A high-pressure bioreactor system for the cultivation of Methanothermobacter marburgensis on advanced growth media for sustainable energy applications

The global transition towards sustainable energy necessitates rapid innovations in renewable technology, with biomethanation emerging as a promising approach. Methanogenic archaea, notably Methanothermobacter marburgensis, play a pivotal role in the biogenesis of biomethane as a renewable energy vector. This research introduces a new second-generation Simultaneous Bioreactor System (SBRS-II), a high-pressure cultivation platform engineered to optimize microbial gas fermentation. A novel sulfate-based growth medium (MM-CF-S) was formulated to substitute conventional chloride salts, thereby minimizing corrosion risks in steel reactors and eliminating the toxic compound NiCl₂·6 H₂O, which enhances safety during large-scale deployment. Comparative analyses indicate that the new medium markedly boosts methane production rates, attaining a maximum of 285.86 ± 22.94 mmol L⁻¹ h⁻¹, approximately doubling the baseline. Additionally, metrics of biomass accumulation and specific methane productivity observed improvements, with reaching 216.85 ± 17.54 mmol g⁻¹ h⁻¹. The sulfate medium also preserved pH stability under high-pressure conditions, ensuring physiological viability essential for M. marburgensis proliferation. Integration of the SBRS-II platform with the MM-CF-S medium signifies a significant advancement toward scalable, efficient biomethanation technologies, highlighting the potential of methanogenic archaea in renewable energy applications and establishing a foundation for further process optimization to meet industrial-scale demands.