Abstract: Complete synthetic minimal media for Zygosaccharomyces rouxii growth were designed for high temperature (40 ℃, HTS) and high salt stress (18% NaCl, HSS) in this study, and the difference in the nutritional requirements of Z. rouxii cells under long-term adverse environmental conditions was analyzed. The differences in the metabolism and gene expression of organic acids, amino acids and sugars during the period from the growth adaptation stage to the early logarithmic stage were highlighted between HSS and HTS conditions. The results showed that Z. rouxii cells exposed to HSS needed more exogenous amino acids, vitamin and amino acid supplementation alleviated HTS-induced damage in yeast cells. The adversity transcription gene MSN4 and the hypertonic regulatory protein gene HOG1 responded to high salt, while the heat shock regulatory protein gene HSF1 and the superoxide dismutase gene SOD1 responded to high temperature. In summary, different strategies for organic acid, amino acid and sugar metabolism were adopted by Z. rouxii in response to HSS and HTS. This study deepens the understanding of the mechanism of temperature tolerance in salt-tolerant Z. rouxii, which will contribute to the development of new brewing yeast cells with tolerance to both high salt and temperature.

Key words: Zygosaccharomyces rouxii; high salt stress; high temperature stress; complete synthetic medium; nutritional needs; metabolic differences; gene expression