1993 Volume 39 Issue 4 Pages 389-394
A sucrose-adapted inoculum of Saccharomyces cerevisiae growing in a batch fermenter in a sucrose medium was dosed with a high concentration of the enzyme invertase (β-D-fructosidase) during the mid-exponential phase of growth. The culture then underwent a short lag of about 20min before dramatically decreasing its growth rate. The sugar analysis profiles showed that, during the lag phase, all the sucrose was hydrolyzed to glucose and fructose. The specific growth rate decreased from 0.50h-1 when growing on sucrose (before addition of invertase) to 0.44h-1 on the resulting mixture of glucose and fructose. These results help in explaining the mechanism of utilization of sucrose by actively growing yeast cells in a batch culture and suggest a direct uptake of sucrose molecules into yeast cells.
