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.

    117/388 (page 105)
    dilute sulphuric acid, into fermentable sugar ; there was also a sensible augmentation of nitrogenous matter, insoluble in dilute sulphuric acid. On the other hand, in order to verify, by a second experiment, the value of these conclusions, M. Pasteur made use of the process of separating cellulose from the albuminoid substances indicated by Payen and Schloss- berger. This process consists, as is well known, in treating yeast with dilute solutions of potass. In three careful experiments, M. Pasteur found a residuum, insoluble in potass, formed of cellulose, trans- formable into sugar by being boiled with dilute sul- phuric acid of 1777, 19-29, and 19-21 per cent, of the dry yeast experimented on. But the 0-532 grammes of sugar, produced without the intervention of potass, by 2-626 grammes of the same yeast, correspond to 20 per cent, of yeast. It is, therefore, proved that boiling in sulphuric acid had removed ail the cellulose. Let us also notice that the 2-965 grammes of yeast found after fermentation, giving 0-918 grammes of sugar, ought to contain 31-9 per cent, of cellulose, a quantity 11 per cent, greater than there was before fermentation. This considérable augmentation of the weight of the cellulose in the yeast, while it exercised its action on the sugar, is a point worthy of remark, since it proves that, in accomplishing one of its principal functions, yeast undergoes very marked évolutions in its composition. The following experiment of M. Pasteurs proves, besides, that during fermentation the yeast itself forms its fatty matter by the help of the éléments of sugar.