Oxidase Test

Aim
To test the oxidase-producing microorganisms.

Principle
The oxidase determines whether microbes can oxidize certain aromatic amines, e.g., paraaminodimethyl alanine to form a colored end product. This oxidation correlates with the cytochrome oxidase activity of some bacteria, including the genera Pseudomonas and Nisseria. A positive test is important in identifying these genera, and also useful for characterizing the Enterobacteria, which are oxidase-negative.

Materials
  • Glassware
  • Sample culture of Pseudomonas, Bacillus, E. coli., Staphylococcus aureus, and Klebsiella
  • Tetramethyl phenyl diamine
  • Dihydrochloride.

Procedure
  • Plate Method: Separate agar plates streaked with Pseudomonas, Klebsiella, and Bacillus are taken, and 1% reagent tetra methyl phenyl diamine hydrochloride is directly added to the plates.
  • The reactions were observed.

 
Figure 41 Indole test   Figure 42 Methyl red
     
 
Figure 43 Voges-Proskauer (VP) test   Figure 44 Citrate
     
 
Figure 45 Lactose broth   Figure 46 Mac conkey
     
Figure 47 Urease