EXPERIMENT 21 GELATINASE HYDROLYSIS The connective tissue of vertebrates is called Collagen. If you boil this tissue, the collagen with change into Gelatin, which is a protein. Gelatin is a soluble mixture of polypeptides. Gelatin will be a solid at a temperature of 25oC or lower. Gelatin will be a liquid at a temperature of 26 C or higher. Some microorganisms can liquefy gelatin by producing the extracellular enzyme called “Gelatinase” with the help of hydrolysis. Gelatin is the substrate. Gelatinase is the hydrolytic enzyme. Amino acids are the end-products of gelatin hydrolysis. Gelatin agar deeps are composed of gelatin, beef extract and peptones. This test is performed by placing the gelatin deeps in a 37oC incubator until the gelatin liquefies. Now inoculate the tube with the unknown organism. Place the tube back into the incubator for 48 hours or longer. At the end of the incubation period, place the tube into a 4oC refrigerator for 30 minutes to 1 hour. Observe the tube to see if it is in a liquid or gel state. If gelled, the bacterium does not produce the enzyme Gelatinase. If liquid, the bacterium did produce the enzyme Gelatinase & the test is positive. Once gelatin is degraded into it’s amino acid components, it can never be re- established as gelatin.
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