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Probing efficient microbial CO2 utilisation through metabolic and process modelling.
Philip J Gorter de Vries1, Viviënne Mol1, Nikolaus Sonnenschein2
1The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kongens Lyngby, Denmark.
Microbial Biotechnology
|February 21, 2024
Summary
Acetogenic gas fermentation can be optimized for waste gas upcycling. Modeling shows higher temperatures and specific H2:CO2 ratios improve yields, but expanding product range beyond acetate remains challenging.
Area of Science:
- Biotechnology
- Chemical Engineering
- Environmental Science
Background:
- Acetogenic gas fermentation offers a promising route for upcycling carbon-rich waste gases.
- Current limitations in product range, yield, rate, and titre hinder economic viability.
Purpose of the Study:
- To optimize acetogenic gas fermentation processes through integrated process and metabolic modeling.
- To explore conditions and strategies for expanding the product portfolio beyond acetate.
Main Methods:
- Paired process modeling and host-agnostic metabolic modeling were employed.
- Simulations were conducted for an industrial-scale bubble column reactor.
- Product volatility analysis and metabolic pathway modeling were utilized.
Main Results:
- Increased temperatures enhance gas transfer rates, especially for H2.
- An optimal feed composition of 9:1 mol H2 to mol CO2 was predicted.
- Thermophilic metabolism favors catabolic products; expanding product range is metabolically unfavorable compared to acetate/ethanol.
Conclusions:
- Process optimization can improve acetogenic gas fermentation efficiency.
- In-situ recovery of volatile products like acetone is feasible but challenging.
- Alternative strategies are needed to overcome metabolic limitations for producing diverse carbon-negative chemicals via acetogenic CO2 fixation.
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