A red color change following the addition of reagents indicates the presence of acetoin, a metabolic byproduct produced by certain bacteria during glucose fermentation. This metabolic pathway distinguishes organisms capable of butanediol fermentation from those that utilize mixed acid fermentation.
This biochemical test plays a crucial role in bacterial identification and differentiation, particularly within the family Enterobacteriaceae. It provides valuable information for classifying microorganisms and understanding their metabolic capabilities, which has significant implications in various fields, including clinical diagnostics, food safety, and environmental monitoring. The test, developed in the early 20th century, remains a standard component of bacterial identification protocols due to its reliability and simplicity.