Alcoholic fermentation / by Arthur Harden.

  • Arthur Harden
Date:
1932
Catalogue details

Licence: In copyright

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

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    Substance. Concentrated solution of glycerol >> ... ,, sugar . Toluene (to saturation or excess) Chloroform 0-5 per cent. . »» o-8 „ (saturation) ,, large excess (17 per cent.) Chloral hydrate 0*7 per cent. >> 3*5-5‘4 Per cent Phenol o-i per cent. Thymol y > Benzoic acid t y Salicylic acid y y Formaldehyde y > Acetone y y Alcohol o-5 1*2 I 5 o-i 0-25 o-i 0-27 0-12 0-24 6 14 6 14 Sodium fluoride 0-5 > > 2 ,, Ammonium fluoride 0-55 per cent. Sodium azoimide, NaN3 0-36 per cent. >> ’> 0-71 ,, Quinine hydrochloride 1 ,, Ozone 10-4-34-8 milligrams per 20 c.c. Hydrocyanic acid 1-2 per cent. . Effect on Total Fermentation. Slight diminution „ increase Less than 10 per cent, diminution Slight increase No change 64 per cent, diminution Increase up to 27 per cent. Completely inhibited No change 40 per cent, diminution Completely inhibited Slight diminution Marked 7 26 10 35 per cent, diminution >> i> >> >> > > 20 30-60 20 80 0-20 y y y y y y y y y y y y y y y y y > y y 75 >> >> 99 Almost completely inhibited Completely inhibited Slight diminution Marked Slight increase Marked diminution Completely inhibited The general result of these experiments is to show that quantities of antiseptics which are sufficient to inhibit the characteristic action of living cells have only a slight effect on the fermentative activity of yeast-juice. A large excess of the antiseptic in many cases produces a very decided diminution or total destruction of the fermenting power, and accompanying this a precipitation of the constituents of the juice. The decided increase of activity produced by small quantities of chloral hydrate, and to a less marked extent by chloroform and a few other substances, is of considerable interest. It is ascribed by Duchacek to a selective action on the proteoclastic enzyme, but with- out satisfactory evidence. The effect of some of these substances on the various reactions involved in alcoholic fermentation, such as the esterification of phosphoric acid, the action of hexosephosphatase, etc., has also been determined (see Chapter VIII.). Hydrocyanic acid, even in dilute solution, completely suspends the fermenting power of the juice, without, however, producing any permanent change in the fermenting complex, as is shown by the fact that when the hydrocyanic acid is removed by a current of air, the juice regains its fermenting power. In this respect therefore hydro- cyanic acid behaves as with certain other enzymes and with colloidal platinum [Bredig, 1901]. Sodium arsenite is a pronounced proto-
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