After touching several well-isolated colonies with a sterile needle, stab directly down the center of the tube to approximately 10 mm from the bottom. The medium should be solidified at room temperature. Incubation temperatures vary according to the nature of organisms e.g for Enterobacteriaceae and fluorescent Pseudomonas 22☌ and for non-fermenting, gram-negative rods 30☌.Negative Control : Escherichia coli ATCC 25922 Procedure of G elatin Liquefaction Test
Positive Control: Pseudomonas aeruginosa ATCC 10145 Requirement for Gelatin Liquefaction Test This enzyme destroys the structure of the gelatin, and it becomes liquid. Gelatinase is a proteolytic enzyme that hydrolyzes gelatin into polypeptides and individual amino acids. It is a protein derived from the animal protein collagen– a component of vertebrate connective tissue. It is nowadays replaced by agar due to having better-solidifying properties than gelatin but even in use for gelatin liquefaction test to identify various organisms like Bacillus, Clostridium, Proteus, Pseudomonas, and Serratia. Gelatin is a solidifying agent and is used in microbiology for culture media before the use of agar. Introduction of Gelatin Liquefaction Test
