Modulating heterologous pathways and optimizing fermentation conditions for biosynthesis of kaempferol and astragalin from naringenin in Escherichia coli

作者：Pei, Jianjun; Chen, Anna; Dong, Ping; Shi, Xuejia; Zhao, Linguo^*; Cao, Fuliang; Tang, Feng

来源：Journal of Industrial Microbiology and Biotechnology, 2019, 46(2): 171-186.

DOI：10.1007/s10295-018-02134-6

• Kaempferol
• Astragalin
• Metabolic engineering
• Flavonoid biosynthesis
• Escherichia coli

Kaempferol and astragalin are used as standards to assess the quality of Ginkgo biloba extract and Radix astragali, respectively, and possess numerous biological properties. In this study, we constructed a recombinant strain with a highly efficient biosynthetic pathway of kaempferol by screening key enzyme genes, designing a synthetic fusion enzyme and increasing the gene copy number. By optimizing conversion and fed-batch fermentation conditions, maximal kaempferol production reached 1184.2 +/- 16.5mg/L, which represents the highest yield of kaempferol from naringenin reported to date. Based on this result, glycosyltransferase (AtUGT78D2) and an efficient UDP-glucose synthesis pathway were introduced into the recombinant strain to produce astragalin, resulting in maximal astragalin production at 1738.5 +/- 24.8mg/L without kaempferol accumulation. The efficient synthesis pathway described in this study for kaempferol and astragalin biosynthesis can be widely used for flavonoid biosynthesis in Escherichia coli.

• 出版日期2019-2
• 单位南京林业大学; 国际竹藤中心