NADH-dependent culture fluorescence is increasingly used for the characterization of the biological state of the cells, when their environment changes. For better interpretation of the signal variations time resolved measurements are necessary. Saccharomyces cerevisiae H620 strain was cultivated on synthetic medium in continuous operation and time resolved response to variation of the dissolved oxygen and glucose concentrations were monitored by measuring the concentrations of cell mass, glucose, ethanol, acetaldehyde, glycogen, trehalose, mannan, lipids, dissolved oxygen, O 2 and CO 2 in off-gas as well as the NADH-dependent culture fluorescence. The time resolved ethanol concentration and fluorescence intensity changes under different cultivation conditions are used to discuss the cell responses to their environmental change.
