SCHIZOSACCHAROMYCES POMBE 199 



This indicated the possibility of two types of yeasts, a sporogeriic and 

 a non-sporogenic race. The light brown colonies are formed by a 

 mixture of the two types. 



Both types are encountered constantly in nature. They possess 

 different morphology and physiology. The sporogenic race is made 

 up of rectangular cells while, on the contrary, in the asporogenic type, 

 round cells predominate and are often situated in the shape of a 

 Sarcina. Finally the sporogenic race liquefies gelatin more rapidly 

 than the asporogenic. The sporogenic race shows a tendency to trans- 

 form into the asporogenic type when cultivated for a long time in 

 the laboratory. 



Schizosaccharomyces octosporus never produces a scum on beer wort 

 but simply a feeble ring. It ferments lactose, dextrose, levulose, 

 d-galactose, d-mannose, raffinose, dextrine and a-methylglucoside. It 

 may also cause a feeble fermentation of xylose (Lindner). It has no 

 action on saccharose which it does not ferment. From the biochemical 

 point of view, Schizosaccharomyces octosporus is distinguished from 

 Saccharomyces mellacei and Sch. Pombe in that it ferments d-galac- 

 tose and has no action on saccharose nor inuline. 



SCHIZOSACCHAROMYCES POMBE. Lindner 



Schizosaccharomyces Pombe was discovered by Saare and Zeidler in 

 African beer made from millet and described by Lindner l in 1893. 

 Its cells are much smaller than those of Schizosaccharomyces octo- 

 sporus, usually retangular, with rounded ends and about 7 /LI in length 

 and 4.5 /z broad. The cells resemble the Oidia of the 

 Endomyces very much or even giant bacilli. In old 

 media they tend to decrease in length and approach the 

 appearance of bacteria. 



They divide by transverse partition always in the 

 same way as Schizosaccharomyces octosporus (Fig. 75). 

 The transverse walls separate the cells into unequal Fig. 75. Vege- 



parts. Under certain conditions, as the absence of air, ^JX 6 Cells in 

 f Schizosaccha- 



tne cells elongate very much and may present many romyces Pombe 



cross walls without any separation taking place. Some- on Carrot 

 times one may observe the formation of lateral branches. 

 We have seen that Lepeschkin has been able to obtain on beer wort, 

 in the deposit, little floes having a characteristic mycelial formation 

 with cross walls and branchings. The cells of this yeast never include 

 glycogen. Growth demands at least a temperature of 15 C. 



1 Lindner, P. Schizosaccharomyces Pombe no. sp. ein neucr Garungserreger 

 Wochenschr. Brauerei. 1893. 



