Pullulanase Aerobacter aerogenes

Kinetic studies have been completed on an immobilized enzyme system containing /8-amylase and Aerobacter aerogenes pullulanase that is used for the continuous production of maltose from starch. ... 

Pullulanase Enzyme degrading pnUnlan, a branched starch pullulanase catalyzes the hydrolysis of the a-l,6-glncosidic linkage in a-glucans. Pullulanase preferentially hydrolyzes pnUnlan while isoamylase has a preference for glycogen and amylopectin. See WaUenfels, K Bender, H and Rached, J.R., Pnllnlanase from Aerobacter aerogenes production in a cell-bound state. Pnrification and properties of the enzymes, Biochem. Biophys. Res. 

Pullulanase is an extracellular enzyme of Aerobacter aerogenes that causes essentially quantitative hydrolysis of pullulan to maltotriose. The enzyme is readily prepared in a crude form that is free from other carbohydrases, and is important in structural studies because it debranches amylopectin and glycogen. When the A. aerogenes is grown in continuous culture, the enzyme is bound to the cells, but it can be released by detergents, and purified by ion-exchange chromatography. This purified enzyme has been crystallized. ... 

The discovery, shortly thereafter, of the enzyme pullulanase from the bacterium Aerobacter aerogenes helped considerably in further structural analysis of the polysaccharide. Hydrolysis of pullulan by diis enzyme showed that essentially no products containing (l->6)-ff-i>-giucosidic linkages were formed, the preponderant product being maltotriose. It was thus clear that the enzyme hydrolyzes (l->6)-a-D-glucosidic link-... 

Pullulanase was obtained originally from Aerobacter aerogenes fermentation by Bender and Wallenfels in 1961. In 1975, Yoshiyuki Takasaki foimd that the... 

The purification of pullulanase from Aerobacter aerogenes via affinity chromatography on an agarose-immobilized cyanogen bromide-activated cyclohexa-amylose has been reported. Elution from the affinity column was achieved using cyclohepta-amylose. Crossed immunoelectrophoresis was used to follow the various steps of the purification. 

Some properties of crystalline extracellular pullulanase from Aerobacter aerogenes were compared with those of crystalline intracellular pullulanase. The amino-acid compositions of these enzymes were found to be alike on the... 

Haltohexaose-producing Amylases. Both endo- and exo-amylases that produce maltohexaose from starch have been identified and characterized. The exo-acting enzyme was first discovered as a cell bound enzyme in "Aerobacter aerogenes (now called Klebsiella pneumoniae), an organism better known for pullulanase synthesis. The enzyme is stable at temperatures lower than 50< C and has an optimum pH for activity around neutrality (39). Escherichia coli, long thought to be devoid of amylase activity, has been shown to synthesize a similar enzyme (40). These enzymes are periplasmic and synthesis is induced by the presence of maltose (40). 

A pullulanase in E. coli appears to be bound to the cell wall its properties are very similar to those of a pullulanase from Klebsiella (Aerobacter) aerogenes. However, no pullulanase activity was detected in cultures of E. coli grown on maltose. Neither this nor forty other strains of E. coli grew on pullulan, whereas all the strains grew on maltose, and some on maltotriose. The synthesis of pullulanase by various strains of Klebsiella (Aerobacter) aerogenes using maltose both as an inducer and as a source of carbon has been studied." Conditions leading to the synthesis of pullulanase were reported. 

Pullulanase Aerobacter aerogenes Increase of fermentability of starch worts or syrups. 

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