
1905.| On the Probable Existence of Emulsin in Yeast. 575 
lytic enzyme of yeast resembles trypsin in its action. (Compare also Hahn 
and Creret.*) 
Lffect of Antiseptics on the Glucosidolytic Action of Yeast. 
The activity of the glucosidolytic constituent of the yeast is not affected by 
antiseptics, and in this respect, as also in its behaviour towards dilute mineral 
acids and alkalis, by which its action is totally inhibited, it resembles the 
emulsin of almonds. 
The experiments recorded in the following table were carried out under 
comparable conditions at 40°. In each case 1 gramme of amygdalin was 
used, and the hydrocyanic acid formed was estimated by Liebig’s method. 






Amount Weight . Hydrocyanic Amygdalin 
ulbsuziace, of antiseptic. | of veadiutedl nites, ad forniedl decane 
grammes. hours. gramme. Per cent. 
(Control) ......... — 3 90 0 0063 10 °5 
Chloroform ...... 1 c.c. 3 90 0 -0060 10-0 
Tolwene............ dea 3 90 0 0061 9°8 
Pienol <....0..05.. 0-02 gramme 3 90 0 ‘0060 10 °0 

Action of Yeast on Glucosides. 
The results of the experiments already described indicate that the action of 
yeast on amygdalin is probably due to the presence in the yeast-cells of an 
enzyme of the type of emulsin, and it was considered desirable to ascertain 
whether or not the glucosidolytic constituent could be definitely identified 
with this enzyme. 
The identification of an enzyme is at: present a somewhat difficult problem, 
since it is as yet impossible to isolate bodies of this type in a pure state. 
Recourse must therefore be had to the investigation of the specific action 
of the ferment, and especially to the range of temperature over which it is 
active, the nature of the substances it decomposes, and the characters of the 
decomposition products. For this purpose the action of yeast on a number of 
elucosides other than amygdalin was examined. The principal results obtained. 
were as follows :— 
Salicin.—Yeast decomposes salicin in precisely the same manner as. 
emulsin, forming saligenin. The latter was isolated, and identified by means 
of its melting point (82°), and its characteristic colour reaction with ferric 
chloride. It might have been expected that some salicylic acid would have — 
been formed, due to the further action of the yeast on the saligenin,t+ but no. 
* ¢ Zeit. Biol.,’ 1900, vol. 40, p. 117. 
+ Compare Herzog, loc. cit. 
