Enterobacteriaceae Practice Test 2026 - Free Practice Questions and Study Guide

The primary end product detected by the Voges-Proskauer test is acetoin. This test is designed to identify organisms that can produce this specific compound during glucose fermentation. Acetoin is a key intermediate in butanediol fermentation, which is characteristic of certain bacterial species, particularly some members of the Enterobacteriaceae family, such as Enterobacter and Klebsiella.

In the process, if a culture produces acetoin, it will react with alpha-naphthol and potassium hydroxide in the presence of oxygen to form a red color, confirming a positive reaction. This ability to produce acetoin is crucial for differentiating certain bacteria in laboratory diagnoses. Understanding this pathway and the significance of acetoin helps to identify specific metabolic capabilities of different bacterial species within the Enterobacteriaceae family.