Urease

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Urease, an enzyme produced by some microorganisms, attacks the nitrogen and carbon bond in aminde compounds and forms the alkaline end product ammonia

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Microorganism that possess the enzyme urease have the capability of hydrolyzing urea with the release of ammonia andurease carbon dioxide Urea + Water

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Ammonia & Carbon dioxide

Materials: Urea Christensen broth Test organism

Procedures:

Inoculate 5 loopful of the test organism into the urea christensen broth. Incubate at 370C for 24 hours. Observe for color change.

Observation: 

POSITIVE • dark pink color • The pH indicator phenol red changes

to a deep pink color in the presence of ammonia turning the medium alkaline • particularly helpful in identifying Proteus  from other species due to the rapid action of the enzyme by Proteus compared to other nonlactose fermenting enterics • Also (+) to Klebsiella, Haemophilus and Citrobacter

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NEGATIVE • If the medium retains its original color