Induced Mutational Changes in Yeast 135 



maltose and simple dextrins of malt- wort. These forms may 

 be classified as species of S. ellipsoideus and S. cerevisiae, 

 respectively. 



(6) Biochemical investigation has shown that the active 

 enzyme invertase is found in intact cells, adapted to fermenta- 

 tion of sucrose and grown on a medium containing glucose, 

 whereas this enzyme is totally absent from original S. glohosus 

 cells. Homozygous adapted cells have twice as much invertase 

 as heterozygous ones. 



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