
1905.| On the Probable Existence of Emulsin in Yeast. 573 — 
table that hydrocyanic acid exerts very little, if any, inhibiting action on the 
glucosidolytic activity of yeast juice, even in comparatively strong solutions. 
On the contrary Buchner has shown* that this acid lessens the activity of 
the zymase in yeast juice. | 
2 Volume of . ; 
eee oe. 1 per cent. solution hae ete Amygdalin 
ioe y J of hydrocyanic me decomposed. 
used. added. Ee Pe action proceeded. 
gramme. c.c c.c. hours. Per cent. 
1 5 ay | 36 12 
1 5 5 36 11°53 
1 5 10 36 12 
i 5 20 36 11 


It is well known that the activity of the zymase of yeast juice decreases 
when the juice is kept,f and this is generally ascribed to the action of the 
proteolytic enzyme (endotryptase) first detected in yeast by Hahn and 
Geret.{ It was consequently considered advisable to ascertain whether the 
glucosidolytic action of yeast juice similarly diminishes on keeping. The 
juice was kept at the atmospheric temperature and its activity towards 
amyedalin tried at intervals. 
Time required to initiate 

Juice. Time the decomposition of 
of standing. dali 
| amygdalin. 
hours hours 
Specimen No. 1...... 24, 22 
re Now Tiatiscs 47 23 
bs NOs 1: occ. 120 26 
i Noo: eee 24 40 
MeileNoyo ee. 120 56 
It is evident from these results that the glucosidolytic activity undergoes 
slight diminution when the yeast juice is kept, but this diminution is in 
no way comparable with that which the activity of the zymase undergoes 
under the same conditions. For purposes of comparison, some experiments 
were made to ascertain whether the commoner proteolytic enzymes interfered 
to any extent with the action of the emulsin of almonds. For this purpose 
1 gramme of Merck’s emulsin was thoroughly mixed with 100 c.c. of water, 
* ‘Berichte,’ 1898, vol. 31, p. 2672. 
+ Albert and Buchner, ‘ Berichte,’ 1900, vol. 33, p. 971. 
t ‘ Berichte,’ 1898, vol. 31, p. 202. 
