SACCHAROMYCES MANGINI 



261 



<o> * 



Fig. 121-F. Saccharomyces paradoxus. 



a and 6, Ascs ; c, d, e, and /, Fusion of Cells and Forma- 

 tion of Promycelium; m, g, I, yeast Cells Derived 

 from Budding of Copulated Cells Formed by the 

 Promycelium ; i, Promycelium Transforming Directly 

 into an Asc (after Batschinskaia) . 



difficult. From 1 to 8 ascospores are formed in each asc, generally 4. 

 Germination is preceded by a fusion of the ascospores. This is ac- 

 complished between two ascospores but usually one may see from one 

 to three or a greater number fusing. The cells which result from this 

 fusion finally elongate and take 

 on various shapes, giving a sort 

 of promycelium. In this pro- 

 mycelium, there are formed 

 many generations of buds. The 

 cells which result from the bud- 

 ding fuse two by two, and these 

 are the cells, which by budding, 

 produce vegetative cells. 

 Streaks on gelatin give colonies 

 which are white, small and 

 striking. On must agar, the 

 yeast develops under the form 

 of a brilliant coating, viscous 

 and light yellow. The giant 

 colonies on must agar have the 

 same color as the colonies on 

 streak cultures. Bouillon cultures with beer wort added give no scum 

 but a brown sediment and a cloudiness. This yeast ferments glucose, 

 levulose, saccharose and galactose. A cytological study of the yeast 

 seems advisable in order to interpret the cell structure during the 

 different stages of growth. 



SACCHAROMYCES MANGINI. Guilliermond l 



This yeast was isolated from fermenting wine Bili made at Conakry 

 and was found along with a species named Zygosaccharomyces Cheva- 

 lieri. This wine is a drink prepared from tubercles of the Osbeckia 

 grandiflora. 



On beer wort at 25 C., S. Mangini forms an abundant white sedi- 

 ment. When -examined microscopically after 24 hours the sediment 

 seems to be made up of oval or round cells resembling somewhat 

 those of S. cllipsoideus. This yeast then also belongs to the ellipsoi- 

 deus type. The cells are isolated and sometimes united into budding 

 colonies of from 2-4 cells. They are smaller than the cells of S. 

 Chevalieri. The average dimensions are about 4.4 ju, wide and 6.75 n 

 in length. The cells keep the same form after 15 days. 



1 Guilliermond, A. Monographic des levures rapporte*es d'Afrique occidentale 

 par la Mission Chevalier. Annales des Sciences Naturelles Botaniques, 19, 

 1914. 



