Formate-driven efficient pyruvate biosynthesis in Vibrio natriegens

Area of Science:

• Microbiology
• Metabolic Engineering
• Biotechnology

Background:

• Formic acid (FA) is a CO2-derived one-carbon compound with potential for green biomanufacturing.
• FA's toxicity and poor metabolizability hinder microbial production of value-added chemicals.
• Vibrio natriegens is a known proficient formic acid utilizer.

Purpose of the Study:

• To investigate the effect of formate supplementation on pyruvate production in V. natriegens.
• To engineer V. natriegens for improved pyruvate synthesis using formate and sodium gluconate.
• To establish a novel strategy for leveraging formate in microbial production.

Main Methods:

• Supplementation of V. natriegens cultures with formate and sodium gluconate.
• Transcriptomic analysis to understand gene expression changes.
• Genetic engineering to downregulate pyruvate consumption pathways.
• Isotopic tracer analysis for formate assimilation.
• Fed-batch fermentation for pyruvate production.

Main Results:

• Formate supplementation increased pyruvate titer by 1.9-fold.
• Engineered V. natriegens achieved a 49.0% improvement in pyruvate synthesis.
• Approximately 9.43% of assimilated formate was incorporated into biomass.
• The engineered strain produced 56.4 g/L pyruvate at a rate of 1.1 g/L/h in fed-batch fermentation.

Conclusions:

• Formate acts as a stimulatory substrate for pyruvate biosynthesis in V. natriegens.
• Downregulating pyruvate consumption enhances production efficiency.
• This study presents a novel strategy for utilizing formate in microbial production systems.
• V. natriegens shows promise as a cell factory for pyruvate production.