Alcoholic fermentation / by Arthur Harden.

  • Arthur Harden
Date:
1932
Catalogue details

Licence: In copyright

Credit: Alcoholic fermentation / by Arthur Harden. Source: Wellcome Collection.

    102/258 page 92
    These factors also occur in many plants, e.g. sprouted barley, green leaves of cabbage or barley, and in many animal organs [Euler and Johansson, 1928]. They are present abundantly in marmite and to a small extent in beer wort. The best source is the dialysate of autolysed bottom yeast. They are much more stable to heat than the co-enzyme and can be separated from it by boiling the solution for one hour at 7, under which conditions the co-enzyme is com- pletely inactivated. They are not precipitated by metallic salts but appear to be in part absorbed by colloidal ferric hydroxide. The characteristic effect is greatly to increase the rate of fermenta- tion by living yeast without increasing the number of cells present. Thus the rate of fermentation of pressed yeast may be increased by IOO per cent, and of Saccharomycodes Ludwigii by 100 to 200 per cent. Nothing is known of the chemical nature or mode of action of these factors. They appear to be quite distinct from any of the other “ bio- catalysts ” of yeast. No pure substance has been found to exert a similar effect on yeast.
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