Yin Xinran, Zhang Yunliang, Wei Wenqian, Zhao Xingying, Xu Sha, Gao Song, Zhou Jingwen
Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China.
Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China.
J Agric Food Chem. 2025 Jan 8;73(1):718-726. doi: 10.1021/acs.jafc.4c09684. Epub 2024 Dec 18.
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 was introduced, which upregulated the expression of 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.
葫芦二烯醇是葫芦烷型化合物生物合成中的关键中间体，是罗汉果甜苷、葫芦素及其他具有潜在生物学和食品重要性的有价值天然产物的前体。然而，用于生产葫芦二烯醇的微生物发酵效率仍然低下，限制了其进一步工业化应用的潜力。本研究通过多模块策略实现了葫芦二烯醇的高效合成。首先，使用N-降解决定子标签引导代谢流朝着葫芦二烯醇合成方向，而不影响细胞生长。其次，采用酶工程策略提高中间代谢物的利用效率。最后，为了增加前体的可用性，引入了转录因子，其上调了角鲨烯前体途径中[具体基因]的表达。在消除氮补充并优化发酵条件后，5 L生物反应器中葫芦二烯醇的积累量增加到6.1 g/L，这是迄今为止报道的最高产量。这些发现为葫芦二烯醇及其衍生物的工业化规模生产提供了坚实的基础。
