Transcriptomic Changes in Response to Putrescine Production in Metabolically Engineered Corynebacterium glutamicum

Area of Science:

• Microbiology
• Metabolic Engineering
• Systems Biology

Background:

• Putrescine is a valuable industrial chemical produced using engineered microorganisms.
• Understanding the metabolic and physiological impact of putrescine overproduction in Corynebacterium glutamicum is crucial for strain improvement.

Purpose of the Study:

• To investigate the global transcriptional alterations in Corynebacterium glutamicum during putrescine overproduction.
• To identify potential targets for genetic modification to enhance putrescine yields.

Main Methods:

• Comparative transcriptomic analysis of engineered and wild-type Corynebacterium glutamicum strains.
• Utilizing CRISPR interference (CRISPRi) for targeted gene repression.

Main Results:

• Putrescine overproduction led to downregulation of genes involved in central carbon metabolism, oxidative phosphorylation, and biosynthesis pathways.
• Upregulation of ornithine biosynthesis and NADPH-generating enzymes was observed.
• Repression of ATP- and NADPH-consuming enzymes using CRISPRi significantly boosted putrescine production.

Conclusions:

• Transcriptional reprogramming occurs during putrescine overproduction in C. glutamicum, impacting various metabolic routes.
• Targeted repression of energy-consuming pathways offers a viable strategy for improving industrial putrescine biosynthesis.