Pullulanase application

Carbohydrase (Bacillus acidopullulyticus) Produced as an off white to brown, amorphous powder or a liquid by controlled fermentation using Bacillus acidopullulyticus. Soluble in water (the solution is usually light yellow to dark brown), but practically insoluble in alcohol, in chloroform, and in ether. Major active principle pullulanase. Typical applications used in the hydrolysis of amylopectins and other branched polysaccharides. 

The enzyme has not yet been examined in detail. The crude enzyme often contains traces of alpha-amylase. The presence of contaminating alpha-amylase can only be accurately tested for by its effect on the viscosity of linear amylose, and application of this test is essential before the enzyme is used for structural determinations. The crude pullulanase appears to be particularly heat-stable, and, on gel chromatography, two molecular forms, of estimated size 150,000 and 50,000, were obtained. The significance of the two forms is not yet known. The crystallized enzyme has been reported " to have a molecular weight of 145,000. 

Modified substrates may be used in testing the action patterns of purified enzymes. Thus, periodate-oxidized laminaran was used by Smith and coworkers to show the exo action of Basidiomycete (l- 3)-j8-n-glucanase. The oxidized-amylose substrate described earlier (see p. 266) has been used with alpha- and heta-amylases to illustrate how the method is completely general, and applicable to all classes of polysaccharides and poIysaccharidases. ° By use of oxidized pullulan, the endo nature of pullulanase action was confirmed. ... 

A. behaves like starch or amylose in reactions such as ->hydrolysis, derivatization or physical treatment (modified starches). Application of debranching - enzymes (pullulanase and iso-amylase) opens the possibility of total splitting of the a-1,6-linkages, thus enhancing hydrolysis as well as producing short-chain amyloses fit>m a. on a commercial scale. 

When using branched -> starch polysaccharides, additional application of the - debranching enzymes pullulanase or isoamylase leads to increased yields. Entirely soluble substrates can be reacted economically by continuous flow over immobilized enzyme systems. 

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