1905. | Studies on Enzyme Action. 603 
The results which have been obtained are summarised in the following 
table. The sign + is used to indicate that a particular sugar is fermented, 
the sign 0 to indicate that it is not fermented. Inasmuch as a biose must be 
hydrolysed before it can be fermented, the ability or the reverse of a yeast to 
ferment a given biose sugar denotes the presence or absence of the particular 
enzyme which will hydrolyse the biose; the signs in the three columns 
headed maltose, sucrose and lactose respectively may therefore be read as 
implying the occurrence or abseuce, as the case may be, of fermentation, as 
well as the occurrence or absence of a particular enzyme. Although inability 
to hydrolyse a biose when it has diffused into the yeast cell would seem to be 
as severe a test of the absence of the enzyme from the cell contents as it is 
possible to apply, it has been thought desirable in several cases to grow the 
yeast in quantity and to prepare an extract from the dried material ; in all 
such cases the result has been that no enzyme has been proved to be present 
the absence of which was indicated by the behaviour of the yeast towards 
the bioses. 


: ? i = = us = | Sa 
| | | | 
Yeast. | Glucose | Fructose 
| 
Mannose | Galactose Maltose | Sucrose | Lactose 
| (maltase).|(invertase).| (lactase). 



Yeasts containing maltase and invertase. 








Cerevisie ............ + + | + | t + + 0 
Carlsberg ............ + + | ae + + + 0 
Pombe 02... ..5.4. 003 + + + | O + + 0 
Thermantitonum ... + + | + + + + 0 
Yeasts containing invertase alone. 
Marxianus ......... | + | + + + 0 oa | 0 
AGUS .n.. ese | + = ana! + 0 + | 0 
| UG WHET <2 6.5..0. 00 + | + + 0 0 + | 0 
SPACUEAUS) .occseceess | + + + 0 0 + O 
Anomalus .........06 + | + + 0 0 + 0 
Yeasts containing maltase alone. 
Octosporus ......... ae | oe + Oly + 1) | 0) 
Capsularis ............ + | + + + | + 0 | 0 
GIOGKET oh 5.050 seein’ + + + 0 | + 0 0 
Yeasts containing lactase and invertase. 
FETT, wsiennnevseess | + ee | = pry + | uy a 
ike os + + | py fe) 0 | + + 
FEAR SET (sce deleoesinee + + + | 0 0) + + 
Adametz ............ + + + 0 @) + + 
BO ech ehaseey vost + + + + 0 + + 
Yeasts without sucroclastic enzymes. 
Apiculatus............ + + + 0 0 0 0 
ns Schweiz + | + + 0 0 8) 0 
Mali Duclauxi* + + + ? O O 0 
ne hss cat 
* TI have not worked with this yeast. 

