Examination of the transcriptional specificity of an enological yeast. A pilot experiment on the chromosome-III right arm.

The adaptation of yeasts to industrial environments is thought to be largely dependent on gene-expression specificity. To assess the transcriptional specificity of an enological strain, we performed a pilot experiment and examined the transcript level of 99 ORFs of the chromosome-III right arm with two strains, an enological-derived strain and a laboratory strain, grown under three different physiological conditions: respiration, standard alcoholic fermentation and enological alcoholic fermentation. The use of 99 single ORF-derived probes led to the detection of 49 transcripts, most of which were present at low levels and were not regulated. Ethanol respiration induced transcripts, in a similar manner with both strains. While standard alcoholic fermentation led to only minor regulations, the enological fermentation conditions triggered the expression of different genes. In addition, a specific transcriptional response to these conditions was observed with the enological-derived strain. The known or predicted functions of several genes induced under enological conditions is related to either alcoholic fermentation or stress, suggesting that their specific induction could reflect adaptation of the strain to the enological environment. Our data suggest that systematic transcriptional studies are an effective way to assess the molecular basis of yeast adaptation to industrial environments.