MIO MEDIUM 500 grams/bottle

MIO Medium (Motility-Indole-Ornithine) is a semisolid medium used for the differentiation of the Enterobacteriaceae group by motility, ornithine decarboxylase activity and indole production. Gelatin and Casein peptones provide nitrogen, vitamins, minerals and amino acids essential for growth. They also provide tryptophan, needed for the creation of indole. Yeast extract is a source of vitamins, particularly of the B-group; Dextrose is the fermentable carbohydrate providing carbon and energy. L-ornithine is added to test the presence of the enzyme ornithine decarboxylase. If the organisms possesses such enzyme, it will be activated in an acid environment created by the initial fermentation of dextrose. Once the amino acid is decarboxylated, diamine putescine is produced. The result is an alkalinization of the medium, which turns it a dark blue. Organisms without the the enzyme, will remain acidic due to the fermentation, resulting in a yellow color in the medium. Bromocresol purple is a pH indicator to indicate decarboxylase activity; the low concentration of Bacteriological agar is for motility.