Regulation involved in difference in nitrogen requirements of Saccharomyces cerevisiae wine yeasts in alcoholic fermentation

The objective of this work is to identify, in enological condition, differences in transcriptomic regulation that may explain the differences in strains fermentation properties. For this, we compared the global expression patterns of 8 Saccharomyces cerevisiae strains with different nitrogen requirement (L2868, 4CAR1, Fermiflor, Zymasil, MTF1782, 7013, K1M, EC1118). The transcriptome was analyzed on cells fermenting in a nitrogen limited medium containing 100mg.l-1 assimilable nitrogen (SM100) and harvested at stationary phase (45g/L of CO2 produced and corresponding to 6% ethanol). At this stage the strains exhibited differences in fermentation rates. Moreover, the transcriptome was shown to be rather stable at this stage since growth was stopped for all cells and nutrients have been depleted (Rossignol et al. 2003). Eight strains with different nitrogen requirement were analyzed (L2868, 4CAR1, Fermiflor, Zymasil, MTF1782, 7013, K1M, EC1118). This analysis includes two biological replicates for each strain.