葫芦二烯醇的异源高效合成研究

Study of heterologous efficient synthesis of cucurbitadienol

葫芦二烯醇具有抑制炎症和抗癌活性,同时为罗汉果甜苷和葫芦素等重要中药有效成分生物合成途径中的基本前体。为获得高效生产葫芦二烯醇的酿酒酵母细胞工厂,该研究首先从罗汉果中克隆到葫芦二烯醇合酶(CBS)基因,通过在三萜化合物底盘菌WD-2091中异源表达和发酵后,产物经过GC-MS鉴定获得产量为27.44 mg·L^(-1)工程菌。再进一步调控工程菌中葫芦二烯醇合酶基因表达,最终成功获得葫芦二烯醇提高202.07%,产量为82.89 mg·L^(-1),高密度发酵达到1 724.10 mg·L^(-1)的酿酒酵母细胞工厂313-SL-CB。该研究为推动葫芦烷型四环三萜生物合成途径解析及高效细胞工厂创建提供了基础。

Cucurbitadienol has anti-inflammation,anti-cancer activities,and acts as a precursor of traditional Chinese medicine active ingredients mogroside and cucurbitacine. For construction of a Sacchromyces cerevisiae cell factory for production of cucurbitadienol,we firstly cloned a cucurbitadienol synthase（ CBS） gene from Siraitia grosvenorii. Then,through heterologous expression of CBS in the triterpenoid chassis strain WD-2091,the engineered strain could produced 27. 44 mg·L^（-1）cucurbitadienol,which was determined by GC-MS. Further regulation of CBS expression led to cucurbitadienol＇s titer increasing by 202. 07% and reaching 82. 89 mg·L^（-1）in the shake flask fermentation and 1 724. 10 mg·L^（-1）in the high cell density fermentation. Our research promotes the cucurbitane-type tetracyclic triterpenoids synthesis pathway analysis progress and provides the basis for further obtaining cell factories for production of cucurbitadienol tetracyclic triterpenoids.