Lysine Decarboxylase broth is recommended for differentiating Salmonella arizonae from the Bethesda Ballerup group of Enterobacteriaceae. During the initial stages of incubation, following inoculation, fermentation of dextrose by the organisms leads to acid production, which causes a subsequent color change of the bromocresol purple indicator to yellow. The acidic condition thus generated stimulates decarboxylase activity, which leads to decarboxylation of lysine to cadaverine. The alkaline conditions generated due to cadaverine production cause the bromocresol purple indicator (changed to yellow) to revert to purple color. If the organisms do not produce decarboxylase enzyme, the color of the medium remains yellow. Dextrose non-utilizers will not show any change in the medium color.
Application: For Laboratory Chemicals, Analytical Purpose, Biochemical Analysis
- Appearance: Light yellow to greenish yellow homogeneous free flowing powder
- Color and Clarity of prepared medium: Purple colored clear solution without any precipitate
- Reaction: Reaction of 1.4% w/v aqueous solution at 25°C. pH : 6.8±0.2
- Cultural Response: Cultural characteristics observed after an incubation at 35-37°C for 18-24 hours.(Inoculated tubes are overlayed with sterile mineral oil)