Influence of Metabolic Regulators on the Astaxanthin Synthesis by <i>Xanthophyllomyces dendrorhous</i> and the Transcriptome Analysis

With the consumer pursuit for natural antioxidants, astaxanthin production by <i>Xanthophyllomyces dendrorhous</i> has garnered significant interest. However, the limited production levels hinder the industrial application of astaxanthin. This study systematically examined the effects of metabolic regulators including metal ions, surfactants, and vegetable oils on the astaxanthin synthesis by <i>X. dendrorhous</i> LX6. Transcriptome analysis found that genes of <i>crtYB</i> and <i>crtI</i> for astaxanthin synthesis, <i>adhp</i>, <i>acat</i>, and <i>fadD</i> for lipid metabolism, and <i>pla2g7</i> for cell membrane synthesis played major roles in the regulation of astaxanthin synthesis after the supplementation of metabolic regulators. Lipidomics analysis showed that the supplementation of Tween 80 or corn oil can regulate the fluidity of the cell membrane, affecting the astaxanthin production. Ultimately, <i>X. dendrorhous</i> LX6 synthesized 714.7 mg/L of astaxanthin using wheat straw hydrolysate as the substrate under the optimized conditions with the astaxanthin content of 18 mg/g, offering valuable insights for the industrial application of <i>X. dendrorhous</i>.