L-Lysine Decarboxylase Saline Broth (LDC)

L-Lysine Decarboxylase Saline Broth (LDC) is recommended for confirmation of Vibrio species on the basis of lysine decarboxylation from food & animal feeding stuff & enviromental samples in areas of food manufacturing and food handling. The composition and performance criteria of this medium are as per the specifications laid down in ISO 21872-1-2017. This medium is recommended by ISO for biochemical identification of Vibrio parahaemolyticus and Vibrio cholerae on the basis of lysine decarboxylation. Glucose is the fermentable carbohydrate and bromocresol purple is the pH indicator.During the initial stages of incubation, fermentation of glucose by the organisms, with acid production results in a colour change of indicator to yellow. On further incubation, if L-Lysine is decarboxylated to cadaverine, there will be an alkaline reaction and indicator colour will then change to purple. If colour remains yellow, the decarboxylase reaction is negative. Vibrio parahaemolyticus show positive Lysine decarboxylation activity.