SACCHAROMYCES. 363 



is 32 C., optimum 26 to 29 C. The spores (usually two in 

 each cell) are round. They are easily produced both in liquid 

 and on solid substrata, and especially well in tartaric acid 

 solution containing potassium nitrate. The fungus can supply 

 its demand for carbon from saccharose, glucose, and mannite,. 

 but not from maltose, lactose, galactose, inulin, and melam- 

 pyrite. It is capable of fermenting a saccharose solution, 

 containing 50 per cent, of sugar. During* fermentation an 

 acid is produced which at a later stage is used up. 



According to Artari, it can satisfy its requirements for 

 nitrogen with ammonium sulphate. When the species is 

 cultivated in a dextrose solution containing from 5 to 8 per 

 cent, of ammonium sulphate, transverse walls make their 

 appearance between the mother and daughter cells, as is the 

 case with S. Ludwigii. In such a solution only spherical cells- 

 occur. The addition of potassium nitrate brings about an 

 alteration to pear-shaped cells. 



Saccharomyces Bailii Lindner 



was isolated from Jopen beer-wort which had a primary con- 

 centration of 53 to 54 Balling. The cells are large, thick- 

 walled, and elongated, and assume irregular shapes in old 

 cultures (like Amoeba). The spores are strongly refractive. 

 There is no film-formation. It ferments dextrose and sac- 

 charose, but not d-galactose and d-mannose. It gives a feeble 

 fermentation in wort, and in old cultures the wort has a slight 

 perfumed odour. It forms the main constituent of yeast in 

 Jopen beer samples, and doubtless plays a part in the pre- 

 paration of Danzig Jopen beer. 



Saccharomyces hyalosporus Lindner 



forms a thin film on wort, and produces no fermentation in 

 the different kinds of sugar. The spores are round, and 

 resemble glass beads carrying a lustrous granule in the centre. 

 It forms spores in the film. The cells are oval, and sometimes 

 rather elongated. They are often linked together in chains. 



It was discovered by Lindner in a sample of beer from a 

 propagating apparatus. 



