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SOME COMPARISONS BETWEEN A BACTERIAL AMYLASE AND α‐MALTAMYLASE: PART I. THE KINETICS OF STARCH SACCHARIFICATION BY THE TWO ENZYMES
Author(s) -
Hopkins R. H.,
Kulka Dora
Publication year - 1942
Publication title -
journal of the institute of brewing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.523
H-Index - 51
eISSN - 2050-0416
pISSN - 0046-9750
DOI - 10.1002/j.2050-0416.1942.tb06161.x
Subject(s) - amylase , hydrolysis , enzyme , starch , chemistry , kinetics , food science , biochemistry , physics , quantum mechanics
Bacterial diastases are coming to be much used in industry. A highly purified specimen of such has been investigated and found to resemble very closely in its properties the dextrinising and liquefying component of malt diastase, the α‐amylase. The main point of difference is that the bacterial enzyme can function at higher temperatures than the malt enzyme, and under such conditions it is more powerful than the latter, especially in its rôle of liquefying starch paste. The points of resemblance between the two enzymes are these. (1) They liquefy starch paste and transform starch into dextrins, maltodextrin and a little maltose with great rapidity, this stage of the reaction terminting at about 35 per cent . of the way to complete hydrolysis to maltose. (2) They continue the hydrolysis very slowly from the above stage, until finally coming to a standstill at a stage equivalent to about 90 per cent . maltose. (3) The dextrins produced during the rapid stage of hydrolysis are of widely varying character and include at least one dextrin of reducing power R15 or less, and at least one of R33, presumably maltodextrin.