Alcoholic fermentation / by Arthur Harden.

  • Arthur Harden
Date:
1932
Catalogue details

Licence: In copyright

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

    78/258 page 68
    [Neuberg and Leibowitz, 1927, 2], and by kidney phosphatase [Neuberg and Leibowitz, 1927, 4], and one of the phosphoric acid groups of hexosediphosphate is much more rapidly removed than the other by muscle phosphatase [Robison, 1923, see also Brugsch, Cahen, and Horsters, 1925]. An interesting feature of these changes is that yeast gives a mixture of the Neuberg and Robison mono-esters and kidney diastase almost pure Robison ester, whilst taka-diastase and yeast in presence of arsenate (and chloroform and toluene) give almost pure Neuberg ester. This affords another instance of the labile character of the sugar residue in these compounds. Similarly the hexose obtained by the hydrolysis of hexosediphos- phate with bone phosphatase is much less laevo-rotatory than fructose [Martland and Robison, 1929]. By the action of bottom yeast on the Robison ester Neuberg and Leibowitz [1927, 2] obtained hexose- diphosphate which they consider was formed by enzymic synthesis from the monophosphate, but it seems also possible that it may have been produced from a hexose liberated by hydrolysis. The hexosemonophosphates are themselves hydrolysed (and fer- mented) by yeast preparations, and the Robison ester and its aldose constituent are readily hydrolysed by bone phosphatase [Robison, 1923] as is the Neuberg ester [Takahashi, 1924, 2 ; Fujihara and Koken, 1926], which is also hydrolysed by the phos- phatase present in many animal organs and tissues [Tomita, 1922]. Some discussion has taken place with regard to the influence of the co-enzyme on the action of the hexosephosphata.se of yeast on hexosediphosphate. Raymond [1928], comparing the action of washed and unwashed zymin, concluded that the co-enzyme was involved in the reaction but this has not been confirmed by Macfarlane [1930], who finds that a preparation made by the autolysis of dried baker’s yeast and free from co-enzyme and apozymase, i.e. unable to esterify phosphoric acid and sugar and produce C02 and alcohol even in presence of added co-enzyme, hydrolyses hexosediphosphate readily, and further that the rate of hydrolysis is not affected by the addition of co-enzyme. The Equation of Alcoholic Fermentation. Before it was realised that the hexosediphosphate produced during alcoholic fermentation was accompanied by a hexosemonophosphate, Harden and Young proposed the equation, 2C6h12o6 + 2P04hr2 = 2co2 -f- 2C2h6o -j- 2H2o -f- C6H10O4(PO4R2)2, to represent the change which occurs.
    digitised image 1
    digitised image 2
    digitised image 3