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ENZYME PRODUCTION BY YEASTS
Author(s) -
White J.
Publication year - 1956
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.2050-0416.1956.tb02843.x
Subject(s) - maltose , invertase , fermentation , yeast , sucrose , sugar , biochemistry , hydrolysis , food science , chemistry , enzyme , substrate (aquarium) , biology , ecology
The glucose‐fermenting and maltose‐fermenting activities (and in some cases the invertase activities) of yeasts grown in substrates containing various sugars (sucrose, d ‐glucose, invert sugar, beet molasses and maltose) have been estimated at various times throughout the fermentation between the time of initial addition of seed yeast to the medium and the time when all the sugar therein has been used. Certain enzyme adaptations have been found to take place which could have been anticipated; thus, a very high maltose‐fermenting activity was developed in the yeast by growth and fermentation in a maltose solution—indeed, yeasts have been produced giving a greater gas production in maltose than in glucose solutions, supporting the theory that maltose may be fermented directly rather than after a preliminary hydrolysis to glucose. However, in many cases enzyme production has followed a surprising pattern; thus, the degree of ability to ferment maltose and glucose, and also the invertase content of the yeast, often proves to be a function of the stage of harvesting of the yeast crop as well as being influenced by the composition of the substrate.