Effect of chromium on the rate of carbon dioxide evolution from Saccharomyces cerevisiae

Abstract

The rate of carbon dioxide evolution by whole yeast cells was measured under conditions of both chromium starvation and availability. Preincubation experiments show that there is no evidence for the view that Saccharomyces cerevisiae can synthesize a biologically important form of chromium from simple chromium(III) salts. Chromium enters the yeast cell, possibly by way of the glucose transport system, and exerts a slight inhibitory effect on the fermentation rate but does not affect the rate of cell growth. Glucose tolerance factor fractions show a stimulatory effect in the yeast fermentation assay irrespective of whether the yeast is chromium depleted. The evidence shows that chromium is not an essential trace element for normal yeast metabolism and hence the activity of glucose tolerance factor preparations is unlikely to be due to a chromium complex as is commonly assumed. Some other as yet unidentified compound or compounds must be responsible for the observed increase in the rate of carbon dioxide evolution.