Astaxanthin has high utilization value in functional food because of its strong antioxidant capacity. However, the astaxanthin content of Phaffia rhodozyma is relatively low. Adaptive laboratory evolution is an excellent method to obtain high-yield strains. TiO2 is a good inducer of oxidative stress. In this study, different concentrations of TiO2 were used to domesticate P. rhodozyma. Results showed that the optimal astaxanthin-producing P. rhodozyma JMU-ALE105 was obtained under domestication with 1000 mg/L TiO2 concentration on the 105th day. After fermentation, the astaxanthin content reached 6.50 mg/g, which was 41.61% higher than that of the original strain. The ALE105 strain was fermented by batch and fed-batch, and the astaxanthin content reached 6.81 mg/g. Transcriptomics analysis showed that astaxanthin synthesis pathway, fatty acid, pyruvate and nitrogen metabolism pathway of ALE105 strain were significantly up-regulated. Based on the nitrogen metabolism pathway, the nitrogen source was adjusted by ammonium sulphate fed-batch fermentation, which increased the astaxanthin content reached 8.36 mg/g. This study provides technical basis and theoretical research for promoting industrialization of astaxanthin production of P. rhodozyma.

中文翻译：

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通过适应性实验室进化获得高产虾青素的法夫酵母/树状黄叶酵母的转录组学分析和补料分批调控

虾青素因其较强的抗氧化能力，在功能食品中具有很高的利用价值。然而，红法夫酵母的虾青素含量相对较低。适应性实验室进化是获得高产菌株的绝佳方法。TiO2 是氧化应激的良好诱导剂。在本研究中，使用不同浓度的TiO2 来驯化红酵母。结果表明，在1000 mg/L TiO2浓度下驯化第105天获得了最佳产虾青素酶JMU-ALE105。发酵后虾青素含量达到6.50 mg/g，比原菌株提高了41.61%。ALE105菌株通过分批和补料发酵，虾青素含量达到6.81 mg/g。转录组学分析表明，ALE105菌株的虾青素合成途径、脂肪酸、丙酮酸和氮代谢途径显着上调。基于氮代谢途径，通过硫酸铵补料发酵调整氮源，虾青素含量提高至8.36 mg/g。本研究为促进红酵母生产虾青素产业化提供技术基础和理论研究。