YEAST FROM PULQUE NO 2. 



257 



YEAST FROM PULQUE NO. 2. Guilliermond 1 



This yeast was isolated from the fermentation of Pulque, an al- 

 coholic drink prepared in Mexico. 

 In beer wort it develops as a very 

 abundant sediment with a whitish 

 yellow color. A wine fermentation is 

 produced in beer wort and a very 

 evident cloudiness. After a certain 

 time, it forms small floes with a 

 sparkling appearance which float in 

 the medium. Ring or scum forma- 

 tions have not been observed. The 

 sediment is made up of cells with 

 variable shapes, either oval, round, 

 or elongated, with pointed ends 



which resemble somewhat S. Lud- F ig. 121-A. - Yeast from Pulque No. 

 wigii. In general, budding is ac- 2. Sediment in Beer Wort after 15 

 complished at both ends of the cells. 



Often many buds are formed at the same time at each end, as in the 

 yeast-like structures of the Dematium. Even round cells budding like 

 Torula may also be observed. After a few days there is a produc- 

 tion of a deposit in the flask and a true mycelium which buds like 



Fig. 121-B. Copulated Ascospores 

 Changing into Ascs after having 

 Developed Cells in Yeast from 

 Pulque No. 2. 



Fig. 121-C. Copulation of Asco- 

 spores and Their Germination in 

 Yeast from Pulque No. 2 (after 

 Guilliermond). 



a Monilia. The maximum temperature for growth is situated near 

 40 C. and the optimum near 29-30 C. The spores are formed very 

 easily and abundantly on most solid media. They appear not only 

 in the yeast-like cells but also in cells in the mycelium. Generally, 

 they are to the number of four per cell. The maximum temperature 

 for sporulation is near 37 C., the optimum near 25 C. 



1 Guilliermond, A. Levaduras del Pulque. Boletin de la Direcci6n de 

 Estudios Biol6gicos, Mexico, 1917. 



