REPRESSION OF GALACTOSE UTILIZATION BY GLUCOSE IN THE CITRATE-PRODUCING YEAST CANDIDA-GUILLIERMONDII

A strain of the yeast Candida guilliermondii has been shown to produce citric acid from galactose to a similar extent, and at a similar rate, as from glucose. At an initial concentration of 36 g/l of either glucose or galactose, citric acid production exceeds 13 g/l. When galactose and glucose are present in a mixture, however, galactose utilization is delayed until most of the glucose has been utilized, providing evidence for catabolite repression.