SACCHAROMYCES PASTORIANUS 

 SACCHAROMYCES PASTORIANUS. Hansen l 



237 



This is a species which is often encountered in the air in the vicin- 

 ity of breweries. It contributes a bitter, disagreeable taste and bad 

 odor to the beer. Thus it contributes to the diseases of beer and im- 

 pedes the clarification. It resembles very much Saccharomyces pas- 

 torianus described by Rees and Pasteur but is not capable of being 



Fig. 105. Ascs of S. 

 Pastorianus (after 

 Hansen) . 



Fig. 106. S. Pastorianus. Vegetative Cells from 

 Scum at 13-15C. (after Hansen). 



closely identified with this species. It forms in beer wort a sediment in 

 which the cells are more or less elongated, mixed with large and small 

 round or oval cells. (Fig. 3.) 



The temperature limits for budding in beer wort are: minimum 

 0.5 C., maximum 34 C. 



Temperatures for Ascospore Formation 

 At 31. 5 C. no formation of ascospores. 



29.5-30.5 first appearance of rudimentary ascospores in 30 hours. 



29 



27.5 



23.5 



18 



15 



10 

 8.5 

 7.0 

 3 -4 

 0.5 



27 

 24 

 26 

 35 

 50 

 89 



5 days 



6 " 

 14 " 



no formation of ascopores. 



1 Hansen, E. C. Recherches sur la physiologic et la morphologie des ferments 

 alcooliques. II. Les ascospores chez le genre Saccharomyces. III. Sur la 

 Torula de M. Pasteur. IV. Maladies provoques dans la biere par les ferments 

 alcooliques. Comp. Rend, du lab. de Carlsberg. Vol. 1, Book 2, 1883; Vol. 2, 

 Book 4, 1886; Cent. Bakt. Vol. 5, Book 2, 1909. 



