Mitigation of greenhouse gas emissions from biogas-producing facilities: A novel whole-cell technology platform based on anaerobic oxidation of methane

Biogas produced from anaerobic digestion of organic residues is nowadays a consolidated renewable fuel worldwide. Biogas, mainly composed of methane (CH4, 50%¿70%) and carbon dioxide (CO2, 30%¿50%), can be burned to generate heat and electrical power in a variety of engines and turbines. If CO2 is removed, the resulting CH4 stream can be injected into natural gas grids, making it an attractive source of renewable energy. However, recent studies warned about the large-scale methane emissions derived from the purge of the liquid phase of anaerobic digesters, known as digestate. An important fraction of the CH4 produced remains dissolved, being released to the atmosphere when digestate is purged. A novel whole-cell technology platform coupling CH4 oxidation with nitrate/nitrite reduction (N-AOM) is presented in this chapter. Process microbiology, bioreactor configurations, and key operating conditions for successful N-AOM implementation are addressed. Research niches and perspectives for the full-scale implementation are also discussed. © 2025 Elsevier Inc. All rights reserved.