Studies on enzyme action. VIII.—The mechanism of fermentation

In view of the suggestion which has been made that the mechanism of fermentation is, perhaps, to be correlated with that whereby the enzymes effect hydrolysis, it is of importance to ascertain, if possible, the manner in which the activity of the various organisms giving rise to alcoholic fermentation is dependent on or influenced by the enzymes which they contain. The correlation of the activity of an organism with that of its constituent enzymes is of special significance also on the biological side, in connection with the inquiry into the possibility of alterations in the activity of organisms being brought about by changes in their environment. The only systematic investigation made in this direction is that carried out by E. Fischer, who studied the behaviour of most of the known sugars towards a dozen different “pure” yeasts, cultivated from single cells, which (exceptingS. Marxianus and a milk sugar yeast) all contained both invertase and maltase. The conclusion arrived at was that only the four hexoses: glucose, mannose, fructose and galactose are fermentable.