358 MICRO-ORGANISMS AND FERMENTATION, 



Saccharomyces Ilicis Gronlund 



which was found on the fruit of Ilex Aqui folium, is a bottom- 

 fermentation yeast, consisting mainly of spherical cells. The- 

 temperature limits of spore-formation are 38 and 8 C. The 

 spores have no vacuoles. In the films slightly-elongated cells- 

 are found. Streak cultures on gelatine have a floury, but 

 otherwise variable, appearance. This species, grown in wort^ 

 imparts a disagreeable, bitter taste. According to Schjerning, 

 it contains invertase, and induces alcoholic fermentation in. 

 solutions of saccharose, dextrose, and maltose. In ordinary 

 beer-wort it can yield about 2-8 per cent, of alcohol (by volume). 



Saccharomyces Aquifolii Gronlund 



was also found on the fruit of Ilex Aquifolium. It is a top- 

 fermentation yeast, and consists of large round cells. The 

 temperature limits for spore-formation are 31 and 8 C. ; the- 

 spores contain vacuoles. In the films, spherical and egg- 

 shaped cells alone occur. Streak cultures in gelatine vary in 

 appearance, some being glossy and some floury. This species 

 imparts to wort a disagreeable, sweet taste, with a bitter after- 

 taste. It inverts saccharose and induces alcoholic fermentation 

 in solutions of saccharose, dextrose, and maltose. In ordinary 

 beer-wort it can yield about 3-7 per cent, of alcohol (by volume). 



Saccharomyces pyriformis Marshall Ward 

 (see Ginger-beer Plant). 



Saccharomyces Vordermanni Went and Prinsen-Geerligs 



was discovered in Java as an essential factor in the manu- 

 facture of arrack. It is distinguished by its powerful action- 

 as an alcoholic ferment, and yields a fine distillate on account 

 of which it is made use of, in pure culture, in the manufacture- 

 of arrack. The cells are ellipsoidal, and form not more than 

 four spores. This species ferments dextrose, maltose, and 

 saccharose, and contains invertase. 



