PHYSIOLOGICAL CONSEQUENCES OF POLYPLOIDY IN YEASTS - II. Growth and Yield Characteristics of the Diploid and the Autotetraploid Brewery Yeasts

Abstract

1. The  improvement  in  the  fermentative  ability  on  duplication  of  the  chromosome  complement  of  a  diploid  brewery  yeast  necessitated  a  detailed  study  of  the  yield  and  growth  characteristics  of  the  diploid  and  the  autotetraploid  with  a  view  to  possible  exploitation  in  the  food  yeast  industry.
2. Experiments  under  a  variety  of  physiological  conditions  show  that  the  criterion  employed  for  assessment  influences  the  interpretation  or  the  data  obtained.  Under  conditions  of  vigorous  aeration,  the  four  chromosome  strain  is  found  to  give  higher  yield  of  yeast  than  the  diploid.  It  has  been  demonstrated  that  the  tetraploid  is  more  sensitive  to  carbon  dioxide  tension  than  the  diploid.
3. The  implications  of  the  results,  both  theoretical  and  technical,  are  discussed.  4.  That  chromosomal  duplication  decreases  the  moisture  content  of  the  material  has  also  been  recorded.