Sailesh Malla and Ramesh Prasad Pandey contributed equally to this work.
Regiospecific modifications of naringenin for astragalin production in Escherichia coli
Article first published online: 22 APR 2013
Copyright © 2013 Wiley Periodicals, Inc.
Biotechnology and Bioengineering
Volume 110, Issue 9, pages 2525–2535, September 2013
How to Cite
Malla, S., Pandey, R. P., Kim, B.-G. and Sohng, J. K. (2013), Regiospecific modifications of naringenin for astragalin production in Escherichia coli. Biotechnol. Bioeng., 110: 2525–2535. doi: 10.1002/bit.24919
- Issue published online: 23 JUL 2013
- Article first published online: 22 APR 2013
- Accepted manuscript online: 8 APR 2013 07:11AM EST
- Manuscript Accepted: 22 MAR 2013
- Manuscript Revised: 20 MAR 2013
- Manuscript Received: 7 FEB 2013
- Converging Research Center Program from Ministry of Education, Science and Technology (National Research Foundation of Korea (NRF)). Grant Number: 2012K001387 to BG Kim and JK Sohng
- World Class University (WCU) program from NRF. Grant Number: R322012000102130 to BG Kim
- Next-Generation BioGreen 21 Program (SSAC), Rural Development Administration, Republic of Korea. Grant Number: PJ00948302 to JK Sohng
- E. coli;
- heterologous expression;
We report the production of astragalin (AST) from regiospecific modifications of naringenin (NRN) in Escherichia coli BL21(DE3). The exogenously supplied NRN was converted into dihydrokaempferol (DHK) and then kaempferol (KMF) in the presence of flavanone-3-hydroxylase (f3h) and flavonone synthase (fls1) from Arabidopsis thaliana, respectively. KMF was further modified to produce AST by 3-O-glucosylation utilizing the endogeneous UDP-glucose in presence of UGT78K1 from Glycine max. To increase the intracellular UDP-glucose concentration by channeling the carbon flux toward UDP-glucose at the branch point of glucose-6-phosphate (G6P), the chromosomal glucose phosphate isomerase (pgi) and D-glucose-6-phosphate dehydrogenase (zwf) were knocked-out in E. coli BL21(DE3). The two enzymes directly involved in the synthesis of UDP-glucose from G6P, phosphoglucomutase (nfa44530) from Nocardia farcinia and glucose-1-phosphate uridylyltransferase (galU) from E. coli K12 were overexpressed, which successfully diverted the carbon flow from glycolysis to the synthesis of UDP-glucose. Furthermore, to prevent the dissociation of UDP-glucose into UDP and glucose, the UDP-glucose hydrolase (ushA) was deleted. The E. coli ΔpgiΔzwfΔushA mutant harboring the UDP-glucose biosynthetic pathway and the aforementioned genes for the regiospecific glucosylation produced 109.3 mg/L (244 µM) of AST representing 48.8% conversion from 500 µM of NRN in 60 h without any supplementation of extracellular UDP-glucose. Biotechnol. Bioeng. 2013; 110:2525–2535. © 2013 Wiley Periodicals, Inc.