Complete and Unabridged.
"Alcoholic Fermentation" by Arthur Harden makes an extensive study of the alcoholic fermentation process, and has made the following observations: The author some years ago found that the juice obtained from yeast by grinding with water can be separated by dialysis into two substances, neither of which alone produces fermentation. The dialysable substance has been called co-enzyme, while the substance remaining on the dialysater was called enzyme. The enzyme proper is activated by the co-enzyme, even when the latter has been heated to a high temperature. These two substances gradually disappear during the fermentation process, the co-enzyme more rapidly than the enzyme. The fermentation stops as soon as the coenzyme is used up, and may be started again by a new supply of the latter. Absolutely necessary for the fermentation is the presence of phosphates. These salts, which are contained in the dialysed liquid, do not remain intact during the fermentation process, but, according to the author, form a new compound, a combination of hexose and phosphoric acid, to which the name hexose-phosphate has been given and the formula C6H10O4(PO4H2)2. This product, which is not precipitated by magnesia mixture, is formed only in the presence of the co-enzyme and enzyme. The author has also made a study of the dioxyacetone CH2OH2CO CH2OH, which can be isolated during the fermentation process, and which he considers as an intermediate product obtained by the reduction [oxidation?] of glycerin.
–Druggists' Circular, Vol. 55