Figure 2.

S. kudriavzevii has increased expression of the cold stress gene marker NSR1 at low temperature. Gene expression measured by qPCR technique after S. cerevisiae (T73) or S. kudriavzevii (IFO1802) cells were transferred to 12 (light grey) or 28°C (dark grey) synthetic grape must. Samples were taken 2 hours after the inoculation (A), when the OD₆₀₀ reached the double of the initial OD₆₀₀ (B), in the middle of exponential phase (C), and at the start (D) and at the end (E) of the stationary phase (sugar exhaustion). Average of biological triplicates was calculated and standard deviations were lower than 20%. Gene expression levels are shown as the changes in the concentration of the studied gene compare to the control sample and normalized with the concentration of the housekeeping ACT1 gene. Gene expression differences between 12 a 28°C were statistically significant, except in the case of time point A for S. kudriavzevii.