Starch Hydrolysis Test Flashcards

Starch Hydrolysis Test Overview

• Starch is a large carbohydrate composed of numerous glucose subunits that require breakdown for bacterial utilization.
• Amylase is the enzyme responsible for hydrolyzing bonds between glucose units, facilitating starch digestion by bacteria.

Medium and Procedure

• The test is conducted on Starch Agar plates, which contain starch that dissolves completely in water, making it clear.
• Iodine is used to visualize starch presence after incubation; it forms a dark blue/black complex with intact starch while remaining amber where starch is broken down.

Interpretation of Results

• A positive Starch Hydrolysis test shows an amber color around bacteria after iodine application, indicating the presence of amylase.
• A negative test appears dark blue/black, signifying intact starch and the absence of the amylase enzyme.

Test Steps

• Streak organisms in a straight line on the Starch Agar Plate.
• Incubate at 37°C until the next class.
• After incubation, coat the agar surface with Gram's Iodine and observe the results.

Key Reagents

• Gram's Iodine serves as the reagent to detect the presence of starch on the agar plate.