鼠李糖
槲皮素
化学
大肠杆菌
纤维二糖
生物化学
拟南芥
类黄酮
酶
多糖
基因
纤维素酶
突变体
抗氧化剂
作者
Na Gu,Cong Qiu,Linguo Zhao,Lihu Zhang,Jianjun Pei
标识
DOI:10.1021/acs.jafc.0c03689
摘要
UDP-rhamnose is the main type of sugar donor and endows flavonoids with special activity, selectivity, and pharmacological properties by glycosylation. In this study, several UDP-glucose synthesis pathways and UDP-rhamnose synthases were screened to develop an efficient UDP-rhamnose biosynthesis pathway in Escherichia coli. Maximal UDP-rhamnose production reached 82.2 mg/L in the recombinant strain by introducing the cellobiose phosphorolysis pathway and Arabidopsis thaliana UDP-rhamnose synthase (AtRHM). Quercitrin production of 3522 mg/L was achieved in the recombinant strain by coupling the UDP-rhamnose generation system with A. thaliana rhamnosyltransferase (AtUGT78D1) to recycle UDP-rhamnose. To further increase UDP-rhamnose supply, an NADPH-independent fusion enzyme was constructed, the UTP supply was improved, and NADPH regenerators were overexpressed in vivo. Finally, by optimizing the bioconversion conditions, the highest quercitrin production reached 7627 mg/L with the average productivity of 141 mg/(L h), which is the highest yield of quercitrin and efficiency of UDP-rhamnose supply reported to date in E. coli. Therefore, the method described herein for the regeneration of UDP-rhamnose from cellobiose may be widely used for the rhamnosylation of flavonoids and other bioactive substances.
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