Decarboxylase Agar Base

Decarboxylase Agar Base is recommended for differentiation of bacteria on the basis of their ability to decarboxylate the amino acid added to the medium. Desired L-Amino acids (L-Lysine, L-Arginine, L-Ornithine) can be studied for decarboxylation activity. This medium has Dextrose as the fermentable carbohydrate source. Bromo cresol purple is the pH indicator which changes colour from purple to yellowin acidic condition. Decarboxylase activity is stimulated under acidic conditions and the amino acids are decarboxylated or degraded to form corresponding amine. Production of these amines increases the pH of the medium changing the colour of the indicator and in turn the medium from yellow to purple violet.