Which amino acids are utilized in the decarboxylase test?

The decarboxylase test is specifically designed to determine the ability of certain bacteria to utilize amino acids as substrates for decarboxylation reactions, which result in the formation of amines and carbon dioxide. Lysine, arginine, and ornithine are key amino acids involved in this test because they are known to undergo decarboxylation in the presence of specific bacterial enzymes.

In this test, when a bacterium is capable of decarboxylating these amino acids, it leads to an increase in the pH of the medium, typically indicated by a color change if a pH indicator is present. This reaction is crucial for distinguishing certain species of bacteria, particularly in clinical microbiology for identification purposes.

Other amino acids like alanine, glycine, cysteine, serine, threonine, asparagine, glutamate, proline, and methionine do not participate in the classic decarboxylase test reactions, as they either do not undergo decarboxylation in the same way or are not substrates for the decarboxylase enzymes typically assessed in this test. Thus, lysine, arginine, and ornithine are the relevant amino acids utilized in the dec