초록
The specific growth rate of a Saccharomyces cerevisiae strain with glucose as limiting C-source was estimated from the measured heat flow produced by the cells. For the cultivation a standard 30l laboratory bioreactor was used, which was extended in such a way that heat balancing is possible. The feed rate was adjusted by a feedforward/feedback controller such that the specific growth rate was kept on the desired set-point value. On the basis of experimental investigations it was demonstrated that the specific growth rate can be controlled at a given set point value below the critical value to prevent the production of growth-inhibitory ethanol due to the Crabtree effect. With this control strategy high biomass concentrations of more than 110gl<SUP>-1</SUP> can be obtained.