Differential analysis of ergosterol function in response to high salt and sugar stress in Zygosaccharomyces rouxii

Abstract

Zygosaccharomyces rouxii is an osmotolerant and halotolerant yeast that can participate in fermentation. To understand the mechanisms of salt and sugar tolerance, the transcription levels of Z. rouxii M 2013310 under 180 g/L NaCl stress and 600 g/L glucose stress were measured. The transcriptome analysis showed that 2227 differentially expressed genes (DEGs) were identified under 180 g/L NaCl stress, 1530 DEGs were identified under 600 g/L glucose stress, and 1278 DEGs were identified under both stress conditions. Then, KEGG enrichment analyses of these genes indicated that 53.3% of the upregulated genes were involved in the ergosterol synthesis pathway. Subsequently, quantitative PCR was used to verify the results, which showed that the genes of the ergosterol synthesis pathway were significantly upregulated under 180 g/L NaCl stress. Finally, further quantitative testing of ergosterol and spotting assays revealed that Z. rouxii M 2013310 increased the amount of ergosterol in response to high salt stress. These results highlighted the functional differences in ergosterol under sugar stress and salt stress, which contributes to our understanding of the tolerance mechanisms of salt and sugar in Z. rouxii.

High Glucose Is a Stimulation Signal of the Salt–Tolerant Yeast Zygosaccharomyces rouxii on Thermoadaptive Growth

“…In particular, Z. rouxii can grow and survive under pressure caused by high concentrations of non–ionic (sugars and polyols) and ionic (mainly Na + cations) solutes [ 7 , 8 ]. When Z. rouxii cells are stressed by high glucose and high salt, they activate stress signaling pathways, such as the HOG pathway, the calcineurin/Crz1 pathway, and the Ras–cAMP pathway [ 5 , 7 , 9 ]; produce and accumulate metabolically compatible osmotic and protective agents, such as trehalose, xylitol, and glycerol [ 10 , 11 ]; and regulate the structural characteristics of the cell wall and plasma membrane, as well as adjusting the transport system [ 12 , 13 ]. All of these improve the tolerance of Z. rouxii cells and determine the success of fermentation on high–osmotic food substrates [ 14 ].…”