Indole Test
This test demonstrates the ability of certain
bacteria to decompose the amino acid (tryptophan) to
indole, a volatile substance that rises and accumulates at
the surface of the medium. The isolates were grown for
24-48hrs on peptone water at 370C then 0.5ml of the
Kovac’s reagent was added to the culture inside the
test-tube which was shaken gently. Production of indole
was confirmed by the formation of red ring colouration
on the surface of the medium. An indication of the
reaction between the produced indole and Kovac’s