Enhanced torularhodin production in Rhodosporidium toruloides A1-15 under salt stress: Insights from multi-omics analysis

The carotenoid-producing strain Rhodosporidium toruloides NP11 and its mutant strain A1-15 were cultivated under salt stress using chemostat cultivation. A multi-omics approach revealed distinct mechanisms between NP11 and A1-15 under stress conditions. Salt stress significantly reduced carotenoid production in NP11 but increased it in A1-15, with torularhodin being the predominant carotenoid in A1-15. NP11 exhibited enhanced lipid synthesis under salt stress, suggesting this as its primary adaptive response. In A1-15, reactive oxygen species (ROS) pressure upregulated the CRTI and CRTY genes, with a more pronounced upregulation of CRTI, likely contributing to increased torularhodin production. Additionally, upregulation of the COX7A gene in both strains may support energy demands and mitigate oxidative stress. Notably, this study is the first to mention and explore COX7A in research related to R. toruloides. [Display omitted] •Salt stress increased the accumulation of torularhodin as the predominant carotenoid in A1-15.•Upregulation of the CRTI gene drove torularhodin production in A1-15.•NP11 responded to salt stress by increasing lipid synthesis, including glycerolipids, long-chain fatty acids, and ergosterol.•The role of the COX7A gene in supporting energy needs and stress relief in R. toruloides was described for the first time.