Photoelectrocatalytic-microbial biohybrid for succinic acid synthesis

Area of Science:

• Biotechnology
• Renewable Energy
• Chemical Engineering

Background:

• Succinic acid is a key platform chemical, but traditional production is energy-intensive and unsustainable.
• Microbial production using Actinobacillus succinogenes is promising but limited by poor intracellular electron transfer.
• Developing sustainable chemical synthesis routes is crucial for reducing environmental impact.

Purpose of the Study:

• To engineer Actinobacillus succinogenes for enhanced electron transfer.
• To develop a photoelectrocatalytic-microbial biohybrid system for efficient succinic acid production.
• To couple solar energy with microbial metabolism for carbon-neutral chemical manufacturing.

Main Methods:

• Adaptive laboratory evolution with gold nanoparticles to improve charge transfer in Actinobacillus succinogenes.
• Immobilization of engineered bacteria onto a NiO@PAA@NHS photoelectrode.
• Construction of a NiO@PAA@NHS/Au@Actinobacillus succinogenes biohybrid system.
• Photoelectrocatalytic experiments under simulated solar illumination.

Main Results:

• Achieved a photocurrent density of 1.9 mA cm⁻².
• Demonstrated a CO2 conversion efficiency of 67%.
• Obtained a succinic acid production rate of 1.41 ± 0.04 g L⁻¹ h⁻¹ cm⁻².
• Engineered bacteria exhibited enhanced charge-transfer pathways.

Conclusions:

• The developed photoelectrocatalytic-microbial biohybrid system effectively overcomes metabolic bottlenecks in succinic acid production.
• This approach offers a scalable and carbon-neutral strategy for producing valuable chemicals from CO2 using solar energy.
• The study highlights the potential of integrating renewable energy technologies with microbial biosynthesis.