Steger, F. | Search bioRxiv

bioRxiv2026

CFD-Informed Hybrid Modeling Unlocks Scalable, Tunable Amino Acid Production in Methanothermobacter marburgensis

Methanogenic archaea, such as Methanothermobacter marburgensis, represent a powerful biological platform for carbon capture and valorization, directly converting carbon dioxide (CO2) and molecular hydrogen (H2) into proteinogenic amino acids (AAs). In this study, we present a controlled and scalable strategy for tailoring AA production (biosynthesis and secretion) in continuous gas fermentation. By applying various Design of Experiments (DOE) techniques, we systematically identified and optimized key process parameters governing AA biosynthesis and shaping a targeted AA secretion profile. A hybrid modeling framework combining experimental data with scale-independent parameters derived from computational fluid dynamics (CFD) enabled robust performance prediction across bioreactor scales. This model-driven approach successfully translated the process from 120 mL glass bottles via 2 L to 150 L reactors, corresponding to a reaction-volume scale-up factor of 2000. These findings set the foundation for a robust and predictive platform for sustainable AA production, positioning archaea as a high-potential alternative in industrial biotechnology.

bioengineering↗

bioRxiv2025

Pilot-scale production of leucine from CO2

On a cellular level, proteinogenic amino acids (AAs) are the building blocks of proteins. On a global scale, AAs serve as important nutrients for humans and animals. Beyond their nutritional value, AAs are of relevance in medicine, and, due to their chemical properties, they are indispensable for applications in many different realms, such as pharmaceutics, cosmetics, animal feed, food, and the beverage industry. Here, we report the first archaeal cell factory for leucine production from CO2 that has been generated by rational design, random mutagenesis and pathway engineering. The cell factory has been bioprocess-technologically examined and successfully scaled-up with regard to productivity, product quality, and operational stability. In a 2-day fed-batch campaign, we produced 181 g of leucine from CO2 at 150 L pilot-plant scale at a mean volumetric leucine productivity of 65 mg L-1 h-1. A thorough techno-economic analysis indicates that the roll-out of leucine production from CO2 is nearly economically feasible on a global scale.

bioengineering↗