Production of a Fermentable Sugar from Hexosephosphate by the Action of an Enzyme Contained in Yeast-Juice.
The sugar which, according to equation (2) accompanies the phosphate formed by the enzymic hydrolysis of hexosephosphate is under ordinary circumstances fermented by the alcoholic enzyme of the juice and thus escapes detection.
When, however, a solution of a hexosephosphate is exposed to the action of either yeast-juice or zymin, entirely or partially freed from co-enzyme, this sugar, being no longer fermented, accumulates and can be examined. It has thus been found [Harden and Young, [1910, 2]] that a sugar is in fact produced in this way which can be fermented by living yeast and exhibits the reactions of fructose, although the presence of other hexoses is not excluded. The products of the enzymic hydrolysis of the hexosephosphates therefore appear to be the same as, or similar to, those formed by the action of acids [Young, [1909]].
A further consequence of these facts is that a hexosephosphate will yield carbon dioxide and alcohol when it is added to yeast-juice or zymin, and this has also been found to be the case [Harden and Young, [1910, 2]; Iwanoff, [1909, 1]]. [p057]