This nitrate reacts with the reagent A and B to give red color due to the
formation of ____
Azo dye.
Color of positive result of Nitrate Reductase Test
Red
To check whether the organism can produce urease enzyme for the degradation of urea or not.
Urease Test
Contents of Urease Test
- Urea
- Phenol Red (pH indicator)
It catalyzes the breakdown of urea into ammonia and carbon dioxide.
Urease
[Urease Test], With the release of ammonia, the medium becomes alkaline and
changes its color into _____.
pink-red
It is composed of materials most bacteria require for growth
Milk
Milk materials required for growth.
- Milk protein casein
- sugar lactose
- vitamins
- minerals
- water
a pH indicator, is incorporated to determine acid or alkali
production, and oxidation and reduction activities
Litmus
The characteristic reactions observed of Litmus Milk Test
- Lactose fermentation
- Alkaline reaction
- Curd formation (acid curd and rennin curd)
- Litmus reduction
- Proteolysis (peptonization)
- Gas formation
- Acid production
Litmus milk medium results of no fermentation
A
Litmus milk medium results of acid reaction (lactose fermented)
B
Litmus milk medium results of curd formation (protein coagulation)
C
Litmus milk medium results of clearing of medium (whey formation)
C
Litmus milk medium results of cracks in curd (gas formation)
C
