294 NON-SACCHAROMYCETES OR DOUBTFUL YEASTS 



Torula No. 2. This yeast differs from the preceding by its larger 

 cells, from 3 to 8 ju in diameter, and granular protoplasm. 



Torula No. 3. Morphologically similar to the pre- 

 ceding yeast, this yeast produces 7 to 8 per cent of 

 alcohol by volume in beer wort. It forms a foam and 



Fig. 139. sets free much carbon dioxide. No invertase is pro- 



Torula 6 of , , 



Hansen. duced - 



Growth of Torula No. 4. It possesses cells from 2 to 6 ju in 



Sediment in diameter. It inverts saccharose and gives a little more 

 Beer Wort than 1 per cent of alcohol by volume in beer wort with 

 Da'y at 25 the formation of much foam. It 

 C. (after does not ferment maltose. 



Torula No. 5. This yeast 

 resembles Torula No. 1 in the shape and dimen- 

 sions of its cells. It forms a homogeneous dull _. 



. Fig. 140. Torula 7 of 

 gray scum on beer wort at the temperature of Hansen. Growth of 



the laboratory and in other liquids containing gells J Sediment in 



, J f . , . T , . Beer Wort after One 



10 per cent of alcohol. In solutions of sac- Day at 25 C. (after 



charose, it forms a thin scum. It inverts sac- Hansen). 

 charoee but produces only traces of alcohol in sugar solutions. 



Torula No. 6. It possesses spherical or oval cells. The limits of 

 temperature for budding are 4-6 C. and 36-37 C. (Fig. 139.) This 



species causes an apparent fermentation 

 in beer wort and yields 1.3 per cent of 

 alcohol. It produces no fermentation in 

 maltose solutions. It inverts saccharose 

 and forms 5.1 to 6.2 per cent of alcohol 

 by volume in yeast water with added 



"Ooo^cfccpV^- sugars at 25 C. after 15 days; after two 



Fig. 141. Torula 7 of Hansen months, seven per cent of alcohol is 

 on Scum at the End of 10 formed. In solutions of dextrose, it pro- 

 Months in Wort (after Han- , n . K > > i , 

 gen ) duces 6.6 to 8.5 per cent of alcohol by 



volume. 



Torula No. 7. Found in the soil under vines, this species is 

 made up of ordinary oval cells larger than those in the preceding 

 yeast. (Fig. 140.) The oval cells are irregularly formed. (Fig. 141.) 

 The temperature limits for budding are 0.5 and 38-39 C. This species 

 produces 1 per cent of alcohol by volume in beer wort. It does not 

 ferment maltose or invert saccharose. In yeast water with dex- 

 trose added (10 or 15 per cent) it yields at the end of 15 days, 4.5 per 

 cent of alcohol by volume. After 28 days, it produces 4.8 to 5.3 per 

 cent of alcohol. Hansen thinks that this species like the preceding 

 participates in the fermentation of wine and cider. 



