EUBCE 2026 - Raquel LEBRERO - Toward Efficient Syngas-To-Biomethane Conversion: The Role of Temperature and Microbial Synergy

Toward Efficient Syngas-To-Biomethane Conversion: The Role of Temperature and Microbial Synergy

Short Introductive summary

Syngas biomethanation, the microbial conversion of CO, CO2, and H2 into CH4, enables the valorisation of waste-derived gas streams into renewable biomethane. Mixed anaerobic consortia enriched in continuous bubble column bioreactors at 30 °C and 50 °C achieved biomethane contents near 85 %. Temperature was the main factor shaping both metabolic routes and community structure: mesophilic operation coupled hydrogenotrophic methanogenesis with acetate-based pathways, while thermophilic conditions favoured direct hydrogenotrophic methanogenesis driven by Methanothermobacter. Building on these results, defined co-cultures of Carboxydothermus hydrogenoformans and Methanothermobacter thermautotrophicus were tested to elucidate H2-mediated syntrophy, achieving 50.7 % CH4 in continuous mode in a biotrickling filter, well above monoculture performance. Overall, temperature and interspecies cooperation emerge as key factors to control carbon and electron flow, guiding the design of efficient, stable bioreactors for high-purity biomethane production from syngas.

R. Lebrero, Institute of Sustainable Processes, University of Valladolid, SPAIN
M.E.M. Yescas, Institute of Sustainable Processes, University of Valladolid, SPAIN
V. Rodríguez, Institute of Sustainable Processes, University of Valladolid, SPAIN
R. Muñoz, Institute of Sustainable Processes, University of Valladolid, SPAIN