BACTERIA AND FERMENTATION 12/ 



Saccharomyces Pastorianus /. Oval or club-shaped cells, 

 bccurring in after-fermentation of wine, etc., and producing 

 a bitter taste, unpleasant odour, and turbidity. The spores 

 frequently occur in the air of breweries. 



S. Pastor. //. Elongated cells, possessing an invertose 

 ferment. They do not, like S, pastor /., produce disease in 

 beer. 



5. Pastor. III. Oval or elongated cells, producing turbid- 

 ity in beer. Grown on yeast-water gelatine, the colonies 

 show after sixteen days crenated hairy edges. 



Saccharomyces Apiculatus. Lemon-shaped cells. They 

 give rise to a feeble alcoholic fermentation, and produce two 

 kinds of spores — round and oval; they appear at the onset 

 of vinous fermentation, but give way later on to 5. cerevisim, 



Saccharomyces Mycoderma. Oval or elliptical cells, often 

 in branching chains. They form the so-called *' mould " 

 on fermented liquids, and develop on the surface without 

 exciting fermentation. When forced to grow submerged 

 they produce a little alcohol. 



Saccharomyces Exiguus. Conical cells, appearing in the 

 after-fermentation of beer. 



Saccharomyces Pyrtformis. Oval cells, converting sugary 

 solutions containing ginger into ginger-beer. 



Saccharomyces Illicisy Hansenii, et Aquifolii produce a 

 small percentage of alcohol. 



2. Acetous Fermentation, 



Cause, Mycoderma aceti ; medium, wine and other alcoholic liquids ; result, 

 the formation of vinegar. 



If alcohol be diluted with water, and the specific ferment 

 mixed with it and exposed to the air at 22° C, it is rapidly 

 converted into vinegar. The change is accompanied by the 

 absorption of oxygen, one atom of which combines with 

 two of hydrogen to form water, and a substance remains 



