Microbial synthesis of pyrogallol using genetically engineered Escherichia coli

Area of Science:

• Biotechnology
• Synthetic Biology
• Chemical Engineering

Background:

• Pyrogallol is a versatile phenolic compound with applications across multiple industries.
• Current commercial production via thermal decarboxylation of gallic acid faces limitations in raw material accessibility, harsh reaction conditions, and low yields.
• There is a need for efficient and sustainable methods for pyrogallol synthesis.

Purpose of the Study:

• To develop a novel and efficient biosynthetic pathway for pyrogallol production.
• To engineer Escherichia coli for the microbial synthesis of pyrogallol.
• To optimize pyrogallol production to gram-per-liter levels for potential industrial applications.

Main Methods:

• Identification and characterization of a 2,3-dihydroxybenzoic acid (2,3-DHBA) 1-monoxygenase for pyrogallol synthesis.
• Overexpression of 2,3-DHBA synthase and 2,3-DHBA 1-monoxygenase in E. coli.
• Optimization strategies including enhancing carbon flux via the shikimate pathway, modular pathway optimization, and alleviating pyrogallol autoxidation.

Main Results:

• Successful non-natural production of pyrogallol from 2,3-DHBA using the engineered enzyme.
• Achieved an initial pyrogallol titer of 201.52 mg/L in E. coli within 24 hours.
• Further optimization led to a significantly enhanced pyrogallol titer of 1035.75 mg/L in shake flask experiments.

Conclusions:

• Established an efficient microbial platform for the gram-per-liter level production of pyrogallol.
• Demonstrated the potential for industrial biomanufacturing of pyrogallol through a sustainable biosynthetic route.
• This work provides a foundation for scalable and cost-effective pyrogallol production.