Starch agar medium was prepared, sterilized and poured in to petri plates. The test culture was streaked on the medium and incubated at 37 C for 24 h. Then place 2 or 3 iodine crystals in the
Petri dish cover. After inverting the plates, iodine gets vaporized.The clear zone outside the area of bacterial growth indicates extend
of starch hydrolysis