Enhancing Synthesis Efficiency in Microbial 1,5-Pentanediol Production Through Transcriptomics-Informed Metabolic...

Area of Science:

• Metabolic Engineering
• Synthetic Biology
• Biotechnology

Background:

• Microbial production of 1,5-pentanediol (1,5-PDO), a valuable platform chemical, is hindered by low fermentation yields and poorly understood metabolic pathways.
• Identifying genetic targets is crucial for improving 1,5-PDO biosynthesis efficiency in engineered microorganisms.

Purpose of the Study:

• To systematically identify and validate novel genetic targets for enhancing 1,5-pentanediol (1,5-PDO) production in engineered *Escherichia coli* using comparative transcriptomics.
• To engineer an optimized *E. coli* strain for improved 1,5-PDO titers and yields.

Main Methods:

• Comparative transcriptomics was performed on 1,5-PDO producing *E. coli* versus the parental strain at different growth phases.
• Candidate genes were validated via overexpression or CRISPR interference (CRISPRi).
• Genetic modifications, including chromosomal integration and gene deletion, were implemented to create an optimized strain.

Main Results:

• Transcriptomic analysis revealed 1384 differentially expressed genes, leading to the selection of 20 candidate metabolic genes.
• Overexpression of *fecA* and deletion of *gadA* significantly boosted 1,5-PDO production.
• The optimized strain S7 achieved 1.7 g/L in shake flasks and 12.45 g/L in bioreactor fermentation, with improved glucose yields and biomass accumulation.

Conclusions:

• Transcriptomics-guided reverse engineering is an effective strategy for identifying metabolic bottlenecks and optimizing microbial cell factories.
• The genes *fecA* and *gadA* were identified as key targets for enhancing 1,5-PDO biosynthesis.
• This study provides a foundation for further systems metabolic engineering of *E. coli* for efficient 1,5-PDO production.