Definition for Gelatin hydrolysis test
From Biology Forums Dictionary
Gelatin, a protein derived from the animal protein collagen. It has been used as a solidifying agent in food for a long time. Robert Koch used nutrient gelatin as an early type of solid growth medium. One problem is that many bacteria have the ability to hydrolyze (liquefy) gelatin. This gelatin liquefaction ability (or inability) forms the basis for this test. Some microorganisms possess an enzyme called gelatinase, which breaks down gelatin into amino acids. Gelatin deeps contain the substrate gelatin, which is a protein produced by the hydrolysis of collagen. Organisms which hydrolyze gelatin will cause the gelatin to liquefy.
The gelatin hydrolysis tests for an organism's ability to break down the protein gelatin which is derived from collagen. Gelatin causes the media to thicken, especially at cooler (below 28°C) temperatures. If the organism can release gelatinase enzymes the gelatin is broken down or liquefied. The media is checked over a period of about a week after inoculation and incubation at room temperature, for gelatinase activity. The tube is placed on ice for a few minutes and if the media fails to solidify it is considered a positive test. The gelatinase reaction may be slow or incomplete.
