| Popis: |
The ability of a brewing yeast to ferment the individual wort sugars, in isolation, changes during a batch fermentation in a manner which reflects the order of removal of the sugars from the wort. These changes are interpreted in terms of the synthesis and degradation of the appropriate enzymes. A survey of the stability of the maltose- utilizing system in yeast showed almost complete loss of aerobic fermentation under de-adapting conditions in all but one of the strains examined. However, in all strains except two of Saccharomyces carlsbergensis in which the maltose permease system is apparently particularly labile, appreciable oxidation of the substrate continued. The loss of power to ferment maltose is associated, in the first instance, with the breakdown of the maltose permease system rather than loss of maltase. |
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