Construction and fermentation optimization of a hydroxyectoine-producing Escherichia coli strain.
- Author:
Hairui TONG
1
;
Hao ZHANG
1
;
Weiwei HUANG
1
;
Qi ZHANG
1
;
Yibin QIU
1
;
Sha LI
1
Author Information
- Publication Type:Journal Article
- Keywords: Escherichia coli; ectoine; fermentation engineering; hydroxyectoine
- MeSH: Escherichia coli/genetics*; Fermentation; Amino Acids, Diamino/biosynthesis*; Bioreactors/microbiology*; Metabolic Engineering/methods*; Chromohalobacter/genetics*; Plasmids/genetics*
- From: Chinese Journal of Biotechnology 2025;41(9):3448-3458
- CountryChina
- Language:Chinese
- Abstract: Hydroxyectoine, a vital compatible solute, is widely utilized in cosmetics, food, pharmaceutical industries, and biologics. However, the current microbial fermentation methods for hydroxyectoine production face challenges including insufficient precursor supply and low yields. Therefore, developing engineering microbial strains capable of efficiently synthesizing hydroxyectoine is of great significance. In this study, we first constructed a high-yield ectoine-producing strain ECT04 by multi-copy integration of the ectoine synthesis genes ectABC into the pseudogene loci of Escherichia coli MG1655(DE3), achieving an ectoine titer of 6.03 g/L. Subsequently, we employed plasmids with varying copy numbers to express ectD from Chromohalobacter salexigens to enable the conversion for hydroxyectoine production. We further investigated the effects of promoter, co-substrate ɑ-ketoglutarate, Fe2+ concentration, and dissolved oxygen on hydroxyectoine synthesis. Through fed-batch fermentation in a 7-L bioreactor, we significantly enhanced the hydroxyectoine production efficiency, attaining a final titer of 8.58 g/L and a productivity of 0.24 g/(L·h). This work successfully achieved the de novo synthesis of hydroxyectoine in E. coli, laying a foundation for the efficient bioproduction of this compound.
