Fed-batch microbioreactor platform for scale down and analysis of a plasmid DNA production process

Area of Science:

• Biotechnology
• Bioprocess Engineering

Background:

• Rising costs of bioprocess R&D necessitate high-throughput, low-cost alternatives to bench-scale bioreactors.
• Existing platforms often lack advanced monitoring and control for complex operations like fed-batch or continuous culture.

Purpose of the Study:

• To develop and validate a 1-mL microbioreactor system for microbial process development.
• To enable advanced monitoring and control of key parameters in microbial cultures.
• To assess the scalability and predictive accuracy of the microbioreactor for bioprocesses.

Main Methods:

• Development of a 1-mL microbioreactor with online monitoring of dissolved oxygen, pH, temperature, and optical density.
• Utilized plasmid DNA (pVAX1-GFP) production in Escherichia coli using a fed-batch process as a model system.
• Validated the platform's predictive capabilities by comparing results with bench-scale bioreactor data across various feed rates.

Main Results:

• The microbioreactor accurately monitored and controlled critical process parameters.
• The system demonstrated robust prediction of cell growth, key metabolite concentrations (glycerol, acetate), and plasmid DNA yield and quality.
• Predictive accuracy was maintained across different feed rates when critical parameters like dissolved oxygen were consistent between scales.

Conclusions:

• The 1-mL microbioreactor offers a scalable, cost-effective platform for microbial bioprocess development.
• The device enables accurate prediction of bench-scale outcomes, facilitating high-throughput screening and optimization.
• This technology has broad applicability for various microbial processes beyond plasmid DNA production.