Abstract
Direct debranching enzymes can attack amylopectin and glycogen. They are principally divided into isoamylase and pullulanase. In this paper, distribution, production, properties and application of the enzymes are described. Distribution of isoamylase is quite limited in bacteria, but pullulanase seems to occur widely in different kinds of bacteria. Isoamylase can split all the branching points of glycogen, but not those of pullulan whereas pullulanase can split pullulan completely, but has limited hydrolytic activity on glycogen. There are several differencesin the modes of decomposition of starch by isoamylase and pullulanase. Isoamylase is produced in high yield by a mutant strain of Pseudomonas amyloderamosa SB15 and shows very high specific activity towards starch. Pseudomonas isoamylase is preferable to Klebsiella pullulanase for the production of glucose or maltose from starch in the combination with glucoamylase or β-amylase . Bacillus pullulanase seems also to be useful for the purpose.
