TORULA. 389 



Schionning submitted the Torula found by Claussen in 

 English beer to a close examination, during which he isolated 

 from different English beers some other species belonging to 

 the same group. He found that they fall naturally into two 

 <listinct groups. Schionning selected a typical representative 

 of each, described temporarily as Torula (A) and Torula (B), 

 3-nd gave a comprehensive description of both types. 



Both develop slowly in ordinary lager-beer wort. They 

 give a typical low fermentation, which, in the case of Torula 

 (B), lasts for six months at 20 C., whereas (A) ferments 

 somewhat more rapidly. 



Torula (A). The cells are elliptical, but at the same time 

 sausage-shaped and even mycelial forms occur together with 

 queer erratic shapes. The size is somewhat variable. Giant 

 cells with strongly refractive protoplasm and thick walls are also 

 found. The protoplasm of the ordinary cells is feebly refractive, 

 with indistinct vacuoles frequently containing a motile body. 



Torula (B). The cells look somewhat like Torula (A), 

 but are on the whole rather slimmer and more uniform, for 

 the most part sausage-shaped, but long mycelial cells also 

 occur. In older cultures a loose layer of mycelium consisting 

 of threads covers the true sedimentary yeast layer. 



In sterilised beer, which in the case of Torula (B) must be 

 mixed with a little saccharose or glucose, a slow propagation 

 takes place at 25 C. The beer at first thickens, and afterwards 

 gradually clarifies with the simultaneous formation of a some- 

 what coherent sediment. Its cells are, on the whole, larger 

 and more uniform, and the protoplasm is more refractive 

 than in the corresponding wort-cultures. If the development 

 has taken place in closed vessels the beer gives evidence of 

 -a high content of carbon dioxide when it is poured out, and 

 gives a fine head. By storage in flasks with access of air 

 both species form a feeble yeast ring and a film (like Saccharo- 

 mycetes) ; the cells are elongated. 



Torula (A) may sometimes occur with a fine, dry, and 

 greyish film like Mycoderma. The cells are then regular and 

 elliptical. Nothing is known as yet regarding the conditions 

 for such formation. It is probably derived from individual 

 differences in the cells. 



