Combined Proteomic and Metabolomic Analyses of Palmitoleic Acid-Associated Responses to Salt Stress in <i>Zygosaccharomyces rouxii</i>

Zygosaccharomyces rouxii is an important halotolerant yeast in high-salt fermentations, although the systems underlying its salt adaptation and nutritional regulation remain unknown. We characterized Z. rouxii CGMCC 3791 growing in YPD under control conditions or 120 g/L NaCl and assessed palmitoleic acid supplementation during salt stress. DIA-based LC-MS/MS proteomics and UPLC-Orbitrap metabolomics were combined with KEGG enrichment and pathway mapping. PCA effectively differentiated the three groups across both omics layers, demonstrating that palmitoleic acid induces a unique reprogramming beyond the salt-only response. The enrichment analysis revealed the coordinated regulation of amino acid metabolism, glutathione-associated redox activities, ABC transporters, oxidative phosphorylation, and cofactor pathways, including pantothenate and CoA biosynthesis. Integrated mapping demonstrated increased purine-related intermediates (FAICAR, IMP, ADP, and inosine) and lipid-related remodeling. Overall, these results suggest that palmitoleic acid may contribute to salt-stress adaptation in Z. rouxii by modulating energy and nucleotide turnover, while helping maintain redox balance and metabolic flexibility.