GELATIN IRON AGAR

Gelatin liquefaction along with the production of hydrogen sulphide is one of the characteristics used in the classification of bacteria. Hydrogen sulphide can be produced in small amounts from sulphur containing amino acids by a large number of bacteria. Methods to detect hydrogen sulphide production by suspending strips of paper impregnated with lead acetate above cultures are of variable sensitivity and are of limited value. The hydrogen sulphide production test combined with gelatin liquefaction test is useful for group differentiation within the Enterobacteriaceae species. Few Clostridia exhibit gelatinase activity as well as H2S production. Escherichia coli grow well on this medium but show neither gelatinase activity nor H2S production.

for detection of gelatin liquefaction and H2S production