Putrescine is an alkaline amine that results from which bacterial enzyme?

• A. Ornithine decarboxylase
• B. Lysine decarboxylase
• C. Arginine decarboxylase
• D. Phenylalanine deaminase

Answer: (C)

Putrescine is a polyamine that is notably produced from the decarboxylation of ornithine. The enzyme primarily responsible for this process is ornithine decarboxylase. This enzyme facilitates the conversion of ornithine into putrescine by removing a carboxyl group (CO2), thereby generating an amine from the amino acid.

The question specifically tests knowledge of the metabolism of amino acids into biogenic amines, a key aspect in microbiology and the study of certain bacteria, especially within the Enterobacteriaceae family.

In the context of this question, while arginine decarboxylase would produce agmatine from arginine, and lysine decarboxylase would convert lysine into cadaverine, neither of these pathways contributes directly to the production of putrescine as does ornithine decarboxylase. Phenylalanine deaminase, while involved in amino acid metabolism, relates to a different process and does not play a role in putrescine synthesis.

Thus, the correct answer aligns with the known biochemical pathway where ornithine decarboxylase catalyzes the formation of putrescine from ornithine.