Casein Hydrolysis/Phenylalanine Deaminase Test

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Casein Hydrolysis/Phenylalanine Deaminase Test
2014-04-03 14:32:29
Microbiology Casein Hydrolysis Test
Micro Lab
Casein Hydrolysis Test (Practical exam 2)
Show Answers:

  1. What type of agar is used in Casein Hydrolysis test?
    • Milk Agar Plate
    • -Casein (protein found in milk)
  2. What enzyme breaks downs casein?
    An exoenzyme named Casease
  3. Describe what is happening in this test.s
    E Coli is (-) for the enzyme casease, therefore is unable to breakdown the casein in milk ager into smaller peptides & amino acids

    B. cereus is (+) for the enzyme casease, therefore is was able to break down the casein into small peptides & amino acids for cell use
  4. What does a Phenylalanine Deaminase Test determine?
    Tell you if a cell is capable of producing a an enzyme called deaminase.
  5. If an organism is (+) for enzyme deaminase what happens?
    It strips the amine group (NH2) from the  phenylalanine agar creating phenylpruvic acid.
  6. How to tell is an organism is (+) for deaminase
    You add 4 drops of ferric chloride (FeCl3).

    • (+) for deaminase turns green
    • (-) for deaminase stays the same color
  7. Deamination
    The removal of an amine group (NH2) from phenylalanine(AA)
  8. If an organism is (-) for deaminase, and you add 4 drops of ferric chloride
    It turns yellow which mean no phenylpyruvic acid/ No phenylalanine deaminase enzyme
  9. What test is this, what is it looking for, what does it mean? 
    • Phenylalanine Deaminase Test
    • Green = Positive for Phenylalanine Deaminase
    • Yellow/Same color = Neg for Phenylalanine Deaminase 

    Ferric Chloride is used to detect any Phenylpyruvic acid that is made. If organism has the enzyme to break down phenylalanine = positive
  10. What is Phenylalanine?
    Its an Amino Acid

    When deaminated the amine group NH2 is removed