Abstract:In order to analyze the mechanism of isoamyl alcohol synthetic metabolism in the fermentation process of Saccharomyces cerevisiae, this study used the native Saccharomyces cerevisiae LFE1225 as the experimental strain, with simulated wine fermentation. The isoamyl alcohol production rate, nitrogen source utilization, transcriptomics in the early, mid-log and end-log phases of the fermentation were compared and analyzed. The results showed that the synthesis and accumulation of isoamyl alcohol mainly occurred in the logarithmic phase; the synthesis rate of isoamyl alcohol in the initial stage of fermentation is the fastest, and it has a very significant positive correlation with ethanol synthesis rate, higher alcohol synthesis rate and sugar consumption rate. Saccharomyces cerevisiae LFE1225 utilized a large amount of YAN in the initial stage of fermentation and synthesized more leucine; after entering the logarithmic phase, leucine begins to be rapidly utilized. During the logarithmic period of fermentation, the expression of LEU2, BAT1/2, ILV5, LEU9, PDC6, THI3, ADH6 related to isoamyl alcohol metabolism of Saccharomyces cerevisiae LFE1225 were down-regulated, it was consistent with the change trend of isoamyl alcohol synthesis rate during this period; The 4 isoamyl alcohol metabolism-related genes, including BAP2, ILV2, PDC1, and SFA1 has the same expression trend with the 14 transcription factors including GAT1, ADR1, UPC2, GCN4, RPN4, RFX1, CUP2, RIM101, RLM1, SUM1, TYE7, GAL4, RME1 and USV1. And the transcription factors may be involved in the isoamyl alcohol metabolism regulation of Saccharomyces cerevisiae LFE1225. This study provides a reference for further understanding the metabolic mechanism of isoamyl alcohol in Saccharomyces cerevisiae, and provides a basis for the directed breeding of low/high isoamyl alcohol strains.