The roles of enzymes in many processes have been known for long time. Their existence was associated with the history of ancient Greece where they were using enzyme from microorganism in baking, brewing, alcohol production, cheese making etc. With better knowledge and purification of enzyme a number of applications has increased many folds, and with the availability of the enzyme a number of new possibilities for industrial process have immerged. Pullulanase is one such industrially useful enzyme used in the starch processing industries. Pullulanase belongs to α-amylase class of enzymes which is an extracellular carbohydrase which was first discovered by Bender and Wallenfels in 1961 from mesophilic organism Klebsiella pneumoniae (formerly known as Aerobactor aerogenes or Klebsiella aerogenes). Pullulanase are also called de-branching enzyme which hydrolyze the extracellular yeast, polysaccharide and pullulan. It converts pullulan into the trisaccharides, maltotriose. It consists of repeating units of α-maltotriose joined “head to tail” by 1,6-bonds. Pullulanase specifically attack on α-1,6-glycosidic linkage and it also attacks on α-1,4-glycosidic linkage with other residues.