Amidases are ubiquitous enzymes and biological functions of these enzymes vary widely. Their proteins structures revealed that aliphatic amidases share the typical a/b hydrolase fold (like nitrilase superfamily) and signature amidases are evolutionary related to aspartic proteinases. They hydrolyze a wide variety of amides (short chain aliphatic amides, mid-chain amides, arylamides, α-aminoamides and α-hydroxyamides) and can be grouped on the basis of their catalytic site  and preferred substrate[1].