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General Information About the Phenylalanine Deaminase Test
General Information About the Phenylalanine Deaminase Test
Phenylalanine deaminase medium tests the ability of an organism to produce the enzyme deaminase.
The Basic Chemistry of Phenylalanine Deaminase Medium
The Basic Chemistry of Phenylalanine Deaminase Medium
Phenylalanine agar, also known as phenylalanine deaminase medium, contains nutrients and DL-phenylalanine. Deaminase removes the amine group from the amino acid phenylalanine and releases the amine group as free ammonia. As a result of this reaction, phenylpyruvic acid is also produced.
Reading the Results
Reading the Results
After incubation, 10% ferric chloride is added to the medium. If phenylpyruvic acid was produced, it will react with the ferric chloride and turn dark green. If the medium remains a straw color, the organism is negative for phenylalanine deaminase production.
When 10% ferric chloride is added to phenylalanine deaminase medium inoculated with Proteus mirabilis, the presence of phenylpyruvic acid causes the media to turn dark green. This is a positive result.
When 10% ferric chloride is added to phenylalanine deaminase medium inoculated with Staphylococcus aureus, no color change occurs. This is a negative result.
Applications of the Phenylalanine Deaminase Test
Applications of the Phenylalanine Deaminase Test
The phenylalanine deaminase test is used to differentiate members of the genera Proteus, Morganella (which were originally classified under the genus Proteus), and Providencia from other Enterobacteriaceae.
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