Cucurbitadienol is a key intermediate in the biosynthesis of cucurbitane-type compounds and serves as a precursor for mogrosides, cucurbitacins, and other valuable natural products of potential biological and food importance. However, microbial fermentation for cucurbitadienol production remains inefficient, limiting its potential for further industrial application. This study achieved the efficient synthesis of cucurbitadienol through a multimodular strategy. First, an N-degron tag was used to direct metabolic flux toward cucurbitadienol synthesis without compromising cell growth. Second, enzyme engineering strategies were employed to improve the utilization efficiency of intermediate metabolites. Finally, to increase precursor availability, the transcription factor UPC2–1 was introduced, which upregulated the expression of ERGs in the pre-squalene pathway. After eliminating nitrogen supplementation and optimizing fermentation conditions, cucurbitadienol accumulation in the 5 L bioreactor increased to 6.1 g/L, representing the highest titer reported to date. These findings provide a solid foundation for the industrial-scale production of cucurbitadienol and its derivatives.

中文翻译：

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通过酿酒酵母的模块化代谢工程和发酵优化实现葫芦二烯醇的过量生产


葫芦二烯酚是葫芦素类化合物生物合成的关键中间体，是罗汉果酯、葫芦素和其他具有潜在生物和食品重要性的有价值的天然产物的前体。然而，用于葫芦二烯醇生产的微生物发酵仍然效率低下，限制了其进一步工业应用的潜力。本研究通过多模块策略实现了葫芦二烯酚的高效合成。首先，使用 N-degron 标签将代谢通量引导至葫芦二烯酚合成，而不会影响细胞生长。其次，采用酶工程策略来提高中间代谢物的利用效率。最后，为了提高前体的可用性，引入了转录因子 UPC2-1，它上调了前角鲨烯通路中 ERG 的表达。在消除氮添加并优化发酵条件后，5 L 生物反应器中的葫芦二烯酚积累量增加到 6.1 g/L，这是迄今为止报道的最高滴度。这些发现为葫芦二烯酚及其衍生物的工业规模生产提供了坚实的基础。