Tyrosol and its glycosylated product salidroside are important ingredients in pharmaceuticals, nutraceuticals and cosmetics. Despite the ability of Saccharomyces cerevisiae to naturally synthesize tyrosol, high yield from de novo synthesis remains a challenge. Here, we used metabolic engineering strategies to construct S. cerevisiae strains for high-level production of tyrosol and salidroside from glucose. First, tyrosol production was unlocked from feedback inhibition. Then, transketolase and ribose-5-phosphate ketol-isomerase were overexpressed to balance the supply of precursors. Next, chorismate synthase and chorismate mutase were overexpressed to maximize the aromatic amino acid flux towards tyrosol synthesis. Finally, the competing pathway was knocked out to further direct the carbon flux into tyrosol synthesis. Through a combination of these interventions, tyrosol titres reached 702.30 ± 0.41 mg l⁻¹ in shake flasks, which were approximately 26-fold greater than that of the WT strain. RrU8GT33 from Rhodiola rosea was also applied to cells and maximized salidroside production from tyrosol in S. cerevisiae. Salidroside titres of 1575.45 ± 19.35 mg l⁻¹ were accomplished in shake flasks. Furthermore, titres of 9.90 ± 0.06 g l⁻¹ of tyrosol and 26.55 ± 0.43 g l⁻¹ of salidroside were achieved in 5 l bioreactors, both are the highest titres reported to date. The synergistic engineering strategies presented in this study could be further applied to increase the production of high value-added aromatic compounds derived from the aromatic amino acid biosynthesis pathway in S. cerevisiae.

中文翻译：

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酿酒酵母多模块工程高效生产酪醇和红景天苷

酪醇及其糖基化产物红景天苷是药物、保健品和化妆品中的重要成分。尽管酿酒酵母能够自然合成酪醇，但从头合成的高产率仍然是一个挑战。在这里，我们使用代谢工程策略来构建S. cerevisiae用于从葡萄糖中高水平生产酪醇和红景天苷的菌株。首先，酪醇的产生从反馈抑制中解脱出来。然后，转酮酶和核糖-5-磷酸酮醇异构酶被过表达以平衡前体的供应。接下来，分支酸合酶和分支酸变位酶被过表达以最大化芳香族氨基酸流向酪醇合成。最后，竞争途径被淘汰，以进一步引导碳通量进入酪醇合成。通过这些干预措施的组合，酪醇滴度在摇瓶中达到 702.30 ± 0.41 mg l ^-1，比 WT 菌株高约 26 倍。来自红景天的RrU8GT33也被应用于细胞并最大限度地从酿酒酵母中的酪醇产生红景天苷。在摇瓶中完成了 1575.45 ± 19.35 mg l ^{-1的红景天苷滴度。}此外，在 5 l 生物反应器中实现了 9.90 ± 0.06 g l ^-1的酪醇和 26.55 ± 0.43 g l ^-1的红景天苷滴度，两者都是迄今为止报道的最高滴度。本研究中提出的协同工程策略可进一步应用于增加酿酒酵母中芳香族氨基酸生物合成途径衍生的高附加值芳香族化合物的产量。