Comparative Transcriptome Analysis of Industrial and Laboratory <i>Saccharomyces cerevisiae</i> Strains after Sequential Stresses

While the transcriptional responses of yeast cells to a variety of individual stress conditions have been extensively studied, their responses to sequential stress conditions are less well understood. In this study, we present a comparative analysis of the transcriptome of an industrial strain and a laboratory strain exposed to different sequential stresses to establish a common response profile and also to identify genes whose expression is strain-dependent. Both strains induce pathways related to oxidative stress and osmotic stress response including those involved in glycerol synthesis, glutathione metabolism, and NADPH regeneration. Other genes that may also play an important role in this response include the transcription factor <i>ADR1</i>, <i>SYM1</i>, and most of the heat shock proteins. Induction of genes related to autophagy of mitochondria occurred only in the laboratory strain while possible stress tolerance factors, such as additional genes involved in glutathione production and detoxification, were uniformly enhanced only in the industrial strain. The analysis of the stress response to sequential stresses of two different strains allowed more precise identification of the response of yeast to complex environments. Identification of genes uniquely induced in the industrial strain can also be used to develop strategies to optimize various fermentation processes.