124 K. V. KossiKov 



one-third of raffinose. Therefore, they acquired the abihty to 

 produce the active enzyme p-D-fructosidase. 



Group 2. These forms ferment not only monosaccharides, but 

 also maltose. Therefore, they acquired the ability to produce 

 the active enzyme a-glucosidase. 



Group 3. These forms ferment maltose and sucrose but fail 

 to ferment raffinose. As has already been mentioned, in this 

 case sucrose is hydrolysed by the enzyme maltase. These 

 forms do not differ from the preceding ones in the type of 

 enzyme produced. However, since the ability to produce the 

 active enzyme maltase was developed in this case on the 

 medium containing sucrose, these forms readily ferment 

 sucrose already within the first 10 days, while the cultures of 

 the preceding group failed to ferment sucrose within the 

 same period of time. 



Group 4. These forms ferment not only monosaccharides, but 

 also sucrose, maltose and one-third of raffinose. They were 

 obtained in two stages: first a culture oiS. glohosus 74/349 was 

 adapted to fermentation of sucrose ; then this was adapted to 

 fermentation of maltose on a medium containing maltose. 



The forms obtained from S. paradoxus are divided into 2 

 groups, based on differences in fermentative properties: 



Group 1. In contradistinction to S. paradoxus, these forms 

 ferment maltose. Therefore, they acquired the ability to 

 produce the active enzyme a-glucosidase. 



Group 2. After long cultivation on beer-wort, cultures pre- 

 viously adapted to fermentation of maltose (group 1) became 

 adapted to fermentation of simple dextrins of malt-wort. 



The above-mentioned altered forms, obtained from S. 

 glohosus and S, paradoxus, were studied in comparable condi- 

 tions, with the aim of estimating their sugar-fermenting 

 capacity and the depth at which beer- wort is fermented. In 

 parallel experiments, we also studied in comparable conditions 

 cultures of original forms of S. glohosus, S. paradoxus, S. 

 chodati, S. ellipsoideus and S. cerevisiae. The last three species 

 were used for comparison with the altered forms. 



