Metabolic engineering of Escherichia coli for production of hydroxytyrosol.
- Author:
Chunxiao LIU
1
;
Yuanyuan XIA
1
;
Lina QI
1
;
Haiquan YANG
1
;
Lei CHEN
1
;
Wei SHEN
1
;
Xianzhong CHEN
1
Author Information
- Publication Type:Journal Article
- Keywords: CRISPR-Cas9; Escherichia coli; hydroxylase; hydroxytyrosol; tyrosol
- MeSH: Escherichia coli/genetics*; Fermentation; Glucose; Metabolic Engineering; Phenylethyl Alcohol/analogs & derivatives*
- From: Chinese Journal of Biotechnology 2021;37(12):4243-4253
- CountryChina
- Language:Chinese
- Abstract: Hydroxytyrosol is an important fine chemical and is widely used in food and medicine as a natural antioxidant. Production of hydroxytyrosol through synthetic biology is of important significance. Here we cloned and functionally characterized a hydroxylase encoding gene HpaBC from Escherichia coli BL21, and both subunits of this enzyme can be successfully expressed to convert the tyrosol into hydroxytyrosol. A HpaBC gene integration expression cassette under the tac promoter was constructed, and integrated into the genome of a tyrosol hyper-producing E. coli YMG5A*R using CRISPR-Cas9 technology. Meanwhile, the pathway for production of acetic acid was deleted, resulting in a recombinant strain YMGRD1H1. Shake flask fermentation showed that strain YMGRD1H1 can directly use glucose to produce hydroxytyrosol, reaching a titer of 1.81 g/L, and nearly no by-products were detected. A titer of 2.95 g/L was achieved in a fed-batch fermentation conducted in a 5 L fermenter, which is the highest titer for the de novo synthesis of hydroxytyrosol from glucose reported to date. Production of hydroxytyrosol by engineered E. coli lays a foundation for further construction of hydroxytyrosol cell factories with industrial application potential, adding another example for microbial manufacturing of aromatic compounds.
