Biosynthesis of 2,4-diacetylphloroglucinol from glucose using engineered Escherichia coli
- PDF / 1,355,210 Bytes
- 9 Pages / 595.276 x 790.866 pts Page_size
- 7 Downloads / 285 Views
(2020) 36:130
ORIGINAL PAPER
Biosynthesis of 2,4‑diacetylphloroglucinol from glucose using engineered Escherichia coli Wen Liu1 · Rubing Zhang1 · Mo Xian1 Received: 2 April 2020 / Accepted: 19 July 2020 © Springer Nature B.V. 2020
Abstract In order to produce 2,4-diacetylphloroglucinol (2,4-DAPG) in E. coli, the key synthases coding by phlACBD gene cluster from the strain Pseudomonas fluorescens CHA0 were overexpressed in E. coli BL21 (DE3). The marA, phlE and acc genes were also overexpressed to enhance 2,4-DAPG biosynthesis. Then the fermentation conditions were optimized to improve the concentration of 2,4-DAPG. The results showed that the recombinant E. coli could produce few 2,4-DAPG with only the phlACBD gene cluster. The synthetic ability of 2,4-DAPG could be increased by expressing the acc, marA and phlE genes in shake-flasks cultivation. The effects of phloroglucinol, initial pH, temperature and trace elements on 2,4-DAPG biosynthesis were also investigated. Based on the optimal fermentation conditions obtained from the shake-flasks cultivation, fed-batch fermentation of strain Z3 in a 5 L bioreactor was conducted to produce 2,4-DAPG. Finally, the concentration of 2,4-DAPG was 179 mg/L after induction for 36 h by fed-batch fermentation. To the best of our knowledge, this is the highest 2,4-DAPG production reported in E. coli. This work showed the potential application of engineered E. coli to get high production of target compounds. Keywords Escherichia coli · Fermentation · Phloroglucinol · 2,4-Diacetylphloroglucinol
Introduction The polyketide 2,4-diacetylphloroglucinol (2,4-DAPG) is a secondary metabolite produced by certain strains of Pseudomonas fluorescens with broad-spectrum antibiotic activity to bacteria, fungi, oomycetes and nematodes (Troppens et al. 2013). The biosynthesis of 2,4-DAPG is regulated by a gene cluster termed phlACBDEFGH (Almario et al. 2017; Bangera and Thomashow 1999; Sekar and Prabavathy 2014; Yang and Cao 2012). The enzymes directly involved in the formation of 2,4-DAPG are encoded by the genes phlACBD located in a single operon (Bangera and Thomashow 1999). The gene phlD encodes a type III polyketide synthase which is responsible for the conversion of three molecules of malonyl-CoA to phloroglucinol (PG) (Achkar et al. 2005). * Rubing Zhang [email protected] * Mo Xian [email protected] 1
CAS Key Laboratory of Bio‑Based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
Then the acetyltransferase encoded by phlACB catalyzes the acetylation of PG to monoacetylphloroglucinol (MAPG) and 2,4-DAPG (Yan et al. 2017). The phlE gene involves in the outflow of 2,4-DAPG and phlE mutant is more sensitive to high concentrations of 2,4-DAPG (Abbas et al. 2004). The phlF gene codes a repressor protein that regulates expression of phlACBD, and more 2,4-DAPG was produced by phlF disruption in P. fluorescens J2 than wild strain (Zhou et al. 2014). PhlG encoded by gene phlG can catalyze the conversion of DAPG
Data Loading...
