On fermentation / by P. Schützenberger.

  • Schützenberger, P. (Paul), 1829-1897.
Date:
1883
Catalogue details

Licence: Public Domain Mark

Credit: On fermentation / by P. Schützenberger. Source: Wellcome Collection.

    161/388 (page 149)
    On the whole, this theory throws but little light on the question relating to the very essence of the pheno- menon. Whether the sugar is decomposed with or with- out previous assimilation is of little importance ; \ve are no nearer knowing why it is decomposed, and scarcely any one now doubts that the décomposition of sugar is a biological phenomenon. We must now examine some spécial points relating to alcoholic fermentation. It has been long thought that alcoholic fermentation could take place under two distinct circumstances, ac- cording as yeast is added to a solution of pure sugar in water, or to sugared water containing the nitrogenous and saline principles necessary for its nourlshment. In the first case, it was thought that the ferment acts with- out reproducing itself ; while in the second case, which is that occurring in the brewing of beer, it acts and repro- duces itself More than this, Thénard had observed that, in the fermentation of 20 parts of yeast and 100 parts of sugar, there only remain, after ail the dis- engagement of carbon dioxide has ceased, 137 parts of an insoluble residue, which may be reduced even to 10 by fresh contact with sugar. Thus yeast, while exciting the fermentation of pure sugar, partially destroys itself M. Pasteur, on the contrary, admitting it to be proved by his experiments that the budding and multi- plication of yeast are phenomena which, in a constant manner, accompany ail alcoholic fermentation ; explains the formation of new globules in a solution of pure sugar in water by nutrition at the expense of the nitro- genous soluble substances of the original yeast. In this case, whatever soluble nitrogenous aliment there is in the ferment employed becomes fixed in an insoluble State in the ncwly-formcd globules. It is certain that