Decarboxylase Test- Principle, Procedure, Results, Uses

Decarboxylase Test

Decarboxylase Test Definition Decarboxylase test is a biochemical test performed to differentiate members of Enterobacteriaceae on the basis of their ability to produce the enzyme decarboxylase. The metabolism of amino acids might differ in aerobic and facultatively anaerobic bacteria as well as in gram-negative organisms. Metabolism of amino acid might occur either by decarboxylation, hydrolysis, or deamination, depending on the …

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Citrate Utilization Test- Principle, Procedure, Results, Uses

Citrate Utilization Test- Principle, Procedure and Result Interpretation

What is Citrate Utilization Test? The citrate utilization test is a part of the IMViC test (Indole, Methyl Red, Vogues-Proskauer, and Citrate Test) that differentiates organisms on the basis of their ability to use citrate as a sole source of energy. The citrate test is performed along with the other IMViC tests to differentiate Gram-negative bacilli of the Enterobacteriaceae family. …

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Enterobacteriaceae Cultural Characteristics

Enterobacteriaceae Cultural Characteristics

Image Source: Cole-Parmer Instrument Company. Cultural Characteristics of Citrobacter freundii Citrobacter freundii on Nutrient Agar Smooth, convex, translucent, or opaque grey colored with a shiny surface and entire margin; mucoid or rough colonies occasionally. Citrobacter freundii on Blood Agar Circular, flat, entire red colored colonies. Citrobacter freundii on Mac-Conkey Agar Pink colored after 24 hr incubation; pale-colored colonies turn pink …

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Sulfur Reduction Test

Sulfur Reduction Test

Objectives To determine the ability of the organism to reduce sulfur for the production of hydrogen sulfide. To differentiate members of Enterobacteriaceae, especially the sulfur-reducing Salmonella and Proteus from the non-reducing Morganella morganii and Providencia rettgeri. Principle The Sulfur Reduction Test is performed using the SIM medium. SIM medium also tests for indole production and motility. It is a semi-solid …

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