POLYSACCHARIDE S 



111 



least in its early phases, results in the formation of dextrins, reducing 

 sugars appearing only later. 



2. Beta-amylase (exoamylase, saccharifying amylase) of resting seeds. 

 Attack on starch liberates maltose immediately. 



It has been repeatedly found, with highly purified or crystalline 

 preparations, that the amylase of Aspergillus oryzae is of the a-amylase 

 group (49, 73, 235). So also, apparently, is the amylase of Streptomyces 

 spp. (213). The crude amylase of A. oryzae contains more than one 

 component, as judged by electrophoretic data (82). 



The enzyme of Rhizopus delemar, termed glue amylase (177, 178), 

 can be separated from a-amylase and resembles /^-amylase in certain 

 respects. There seems, however, no reason to believe that a typical 

 ^-amylase occurs in the fungi (127, 129, 146). 



Table 2 summarizes some of the properties of the purified amylase 

 of Aspergillus oryzae and its differences from other a-amylases. 



Amylase activity, defined as the ability of cell-free materials to 

 hydrolyze starch or glycogen, is virtually universal in the fungi and 

 actinomycetes. Penicillium digitatum does not form detectable 

 amylase in culture (103), and in view of its inability to grow on starch 

 (Chapter 3) is presumably deficient for the enzyme. Early studies on 

 fungal amylase are summarized by Thaysen and Galloway (230), and 

 the industrial technology of the enzyme is reviewed by Langlykke 

 et al. (123). 



Table 2. Properties of Alpha-amylases (74) 



Source of Crystalline Alpha-amylase 



Activity per mg N 

 Activity per mg protein 

 Nitrogen, per cent 

 Optimum pH for activity 

 Optimum pH for stability 

 Isoelectric point 

 Absorption maximum (m/x) 

 Saccharogenic/dextrinogenic 



ratio 

 Activation by Ca 

 Activation by CI 

 Energy of activation 



