An instance of symbiotic fermentation / by Allan Macfadyen, M.D.

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

Licence: In copyright

Credit: An instance of symbiotic fermentation / by Allan Macfadyen, M.D. Source: Wellcome Collection.

    8/16 (page 212)
    gards results, therefore, remains in the distilling processes usually employed. In the Annales of the Pasteur Institute M. Calmette4 published a paper upon “ La Levure Chinoise,” or the Chinese Yeast. As already stated, the first step in the manufacture of alcohol in European countries is the con¬ version of starch into sugar by the action of an unorganised ferment, the malt diastase, or sometimes by the action of acids. In Eastern countries, however, organised or living ferments have long been used to saccharify the starch, e.g., the Japanese Koji, which is used to prepare an alcoholic beverage from rice, called Sake. The agent in this instance is a mould, the aspergillus orizce, and the saccharified fluid subsequently undergoes a spontaneous alcoholic fermentation in which yeasts take part. The Koji is also used by the Japanese for the preparation of the sauce “ Soy ” and in the making of bread. Takamine has devoted special attention to the study of this ferment and the utilisation of pure cultures of the mould as saccharifying agents.5 Similarly in China and Indo-China a special ferment has been used, which M. Calmette found to be distinct from the Japanese Koji. This “ Chinese Yeast ” consists in the symbiosis of a mould and several varieties of alcoholic yeasts. It appears in commerce as flattened cakes. The recipe for its prepara¬ tion includes about forty-six aromatic ingredients, but no mention is made of the living agents which were introduced into the cake with the rice grains used in its manufacture. The Chinese wTere, therefore, apparently ignorant of the essential factor in their process. As can be readily under¬ stood, such a mixture contained a number of impurities, which could only act deleteriously on the process, as the smell of a sample of the native spirit sufficiently testified. The Chinese add this “ yeast ” to a rice rich in starch, called “Nep.” A saccharification of the starch occurs in three days and an alcoholic fermentation in two days. The liquid is then distilled in a primitive form of apparatus. M. Calmette succeeded in isolating the essential factor from the crude “ Chinese Yeast ” by means of bacteriological methods, using a solid nutrient soil for this purpose, viz.,