Biotechnological Institute of Chinese Materia Medic, Jinan University, Guangzhou, 510632, China.
Microbial Pharmacology Laboratory, Shanghai University of Medicine and Health Sciences, Shanghai, 201318, China.
Metab Eng. 2020 May;59:44-52. doi: 10.1016/j.ymben.2020.01.007. Epub 2020 Jan 28.
Silymarin extracted from milk thistle seeds, is used for treating hepatic diseases. Silybin and isosilybin are its main components, and synthesized from coupling of taxifolin and coniferyl alcohol. Here, the biosynthetic pathways of taxifolin and coniferyl alcohol were reconstructed in Saccharomyces cerevisiae for the first time. To alleviate substantial burden caused by a great deal of genetic manipulation, expression of the enzymes (e.g. ZWF1, TYR1 and ARO8) playing multiple roles in the relevant biosynthetic pathways was selectively optimized. The strain YT1035 overexpressing seven heterologous enzymes and five native enzymes and the strain YC1053 overexpressing seven heterologous enzymes and four native enzymes, respectively produce 336.8 mg/L taxifolin and 201.1 mg/L coniferyl alcohol. Silybin and isosilybin are synthesized from taxifolin and coniferyl alcohol under catalysis of APX1t (the truncated milk thistle peroxidase), with a yield of 62.5%. This study demonstrates an approach for producing silybin and isosilybin from glucose for the first time.
水飞蓟素从水飞蓟种子中提取，用于治疗肝脏疾病。水飞蓟宾和水飞蓟宾是其主要成分，由杨梅素和松柏醇缩合而成。本研究首次在酿酒酵母中重建了杨梅素和松柏醇的生物合成途径。为了缓解大量遗传操作带来的巨大负担，选择性地优化了在相关生物合成途径中起多种作用的酶（如 ZWF1、TYR1 和 ARO8）的表达。分别过表达 7 种异源酶和 5 种内源酶的菌株 YT1035 和过表达 7 种异源酶和 4 种内源酶的菌株 YC1053 分别产生 336.8 mg/L 的杨梅素和 201.1 mg/L 的松柏醇。APX1t（截短的奶蓟过氧化物酶）催化下，水飞蓟宾和水飞蓟宾宾由杨梅素和松柏醇合成，产率为 62.5%。本研究首次从葡萄糖中生产水飞蓟宾和水飞蓟宾宾。
