On expressed yeast-cell plasma (Buchner's "Zymase") / by by Allan Macfadyen, M.D., G. Harris Morris, and Sydney Rowland, M.A. ; communicated by Sir Henry E. Roscoe, F.R.S.

  • Macfayden, Allan, 1860-1907
Date:
[1900?]
Catalogue details

Licence: In copyright

Credit: On expressed yeast-cell plasma (Buchner's "Zymase") / by by Allan Macfadyen, M.D., G. Harris Morris, and Sydney Rowland, M.A. ; communicated by Sir Henry E. Roscoe, F.R.S. Source: Wellcome Collection.

    8/22 (page 255)
    placement of salt solution. The volume of gas evolved is express! in this and the following tables on 100 c.c. of juice, although t. quantity actually used was, as a rule, either 25 to 40 c.c. It will be noticed that in nearly every instance more gas w obtained from the auto-fermentation of the juice than from t fermentation in the presence of cane-sugar. This was usually t] case with the juice from the yeasts of A, C, and D breweries; ho far it is due to the distinctive character of the yeasts or to the hi£ sugar concentration we are at present not prepared to say. Anoth point to be noted is the great variation in the activity of the jui< from different samples of yeast. We noticed this throughout tl whole of our experiments’, but we are unable to correlate it with an of the physical properties of the juice, such as gravity, &c. It wi also be seen that by far the greater part of the action is at an en after twenty-four hours, there being either no further increase in tl amount of gas evolved, or comparatively little. This we also foun common to the majority of our experiments, as will be seen froi subsequent tables. Table I.—Volume of Carbon Dioxide evolved by Cell Juice fron different Yeasts, with and without the addition of Cane-sugar. Carbon dioxide from 100 c.c. of juice. Source of yeast. Age of yeast from collection. After 24 hours. After 48 hours. 1 r .... Alone. With 40 per cent, sugar. Alone. 1 With 40 per cent, sugar. c.c. c.c. c.c. c.c. A* Fresh 520 280 600 472 A* 1 day 240 808 — _ A# 2 days 133 164 — __ A* Fresh 308 186 308 324 A* Fresh 400 228 400 340 A* 1 day 285 270 285 320 A* 1 day 162 84 162 150 Af 2 days 990 234 990 290 Af Fresh 90 170 — _ Af 3 days 760 560 788 592 AJf Fresh 900 2165 _ - A* 5 days 280 220 — _ c# 1 day 550 180 — _ Cf 1 day 540 100 — _ c* 3 days 160 200 — _ A* 7 days 120 200 — _ A* 1 day 65 90 — — * toluol used as antiseptic. f Sodium arsenite used as antiseptic, t In this experiment 10 per cent, cane-sugar was employed.