Starch hydrolysis Aspergillus oryzae

The data show that the extent of the hydrolysis of starch by the amylase of Aspergillus oryzae depends within wide limits upon the concentration of amylase used. Like those for pancreatic amylase already discussed (Figure 2), these hydrolysis curves show a change from a rapid to a slow phase of the reaction and tend to flatten at higher values as the concentration of amylase is increased. Again, with different concentrations of the amylase of Aspergillus oryzae there is no evidence of a common limit such as is observed with different concentrations of beta amylase (Figure 1). 

A Comparison of the Hydrolysis of Soluble Potato Starch by Purified Maltase-free Pancreatic Amylase or Amylase of Aspergillus oryzae (Extent of Hydrolysis as Percent Theoretical Maltose)... 

Taken as a whole, the results indicate that the amylase of Aspergillus oryzae causes the rapid random hydrolysis both of the straight and of the branched chain components of starch and that it hydrolyzes very slowly products with average molecular weights of penta- and tetra-saccharides. 

Studies of the rate of the hydrolysis of dextrins isolated from a reaction mixture after the extensive hydrolysis of starch by maltase-free malted barley alpha amylase, led Myrback11 to conclude that the flattening of the reaction curves with this amylase is not due to equilibrium between the amylase and the products of the hydrolysis. As indicated above, similar conclusions have been reached for pancreatic amylase and for the amylase of Aspergillus oryzae.41,7a... 

Application and Principle This procedure is used to determine the a-amylase activity of enzyme preparations derived from Aspergillus niger var. Aspergillus oryzae var. Rhizopus oryzae var. and barley malt. The assay is based on the time required to obtain a standard degree of hydrolysis of a starch solution at 30° 0.1°. The degree of hydrolysis is determined by comparing the iodine color of the hydrolysate with that of a standard. 

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