The soluble ferments and fermentation.

  • Green, J. Reynolds (Joseph Reynolds), 1848-1914.
Date:
1899
Catalogue details

Licence: Public Domain Mark

Credit: The soluble ferments and fermentation. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

    427/504 (page 407)
    but on heating the sohition a pink tint was developed. The solution ol the enzyme had an optical activity of (a)j = + 80\ Destructive analysis showed it to contain 4(i'41 per cent, of Carbon, (jG8 per cent, of Hydrogen, and only 'i*09 per cent, of Nitrogen. In respect of the latter constituent it differed in a remarkable manner from a proteid. A study of the enzyme obtained from yeast-lifjuor in this manner showed that when gradually and continuously decom- posed, chiefly by fractionation with alcohol and acid, it gave rise to a series of bodies, which the authors termed the invertaii series. They prepared and examined seven members of this series, and described their properties under the designations of o, y8, 7, 8, e, ^, and rj invertan respectively, invertase itself being the second member. The two members at the extreme ends of the series, a and rj invertan, were found to be very stable, but the intermediate ones were very liable to spontaneous decomposition. The bodies to which each of the latter gave rise under such circum- stances were invariably a invertan, and the member next below the one dissociated, a invertan itself yielded on decomposition f invertan and yeast albuminoid. Omitting a invertan, each succeeding member was found to possess more stability than the one above it. All the members of the series were non-crystallisable, undialysable, and colourless; a invertan was insoluble in water, but the others dissolved readily, forming clear but viscous solutions which did not become opalescent on boiling. Alkaline or neutral solutions were transformed by the gradual addition of alcohol into a milk-like fluid which would not become clear on filtration, but from which a precipitate rapidly fell on the addition of acid. The a invertan was precipitated in flocculent masses, but the other members separated in the form of heavy transparent syrups. Theii composition, so far as the Carbon, Hydrogen, and Nitrogen are concerned, is given in the following table, in which they are compared also with the yeast albuminoid found in the original yeast-liquor.