Pilot Scale Production of a F₄₂₀ Precursor Under Microaerobic Conditions.

Area of Science:

• Biochemistry
• Biotechnology
• Metabolic Engineering

Background:

• Redox cofactors are crucial for biocatalysis, but limited availability hinders research.
• Coenzyme F₄₂₀ and its precursor F_O are important for redox reactions, yet low yields restrict their study.
• Previous work identified F_O as a potential surrogate for F₄₂₀ in certain enzymatic applications.

Purpose of the Study:

• To develop a scalable bioprocess for producing pure F_O from engineered Escherichia coli.
• To optimize downstream purification for obtaining relevant quantities of F_O.
• To investigate F_O biosynthesis dynamics within a pilot-scale bioreactor.

Main Methods:

• Engineered Escherichia coli host strain for heterologous fbiC expression.
• Implementation of oxygen-limited conditions in a 30-L pilot scale stirred tank bioprocess.
• Downstream purification process development.
• Online fluorescence monitoring for real-time biosynthesis tracking.

Main Results:

• Achieved a final titer of 5.05 mg L^-1 of F_O.
• Successfully shifted cofactor synthesis from riboflavin to F_O under optimized conditions.
• Demonstrated growth-associated F_O biosynthesis via online monitoring.
• Enabled purification of significant F_O amounts for further research.

Conclusions:

• The developed bioprocess and purification workflow provide a reliable method for obtaining substantial quantities of F_O.
• This advancement facilitates in-depth functional investigation of F_O-dependent enzymes and their biocatalytic potential.
• The study establishes a foundation for utilizing F_O as a key cofactor in biotechnological applications.